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Restoration implications of land management legacy on aboveground and seed bank composition of North American Grasslands.

Introduction

Tallgrass prairie once stretched from the Canadian provinces to the Texas panhandle in the interior of North America but today little remains. In eight of the 12 states of the U.S., in which this endangered biome once occurred, over 99% has been destroyed, a decline greater than any other North American biome (Samson and Knopf, 1994; Samson et al, 2004). The rarity of this biome is reflected by its high Conservation Risk Index rating--calculated at the "ratio of percent area converted to percent area protected as an index of relative risk of biome-wide biodiversity loss" (Hoekstra et al, 2005). Despite the tremendous prior losses and ongoing conservation efforts, tallgrass prairie continues to disappear.

Prairie restoration provides one avenue to bring back some of the lost prairie acreage and to restore ecosystem functionality (Foster el al, 2007). Frequently, the starting point for these restorations is an anthropogenic landscape that has been disturbed to varying degrees resulting in highly degraded prairies, pasture, and/or cropland. One prairie restoration approach is to manage prairie remnants to favor the growth of existing prairie species and to encourage emergence of any dormant prairie vegetation (Packard and Ross, 1997). A potential source of dormant prairie vegetation may be found in the soil seed bank.

Soil seed banks are defined as the dormant but viable seeds that lie in the soil (Bigwood and Inouye, 1988). Dormant seeds may persist for over 50 y (Chippindale and Milton, 1934) if conditions are not favorable for germination. Then, when conditions are favorable, these dormant seeds can germinate and seedlings emerge and establish. For this reason soil seed banks potentially provide a record of the species that once dominated a landscape and can be used to recover that diversity in the event that it is lost (Davies and Waite, 1998; Rabinowitz, 1981). Soil seed banks therefore serve as reservoirs of biodiversity (Thompson and Grime, 1979; Levin, 1990).

Several studies have questioned the potential role seed banks may contribute to prairie restoration efforts because: (1) the seed bank of prairies is absent or, at best, depauparate (Laughlin, 2003; Meiners and Gorchov, 1994; Wilson, 2002), and (2) the relationship between the prairie seed bank and aboveground vegetation is weak or nonexistent (Johnson and Anderson, 1986; McNicoll and Augspurger, 2010; Romo and Bai, 2004). Moreover, vegetative recruitment predominates in prairies. For example, Benson and Harnett (2006) determined that >99% of recruitment in existing prairies comes from vegetative growth, with <1% of recruitment from seed.

Despite these caveats, knowledge of existing seed banks, and the relationship between the seed bank and aboveground vegetation, particularly in relation to land-use history, can inform restoration efforts. For example knowledge of the seed bank of a site may promote informed decisions regarding which native species to add to seed mixes owing to their absence in the seed bank. Rosburg and Owens (2004) noted seed bank studies provide an evaluation tool for prairie restoration success and assist in determining the fate of the species that have been seeded. Although assessing the species composition of the seed bank may be a useful tool, knowledge of the land management history of a site is equally important as it may affect seed bank composition.

Grassland management influences the seed bank (Albrecht and Auerswald, 2009; Dutoit and Alard, 1995; Jacquemyn et al, 2011). Management practices impact both the species richness and composition of seed banks (Buhler et al, 2001; Dutoit and Alard 1995; Wellstein et al, 2007). Some grasslands lose plant species richness when management activities cease (Jacquemyn el al, 2011). Seed banks have even been shown to be sensitive to different land management practices in that seeds in frequently disturbed sites have a higher longevity period in the soil than infrequently disturbed sites (Albrecht and Auerswald, 2009). However, the link between management practices and seed bank composition is still poorly understood in Midwestern landscapes, particularly for prairies.

In this study we investigated standing vegetation and seed bank composition for replicate sites subject to six different land management histories at the largest grassland restoration east of the Mississippi River, the Midewin National Tallgrass Prairie (U.S.A.): remnant prairie, restored prairie, new (recently planted) pasture, active pasture, old field (abandoned or serai pasture), and crop field. In particular we determined: (1) the relationship between the standing vegetation and the seed bank composition and (2) effect of land management history on standing vegetation and seed bank composition. Based on the results of our study we provide much needed guidance regarding restoration efforts associated with different land types poise to be converted to prairies and the importance of (or lack of) both standing vegetation and seed bank composition as part of this process.

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Methods

STUDY SITE

This study was conducted at the Midewin National Tallgrass Prairie (hereafter Midewin, 41[degrees]20'29.2"N, 88[degrees]07'45.1"W), Will County, Illinois, U.S.A. (Fig. 1). This 7700 ha site, under management of the U.S. Forest Service, is being restored to a mosaic of prairie, savanna, forest, wetland, and grassland bird habitat. Prior to its transfer to the U.S. Forest Service, Midewin was under control of the U.S. Army as the Joliet Army Ammunition Plant from 1940 to 1996. During this period most of the approximately 4000 ha that was not used for munitions production was under agricultural or pastoral use. Approximately 80 ha of native vegetation remained when the U.S. Forest Service acquired the site in 1997. The arsenal did not manage these areas, with the exception of grazing. Although somewhat degraded these tracts are considered the best representation of remnant vegetation at the site. Fire management has been implemented since the U.S. Forest Service assumed management. Lastly, soils in the sites sampled at Midewin for this study were silty loam or silty clay loam.

FIELD AND GREENHOUSE PROCEDURES

Five replicate sites (n = 5) representing six different land management histories were surveyed at Midewin both vegetation and seed bank: restored prairie, remnant prairie, new pasture, active pasture, crop field, and old field (Fig. 1). The following criteria were used to select the different land management histories. Remnant prairie areas were selected based on the presence of a dominant matrix of native species and input from site managers that these areas had neither been plowed nor significantly disturbed. These sites supported a suite of mesic to wet mesic vegetation. Restored prairie sites were former crop fields and had been undergoing restoration efforts for fewer than 10 y. These areas supported mesic to wet mesic vegetation. New pasture sites were former crop fields planted to a mix of cool season grasses and exotic legumes within 10 y of our study. Active pastures consisted predominantly of cool season grasses and exotic legumes and had been maintained as pastures at least since the early 1940s when the site was under U.S. Army management as the Joliet Arsenal. Old field sites were former pastures no longer subject to grazing. These sites were mowed annually to control woody vegetation but otherwise received no management. Crop field sites were selected as areas that had been under agricultural production since the time the army began managing the area. At the time of the survey, these areas were in a rotation of glyphosate resistant soybeans (Glycine max) and winter wheat (Triticum aeslivum). Crop field sites were surveyed during years when soybeans were present.

At each site a vegetation survey was conducted along a 40 m transect with sampling occurring every 2 m and staggered to the left and the right of the transect. Each transect was placed in an area representative of the vegetation that is characteristics of each management type. Sampling took place by surveying a 0.25 [m.sup.2] quadrat located lm from the transect and recording the percent cover of all vegetation in the quadrat using a modified Daubenmire method (Daubenmire, 1959) for a total of 20 quadrats per transect. Vegetation surveys occurred in July 2009.

Soil cores were collected at 4 m intervals staggered to the left and the right along the same vegetation transect for a total of 10 cores per transect at each site. Soil cores were 3.18 cm in diameter and taken to a depth of 10 cm. Soil surveys occurred in October 2009 to capture as much of the previous year's seed rain as possible. A total of 300 soil cores was collected for this study. Soil cores were bagged and refrigerated at 3 C until April 2010 when they were processed and placed in the greenhouse to begin germination. Processing consisted of breaking of the cores mechanically over a mesh screen to remove any roots or other nonseed propagules (i.e., bud bank) and to provide some degree of separation of the soil. The soil cores were spread over a greenhouse soil mixture in 28 cm W X 54 cm L X 6 cm D flats, and seedling emergence was tracked on a weekly basis. Seedlings were identified to the species level and removed after identification. Germination was followed until January 2011, when new seedling emergence ceased. Control flats were used to determine if there were greenhouse contaminants. In addition trays were rotated on a weekly basis to avoid bench effects. Temperature was kept as constant as possible [i.e., 16-26 C (depending on the outside night/day temperatures)] and natural lighting was supplemented by artificial lighting throughout the project for a 14 h day photoperiod. Storage of soils and greenhouse work were conducted at the Illinois Natural History Survey Greenhouse Facilities, Champaign, Illinois.

DATA ANALYSIS

For each site we calculated species richness, Shannon diversity (H') and species evenness (H'/lnS) for the aboveground vegetation and the seed bank by pooling the data from each quadrat per per transect per site. We also calculated the following summary statistics per land management history: relative species frequency, percent native species, percent nonnative species, percent weedy species, total species richness, graminoid species richness, forb species richness, and woody species richness (Appendix 1 and 2). We considered weedy species to be any nonnative and native species having a coefficient of conservatism value of three or less, thus being characteristic of ruderal environments (see Taft et al, 1997 for more details).

We compared species richness, diversity and evenness with respect to the main effects of location (above-below ground) and land management history, and the interactions of location X richness, location X diversity and location X evenness with multivariate analysis of variance (MANOVA). As each main effect was significant, we followed the MANOVA with univariate F-tests and Tukey post hoc tests to investigate each main effect separately. We conducted the follow-up univariate F-tests separately for aboveground vegetation and for the seed bank composition, investigating the effects of land management history on species richness, Shannon diversity and evenness. We feel this is justified, despite the significant interactions, because the species compositions above- and below ground are quite distinct and doing so allowed post hoc tests to locate differences in species richness, Shannon diversity and species evenness among land management histories contingent upon location above- or below-ground (Scheiner, 1993).

To meet the assumptions of normality and/or equality of variance for the analysis of species richness, data were subjected to the [log.sub.10](n + 1) transformation, and for the purpose of data presentation, data were back-transformed. Because above ground vegetation was quantified as percent cover, and the seed bank was quantified as species abundances, we used species presence-absence on a site level to compare above- and below-ground species composition.

We used a Mantel lest (McCune and Mefford, 2011) based on Bray-Curtis similarities to measure the correlation between corresponding positions of the matrix of aboveground species composition by land management history with the matrix of seed bank species composition by land management history. The test is based on 1000 randomized permutations.

We used a permutational analysis of variance (perMANOVA; Anderson, 2001; McCune and Mefford, 2011) based on Bray-Curtis similarities to test directly whether location (abovebelow ground), land management history, or their interaction affected species composition. We used 5000 permutations in each of the analyses. Because the perMANOVA indicated that species composition in the six land management histories was contingent upon location (above-below ground), we conducted a separate perMANOVA for each location. Doing so allowed us to test for differences among land management histories in species composition among the different land management histories with post-hoc pairwise comparisons.

Lastly, to visualize any multivariate patterns identified with the perMANOVA, species composition of aboveground vegetation, the below' ground seed bank, and the combined data for both based on land management history were displayed using non-metric multidimensional scaling (NMDS) of Bray-Curtis similarity matrices with PC-ORD (McCune and Mefford, 2011). For the NMDS ordinations of the aboveground vegetation and the seed bank separately, three-dimensional solutions were chosen to reduce stress while still enabling an interpretable graphical depiction of results. For the NMDS ordination of aboveground vegetation and the seed bank together we opted for a two-dimensional solution. Stress for the NMDS was interpreted based on Borg and Groenen (2005).

Results

SUMMARY STATISTICS

Aboveground vegetation.--Altogether, 226 plant taxa were Identified to genus or species level during field surveys (Appendix 1). Of these, about 20% were graminoids, 72% were forbs, with the remainder woody (Appendix 2). The most frequently observed species were Poa pratensis (61.5%), Daucus carota (47.9%), Solidago canadensis (42.5%), and Promus inermis (38.7%). Nonnative species comprised 18.6% and native species comprised 81.4% of the aboveground vegetation. Weedy species accounted for 57.0% of the observed aboveground vegetation cover.

Seed bank.--A rapid emergence of seedlings occurred within the first nine weeks followed by a slow tapering off of new emergence after that period. Altogether, 2096 seedlings germinated from the seed bank. Most of the seedlings (86.8%) were identified to the species or genus level. A total of 91 species were identified from the seed bank (Appendix 1), including 22% graminoid species and 75% forb species (Appendix 2). The most abundant species were Mollugo verticillala (6.4 %), Oxalis slricta (6.4%), Setaria Jaberi (6.0%), and Veronica peregrina (6.0%). Mollugo verticillala was highly concentrated in a single sample, with over 87% of the individuals found in the entire study coming from a single site (restored prairie site 3, Appendix 2). Nonnative species comprised 22% of the seed bank composition. Weedy species accounted for 87.0% of the observed seedlings. By the ninth week 85.1% of the total observed seedlings had been observed. The remaining 14.9% germinated and were observed over the following 21 w of the study. Of the 2096 seedlings, 844 emerged from soil cores from restoration sites, 316 emerged from old pasture sites, 300 emerged from new pasture sites, 299 emerged from old field sites, 214 emerged from remnant sites, and 123 emerged from crop fields.

Species composition of aboveground vegetation and the seed bank.--Of the 248 species observed in the study, 157 were found only in the aboveground vegetation, and 22 were found only in the seed bank (Appendix 1). Sixty-nine species were found both aboveground and in the seed bank. Hence, the seed bank contained only 30.5% of the species found in the aboveground vegetation, while the aboveground vegetation contained 75.8% of the species found in the seed bank. Of the 248 species observed, 58 were nonnative, 27 aboveground, 10 in the seed bank, and 21 in common.

MULTIVARIATE ANALYSIS

Species richness and diversity.--Both the main effect of location (Wilk's [[lambda].sub.3,46] = 0.49, F = 16.2, P < 0.001) and the main effect of land management history (Wilk's [[lambda].sub.15,127] = 0.161, F = 7.96.8, P < 0.001), and their interaction (Wilk's [[lambda].sub.15,127] = 0.476, F = 2.6, P = 0.002) were significant in the MANOVA. The significant interaction of location and land management history appears due to all land management histories having greater species richness, Shannon diversity, and evenness above than below ground except for crop fields, in which both species richness, Shannon diversity, and evenness are virtually identical above and below ground, and for prairie restorations, for which evenness is greater below than above ground (Figs. 2, 3, and 4).

Aboveground vegetation.--A univariate F-test indicated mean aboveground species richness varied significantly by land management history ([F.sub.5,24] = 20.1, P < 0.001; Fig. 2). Remnants had the highest overall species richness (Appendix 2). Species richness was significantly greater in remnant prairie, prairie restorations and old fields than in active pastures, new pastures and crop fields. Species richness did not differ between active and new pastures, both of which had greater richness than crop fields.

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A univariate F-test indicated that mean aboveground Shannon diversity differed significantly among land management history ([F.sub.5,24] = 19.6, P < 0.001; Fig. 3). The Shannon diversity was significantly greater in prairie restorations and prairie remnants than in old pastures, active pastures and crop fields, but did not differ from that in old fields. The Shannon diversity was also significantly greater in old fields than in new pastures and crop fields but did not differ from that in active pastures. Shannon diversity was significantly lower in crop fields than in all other land management histories.

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A univariate F-test indicated that mean aboveground species evenness differed significantly among land management histories ([F.sub.5,24] = 4.6, P = 0.005; Fig. 4). Species evenness was significantly greater in prairie remnants, active pastures, and new pastures than in prairie restorations, but did not among any other pairs of land management histories.

Seed bank.--A univariate F-test indicated that mean seed bank species richness differed significantly by land management history ([F.sub.5,24] = 10.4, P < 0.001; Fig. 2). Prairie restorations had the highest seed bank species richness, followed by prairie remnants and old fields, active pastures, new pastures, and crop fields (Appendix 2). Species richness was significantly lower in crop fields than in all other land management histories. Species richness did not differ significantly among any other land management histories.

A univariate F-test indicated mean seed bank Shannon diversity differed significantly by land management history ([F.sub.5,24] = 6.2, P = 0.001; Fig. 3). Seed bank Shannon diversity was significantly lower in crop fields than in all other land management histories except new pastures. Seed bank Shannon diversity did not differ significantly among any other land management histories.

A univariate F-test indicated that seed bank species evenness did not differ significantly among any of the six land management histories ([F.sub.5,24] = 1.6, P = 0.17; Fig. 4).

Species composition of aboveground vegetation and the seed bank.--The Mantel test revealed a significant, positive correlation among corresponding positions of the aboveground and seed bank similarity matrices (Standardized Mantel test statistic r = 0.508, P < 0.001). Hence, the tracts that are most similar in aboveground species composition are highly and positively correlated with the corresponding tracts within the seed bank.

Consistent with the aboveground and seed bank compositional characteristics described above, perMANOVA found that the main effects of location ([F.sub.5,24] = 4.5, P < 0.001) and land management history ([F.sub.1,48] = 9.9, P < 0.001), and their interaction ([F.sub.5,48] = 2.1, P < 0.001) significantly affected species composition. Pairwise comparisons among aboveground land management histories indicates that species composition of all land management histories differed from all others with three exceptions: active pastures did not differ from old fields and crop fields; and prairie restorations did not differ from prairie remnants. Pairwise comparisons among seed bank land management histories indicates that all land use management histories did not differ from all others with four exceptions: crop fields differed from active pastures and old fields; and new pastures differed from old fields and prairie remnants.

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Nonmetric multidimensional scaling.--Nonmetric multidimensional scaling (NMDS) ordination of aboveground vegetation species composition graphically depicts the clustering of sites based on land management history expected from the perMANOVA (Figs. 5A-C). Specifically, the significant differences in species composition among different land use histories are most clearly evident when visualizing the ordination with axes 1 vs. 2 and axes 1 vs. 3. The similarity of species compositions of active pastures with both crop fields and old fields and of prairie remnants and prairie restorations are evident when visualizing the ordination with axes 2 and 3.

Nonmetric multidimensional scaling ordination of seed bank species composition graphically depicts the clustering of sites based on land management history expected from the perMANOVA (Figs. 6A-C). Specifically, the general absence of significant differences in seed bank species composition among different land use histories is most clearly evident when visualizing the ordination with axes 1 vs. 2. The four significant differences among land management histories, between crop fields and active pastures and old fields, and between new pastures and old fields and prairie remnants, are evident when visualizing the ordination with axes 1 and 3 and axes 2 and 3.

Lastly, the NMDS ordination of the combined aboveground vegetation and seed bank data with respect to land management history illustrates the interaction effect of the perMANOVA (Fig. 7).

DISCUSSION

Land management history clearly impacts the species composition, species richness, species diversity, and species evenness of the aboveground vegetation. Prairie remnants and prairie restorations possessed the greatest species richness and Shannon diversity in their aboveground vegetation compared to the other land management histories. This result was expected because both remnants and restorations are typically managed for a diverse assemblage of species. In contrast, species evenness of aboveground vegetation was greater in prairie remnants, new pastures and active pastures than in new restorations, but exhibited no other significant differences among all other land management histories. The differences found in aboveground vegetation among the different land management histories were largely not apparent in the seed bank. Given that even relatively undisturbed sites in this study (i.e., remnant prairies) showed a depauperate seed bank when compared to the aboveground vegetation, seed banks simply appear to be intrinsically less rich and of lower diversity than their aboveground counterparts, regardless of management practices. Unsurprisingly, given their intense agricultural management, both the aboveground vegetation and the seed bank of crop fields possessed the fewest species and least diversity, though they had relatively high evenness.

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The land management histories at Midewin included in this study may be roughly divided into those that are aimed at increasing native floral diversity (management of prairie remnant and prairie restoration), those that are aimed at agricultural production (active pasture, new pasture, and crop field), and one which is essentially "hands off' (management of old field). We found agricultural management leads to reduced aboveground species richness and Shannon diversity with respect to that found in prairie remnants, prairie restorations, and even old fields. By contrast all land management histories had reduced species richness and Shannon diversity in the seed bank, and none differed in species evenness. Mode of reproduction (i.e., sexual vs. asexual reproduction) could provide a potential explanation for the reduced species richness and diversity of the seed bank. Many plant species rely predominantly on vegetative rather than sexual reproduction, and hence produce relatively small seed crops in most years (Ott and Hartnett, 2011). These plants can be present in the aboveground vegetation, but since they do not rely heavily on seed for reproduction, they may be absent or poorly represented in the seed bank. Major prairie grasses such as Andropogon gerardii and Sorghastrum nutans reproduce vegetatively (McKendrick et al., 1975; Ott and Hartnett, 2015) as do a variety of prairie forbs, such as Vemonia baldwinii, Solidago canadensis, Pityopsis graminifolia, and Silphium speciosum (Hartnett, 1990).

In this study prairie remnants, prairie restorations, and old fields

each had much greater species richness and Shannon diversity aboveground than in the seed bank, whereas crop fields, and both active and new pastures each had relatively similar richness and Shannon diversity in both (Figs. 2 and 3). Similar richness and diversity in these more agriculturally-managed land uses are not surprising and have been found previously (Lopez-Marino et al., 2000). The short-term potential for recovery of these agriculturally-managed sites is exhibited by comparison with the old field sites, which had, until recently, been managed as active pasture. Simply removing grazing and allowing the sites to exist in the absence of this intensive management led to increases in species richness and Shannon diversity, reverting to a more natural state over time (Inouye et al., 1987). However, under current conditions, this management history is resulting in a more floristically diverse seed bank than the aboveground vegetation.

The Mantel test and the NMDS ordinations show that similar land management histories have similar aboveground vegetation compositions and similar seed bank compositions, even though the species compositions above ground differ from the corresponding seed bank species compositions (Figs. 5-7). In addition the NMDS ordinations illustrate that crop field sites separate within the state spaces from other land management histories. This result shows that intensive agricultural management in crop fields sets them apart from other land uses. Because prairie restorations and new pastures had been recently converted from crop fields, the similarity of their seed banks is perhaps to be expected. The similarity of the seed banks of these land management histories, coupled with their distinctiveness from seed banks of prairie remnants and old fields, suggests that there may be a lag time before a new cover type builds a seed bank that is representative of the aboveground vegetation.

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The aboveground vegetation carried a higher proportion of the seed bank flora than vice versa. Many of the species found only in the seed bank are weedy colonizer species (e.g., Chamaesyce maculala, Digitaria sanguinalis, Mollugo verlidllata), some of which flower early {e.g., Capsella bursa-pastoris, Cardamine hirsuta, Thlaspi arvense) and may have senesced by the time the vegetation surveys occurred in July. These species may well have been present in the aboveground vegetation and were simply missed during our surveys. They may also be persistent elements of the seed bank waiting for a significant disturbance event to colonize newly available habitat. Previous studies have established that weed emergence can depend highly on local conditions and recent land management history (Forcella el al., 1997; Smith and Gross, 2006).

The large number of species present in the aboveground vegetation but not evident in the seed bank for the prairie remnant, prairie restoration, and old field sites was expected based on previous studies (McNicoll and Augspurger, 2010; Romo and Bai, 2004; Rosburg and Owens, 2004; Schott and Hamburg, 1997; Sluis, 2002; Willand el al., 2013). We do not know if some (or all) of these species were present in the seed bank and conditions were simply not right for germination, or whether the seed for these species was absent from our seed bank samples. Alternatively, other factors not accounted for in our study may decrease seed production, and therefore, limit seeds present in the seed bank. Today most natural vegetation in Illinois exists as isolated remnants in an otherwise heavily degraded landscape matrix (Warner, 1994). An absence or alteration of pollinators (Goulson et al, 2008), seed dispersers (Nathan and Muller-Landau, 2000), or a reduced genetic pool (Menges, 1991; DeMauro, 1994) could all lead to a lower than expected seed set. A reduced seed set for many species could result in fewer contributions to the seed bank, despite those species being present in the aboveground vegetation.

The heavy emergence of weedy species in the seed bank samples may possibly be a result of the methods used in this study. Most weedy species are adapted to thriving in disturbed areas, which are typically characterized by bare soil and regular disturbance (Hobbs and Huenneke, 1992). Greenhouse trays full of regularly watered soil fit these characteristics closely. The presence of these weedy species in the seed bank and their readiness to germinate given the proper conditions should be a source of concern for restoration practitioners, as vegetation emerging from the seed bank may impede restoration efforts (Larson et al, 2011). Likewise, studies from agricultural research have shown that weedy seed banks will vary depending on the management practices and have the potential to impact cropping efforts (Dessaint et al., 1997; Menalled et al, 2001). For the restoration practitioner, the good news is that management practices such as site preparation by using herbicide application, tilling, and burning can help contain weedy species and help ensure a successful restoration (Blumenthal el al., 2005).

Many studies have investigated the relationship between aboveground vegetation and seed bank in grasslands (Auestad et al., 2013; Benson and Hartnett, 2006; Chippindale and Milton, 1934; Johnson and Anderson, 1986; Laughlin, 2003; Leicht-Young et al., 2008; McNicoll and Augspurger, 2010; Meiners and Gorchov, 1994; Perez et al, 1998; Rabinowitz, 1981; Thompson and Grime, 1979; Torok et al, 2009). Although Hopfensperger (2007) noted that in grasslands composition of the aboveground vegetation and the seed bank are more similar than they are in both forests and wetlands, the overall pattern of similarity between the seed banks and aboveground vegetation for grasslands varies depending on the type of grassland. For example aboveground vegetation and the seed bank exhibited little similarity in both European mesic grasslands (Wellstein et al, 2007) and European wet swales (Blomqvist et al, 2003). Likewise, in North America, many studies report little similarity between the seed bank and the aboveground vegetation in prairies (Johnson and Anderson, 1986; McNicoll and Augspurger, 2010; Perez el al., 1998; Rabinowitz, 1981), marshes (Wilson el al, 1993) and pastures (Coffin and Laurenroth, 1989), consistent with our findings. Regardless of the management history, the composition, species richness, Shannon diversity and species evenness of aboveground vegetation differed from the seed bank, with all measures generally significantly greater aboveground than in the seed bank.

Two caveats of this study need acknowledgement. First, seed bank composition studies, including ours, have limitations. At each step in the process of a seed bank study species may be missed. A number of factors may influence the outcome of a seed bank study including number and size of soil cores, greenhouse conditions during seed germination, or other environmental factors that cannot be replicated in a greenhouse. For these reasons, we follow the philosophy of Thompson and Grime (1979) that seed bank studies are "not designed to provide a complete assessment of the seed flora present," but are still the best means available to determine the composition of the seed bank.

Second, the comparison of aboveground vegetation and seed bank should be interpreted cautiously. As just noted, several aspects influence seedling emergence in the greenhouse, and thus a complete assessment of the seed bank is not possible. In addition a one time assessment of the above ground vegetation will miss some species. Nonetheless, the differences between the aboveground vegetation and seed bank we found have been observed in other grassland studies (Johnson and Anderson, 1986; McNicoll and Augspurger, 2010; Perez et al., 1998; Rabinowitz, 1981), lending credence to our results and their interpretation. A particularly interesting Finding is that, in some cases, the seed bank of a less intensively managed site (old field) possesses greater species richness and greater quality (from the perspective of an absence of weedy species) than the above ground vegetation of a more intensively manage site (active pasture).

In conclusion we found significant differences between the seed bank and aboveground vegetation in species richness, Shannon diversity, and composition. The absence of many species in the seed bank flora does not provide much hope, therefore, for the recovery of lost species from seed bank sources. However, our study sites have experienced various human disturbances over extended periods of time. Recently disturbed habitats may still have some native seeds that can be encouraged to germinate and thrive with proper management. From the findings of this study, we suggest the seed banks are neither reliable predictors of future states, nor indicators of past states, at least in North American prairies. Realizing the challenges presented by the seed bank is nonetheless an important part of any restoration effort. Further research into dealing with those challenges will help provide new tactics to maximize restoration potential.

Acknowledgments.--We thank the USDA Forest Service for permission to work at Midewin. We are grateful to Jamie Ellis, Paul Marcum, Jean Mengelkoch, Connie Carroll-Cunningham, Loy R. Phillippe, Cindy Jablonski, Rick Larimore. Jim Moody, Jason Willand, Mary Ann Feist, Valerie Sivicek, and Midewin National Tallgrass Prairie staff for fieldwork assistance. Thanks to Jeff Matthews, Janice Coons, and anonymous reviewers for comments. We thank Emily Minor for sharing her expertise on multivariate community analyses and for allowing us to use her lab's computers, and Danielle Ruffatto for help with figures. This study was supported through an Illinois Department of Natural Resources-C2000 Program grant.

LITERATURE CITED

Albrecht, H. and K. Auerswald. 2009. Seed traits in arable weed seed banks and their relationship to land-use changes. Basic Appl. Ecol, 10:516-524.

Anderson, M. J. 2001. A new method for non-parametric multivariate analysis of variance. Austral Ecol., 26:32-46.

Auestad, I., K. Rydgren, and J. P. Spindelbock. 2013. Management history affects grassland seed bank build-up. Plant EcoL, 214:1467-1477.

Benson, E. J. and D. C. Hartnett. 2006. The role of seed and vegetative reproduction in plant recruitment and demography in tallgrass prairie. Plant Ecol., 187:163-178.

Bigwood, D. and D. Inouye. 1988. Spatial pattern analysis of seed banks: an improved method and optimized sampling. Ecology, 69:497-507.

Blomqvist, M. M., R. M. Bekker, and P. Vos. 2003. Restoration of ditch bank plant species richness: the potential of the soil seed bank. Appl. Veg. Sci., 6:179-188.

Blumenthal, D. M., N. R. Jordan, and E. L. Svenson. 2005. Effects of prairie restoration on weed invasions. Agr. Ecosyst. Envir., 107:221-230.

Borc., I., and P. J. F. Groenen. 2005. Modern multidimensional scaling: theory and applications, 2nd ed. New York: Springer.

Buhi.f.r, D., K. Kohler, and R. Thompson. 2001. Weed seed bank dynamics during a five-year crop rotation. Weed Technol., 15:170-176.

Chippindale, A. H. G. and W. E. J. Milton. 1934. On the viable seeds present in the soil beneath pastures. J. Ecol., 22:508-531.

Coffin, D. P. and W. K. Laurf.nroth. 1989. Spatial and temporal variation in the seed bank of a semiarid grassland. Am. J. Bot,, 76:53-58.

Daubenmire, R. 1959. A canopy-coverage method of vegetational analysis. Northwest Sci., 33:43-64. Davies, A. and S. Waite. 1998. The persistence of calcareous grassland species in the soil seed bank under developing and established scrub. Plant Ecol., 136:27-39.

DeMauro, M. M. 1994. Development and implementation of a recovery program for the federally threatened lakeside daisy (Hymenoxis acaulis var. glabra), pp. 298-321. In: M. L. Bowles and C.J. Whelan (eds.). Restoration of Endangered Species. Conceptual Issues, Planning, and Implementation. Cambridge University Press, New York.

Dessaint, F., R. Ciiadoeuf, and G. Barralis. 1997. Nine years' soil seed bank and weed vegetation relationships in an arable field without weed control. J Appl. Ecol., 34:123-130.

Dutoit, T. and D. Aiard. 1995. Permanent seed banks in chalk grassland under various management regimes: their role in the restoration of species-rich plant communities. Biodivers, and Consent., 4:939-950.

Forceela, F., R. G. Wilson, J. Dekker, R. J. Kremer.J. Cardina, R. L. Anderson, D. Alm, K. A. Renner, R. G.

Harvey, S. Clay, and D. D. Buhler. 1997. Weed seed bank emergence across the corn belt. Weed Sri., 45:67-76.

Foster, B. L., C. A. Murphy, K. R. Keller, T. A. Aschenbach, E. J. Questad, and K. Kjndscher. 2007. Restoration of prairie community structure and ecosystem function in an abandoned hayfield: a sowing experiment. Restor. Ecol., 15:652-661.

Goulson, D., G. C. Lye, and B. Darvili.. 2008. Decline and conservation of bumble bees. Annu. Rev. EntomoL, 53:191-208.

Hartnett, D. C. 1990. Size-dependent allocation to sexual and vegetative reproduction in four clonal composites. Oecologia, 84:254-259.

Hobbs, R. J. and L. F. Huenneke. 1992. Disturbance, diversity, and invasion: implications for conservation. Consent. Biol., 6:324-337.

Hoekstra, J. M., T. M. Boucher, T. H. Ricketts, and C. Roberts. 2005. Confronting a biome crisis: global disparities of habitat loss and protection. Ecol. Lett., 8:23-29.

Hopfenspf.rger, K. N. 2007. A review of similarity between seed bank and standing vegetation across ecosystems. Oikos, 116:1438-1448.

Inouye, R., N. Huntly, D. Tilman, J. Tester, M. Stillwell and K. Zinnel. 1987. Old-field succession on a Minnesota sand plain. Ecology, 68:12-26.

Jacquemyn, H., C. Van Mechf.lf.n, R. Brys, and O. Honnay. 2011. Management effects on the vegetation and soil seed bank of calcareous grasslands: an 11-year experiment. Biol. Consent., 144:416-422.

Johnson, R. G. and R. C. Anderson. 1986. The seed bank of a tallgrass prairie in Illinois. Am. Mid. Nat., 115:123-130.

Larson, D. L., J. Bright, P. Drobney, J. L. Larson, N. Paiaia, P. A. Rabie, S. Vacek, and D. Wells. 2011. Effects of planting method and seed mix richness on the early stages of tallgrass prairie restoration. Biol. Consent., 144:3127-3139.

Laughlin, D. C. 2003. Lack of native propagules in a Pennsylvania, USA limestone prairie seed bank: futile hopes for a role in ecological restoration. Nat. Areas J., 23:158-164.

Leicht-Young, S. A., N. B. Pavlovic, R. Grunoei., and K. J. Frohnapple. 2008. A comparison of seed banks across a sand dune successional gradient at Lake Michigan dunes (Indiana, USA). Plant Ecol., 202:299-308.

Levin, D. 1990. The seed bank as a source of genetic novelty in plants. Am. Nat., 135:563-572.

Lopez-Marino, A., E. Luis-Calabuig, F. Fillat, and F. F. Bermudez. 2000. Floristic composition of established vegetation and the soil seed bank in pasture communities under different traditional management regimes. Agr. Ecosyst. Envir., 78:273-282.

McCune, B. and M. J. Mefford. 2011. PC-ORD. Multivariate analysis of Ecological Data, Version 6.0 for Windows.

McKendrick, J. D., C. E. Owensby, and R. M. Hyde. 1975. Big bluestem and indiangrass vegetative reproduction and annual reserve carbohydrate and nitrogen cycles. Agro-Ecosyst., 2:75-93.

McNicoll, M. B. and Augspurger, C. K. 2010. A comparison of vegetation and seed bank community structure in a sand prairie in Illinois, U.S.A. Am. Mid. Nat., 164:136-150.

Meiners, S. J. and D. L. Gorchov. 1994. The soil seed pool of Huffman Prairie, a degraded Ohio prairie, and its potential in restoration. Ohio J. Sri., 94:82-86.

Menalled, F., K. Gross, and M. Hammond. 2001. Weed aboveground and seedbank community responses to agricultural management systems. Ecol. Appl., 11:1586-1601.

Menges, E. S. 1991. Seed germination percentage increases with population size in a fragmented prairie species. Conserv. Biol., 5:158-164.

Nathan, R. and H. Muller-Landau. 2000. Spatial patterns of seed dispersal, their determinants and consequences for recruitment. Trends Ecol. Evol., 15:278-285.

Ott, J. P. and D. C. Hartnett. 2011. Bud production and dynamics of flowering and vegetative tillers in Andropogon gerardii (Poaceae): the role of developmental constraints. Am. J. Bot., 98:1293-1298.

-- and --. 2015. Vegetative reproduction and bud bank dynamics of the perennial grass Andropogon gerardii in mixedgrass and tallgrass prairie. Am. Mid. Nat., 174:14-32.

Packard, S. and L. M. Ross. 1997. Restoring remnants, pp. 63-88. In: S. Packard and C. F. Mutel (eds.).

The tallgrass restoration handbook: for prairies, savannas, and woodlands. Washington DC: Island Press.

Perez, C. J., S. S. Waller, L. E. Moser, J. L. Subbendieck, and A. A. Steuter. 1998. Seedbank characteristics of a Nebraska sandhills prairie. J. Range Manage., 51:55-62.

Rabinowitz, D. 1981. Buried viable seeds in a North American tail-grass prairie: the resemblance of their abundance and composition to dispersing seeds. Oikos, 36:191-195.

Romo, J. T. and Y. Bal 2004. Seed bank and plant community composition, mixed prairie of Saskatchewan. J. Range Manage., 57:300-304.

Rosburg, T. R. and M. Owens. 2004. The Seed Bank of a Reconstructed Prairie, pp. 44-54. In: D. Egan and J. A. Harrington (eds.). Proceedings of the 19th North American Prairie Conference: the conservation legacy lives on ..., University of Wisconsin-Madison, Wisconsin.

Samson, F. and F. Knopf. 1994. Prairie conservation in North America. BioScience, 44:418-421.

--, --, and W. R. Ostlie. 2004. Great Plains ecosystems: past, present, and future. Wildlife Soc. B., 32:6-15.

Scheiner, S. M. 1993. MANOVA: multiple response variables/multispecies interactions, pp. 94-112. In: S. M. Scheiner and J. Gurevitch (eds.). Design and Analysis of Ecological Experiments. Chapman Sc Hall, New York, New York.

Schott, G. W. and S. P. Hamburg. 1997. The seed rain and seed bank of an adjacent native tallgrass prairie and old field. Can. J. Bot., 75:1-7.

Sluis, W. J. 2002. Patterns of species richness and composition in re-created grassland. Restor. Ecol., 10:677-684.

Smith, R. G. and K. L. Gross. 2006. Rapid change in the germinable fraction of the weed seed bank in crop rotations. Weed Sci., 54:1094-1100.

Taft, J. B., G. S. Wilhelm, D. M. Ladd, and L. A. Masters. 1997. Floristic quality assessment for vegetation in Illinois a method for assessing vegetation integrity. Eugenia, 15:3-23.

Thompson, K. and J. P. Grime. 1979. Seasonal variation in the seed banks of herbaceous species in ten contrasting habitats. J. Ecol., 67:893-921.

Torok, P., G. Mates, M. Papp, and B. Tothmeresz. 2009. Seed bank and vegetation development of sandy grasslands after goose breeding. Folia Geobot., 44:31-46.

Warner, R. E. 1994. Agricultural land use and grassland habitat in Illinois: future shock for Midwestern birds? Conserv. Biol., 8:147-156.

Welustein, C., A. Otte, and R. Wai.diiardt. 2007. Seed bank diversity in mesic grasslands in relation to vegetation type, management and site conditions. J. Veg. Sci., 18:153-162.

Willand, J. E., S. G. Baer, D. J. Gibson, and R. P. Klopf. 2013. Temporal dynamics of plant community regeneration sources during tallgrass prairie restoration. Plant Ecol., 214:1169-1180.

Wilson, S. D. 2002. Prairies, pp. 443-464. In: A. J. Davy and M. R. Perrow (eds.). Handbook of Ecological Restoration. Cambridge, UK: University Press.

--, D. R. J. Moore, and P. A. Keddy. 1993. Relationships of marsh seed banks to vegetation patterns along environmental gradients. Freshwater Biol, 29:361-370.

Submitted 17 June 2015

Accepted 8 April 2016
APPENDIX 1.--Comprehensive list of species unique to either the
aboveground community, seed bank or shared between the two from
transects sampled at Midewin National Tallgrass Prairie, Will County,
Illinois. Nonnative species are indicated by an *

                                                   Aboveground and
Aboveground only           Seed bank only             seed bank

Acer saccharinum       Aristida oligantha       Abutilon theophrasti *
Achillea               Capsella                 Acalypha rhomboidea
millefolium *          bursa-pastoris *
Agalinis auriculata    Cardamine hirsuta *      Agrostis gigantea *
Agalinis tenuifolia    Carex tribuloides        Amaranthus
                                                  tuberculatus
Agrimonia              Cyperus esculentus       Ambrosia
parviflora                                      artemisifolia
Agrimonia pubescens    Cyperus strigosus        Ambrosia trifida
Allium cemuum          Descurainia sophia *     Barbarea vulgaris *
Andropogon gerardii    Dicanthelium             Bras sica sp.
                         acuminatum
Antennaria neglecta    Digitaria                Carex sp.
                         sanguinalis *
Apocynum cannabinum    Juncus interior          Cerastium fontanum *
Asclepias incamata     Leucospora multifida     Chamaecrista
                                                  fasdculata
Asclepias              Mollugo vertidllata *    Chamaesyce maculata
  sullivantii
Asclepias syriaca      Nepeta cataria *         Chenopodium album *
Asclepias              Panicum clandestinum     Cirsium arvense *
  vertidllata
Baptisia ladea         Panicum                  Clinopodium arkansana
                         dichotomijlomm
Bidens sp.             Penthorum sedoides       Conyza canadensis
Blephilia ciliata      Populus deltoides        Dadylis glomerata *
Bromus inermis *       Salix sp.                D au cus carota *
Bromus japonicus *     Setaria pumila *         Dianthus armeria *
Calystegia sepium      Sida spinosa *           Dicanthelium sp.
Carex annedens         Thlaspi arvense *        Echinochloa muricata
Carex bicknellii       Verbascum thapsus *      Eleocharis compressa
Carex brevior                                   Eleocharis
                                                  erythropoda
Carex crawei                                    Erechtites
                                                hieradfolia
Carex granularis                                Erigeron annuus
Carex gravida                                   Erigeron
                                                philadelphicus
Carex molesta                                   Eupatorium altissimum
Carex pellita                                   Eupatorium serotinum
Carex vulpinoidea                               Festuca pratensis *
Celtis ocddentalis                              Fragaria virginiana
Cichorium intybus *                             Geum ladniatum
Cirsium discolor                                Hibiscus trionum *
Cirsium vulgare *                               Juncus dudleyi
Comandra umbellata                              Juncus tenuis
Convolvulus                                     Lycopus americana
  arvensis
Coreopsis tripteris                             Medicago lupulina *
Crataegus                                       Oenothera biennis
  crus-galli
Crataegus mollis                                Oxalis stricta
Crataegus sp.                                   Panicum sp.
Cuscuta sp.                                     Panicum virgatum
Dalea candida                                   Penstemon digitalis
Dalea purpurea                                  Phleum pratense *
Desmanthus                                      Phyla lanceolata
  illinoensis
Desmodium canadense                             Plantago lanceolata *
Dichanthelium                                   Plantago rugelii
  acuminatum var.
  fasdculatum
Dichanthelium                                   Poa compressa *
  oligosanthes
Dichanthelium                                   Poa pratensis *
  villosissimum
Dipsacus fullonum *                             Poten tilla norvegica
Elaeagnus                                       Pycnanthemum
  umbellata *                                     virginianum
Eleocharis sp. 1                                Ranunculus abortivus
Eleocharis sp. 2                                Ratibida pinnata
Elymus canadensis                               Rudbeckia fulgida
Ely mus repens *                                Rudbeckia hirta
Elymus virginicus                               Rumex crispus *
Equisetum arvense                               Schizachyrium
                                                  scoparium
Equisetum hyemale                               Setaria faberi
  affine
Equisetum                                       Solanum ptycanthum
  laevigatum
Eragrostis                                      Solidago canadensis
  pectinacea
Eragrostis sp.                                  Solidago riddellii
Eriochloa villosa *                             Sorghastrum nutans
Eryngium                                        Sporobolus
  yuccifolium                                     clandestinus
Euphorbia corollata                             Sporobolus
                                                 heterolepis
Euthamia                                        Symphyotrichum
  graminifolia                                    pilosum
Fraxinus                                        Taraxacum
  pennsylvanica                                   officinale *
Galium obtusum                                  Trifolium hybndum *
Geum canadense                                  Trifolium pratense *
Glycine max *                                   Trifolium repens *
Helianthus                                      Verbena hastata
  grosseserratus
Helianthus                                      Veronica peregrina
  pauciforus
Helianthus sp.
Heliopsis
  helianthoides
Hordeum jubatum
Hypericum punctatum
Hypericum
  sphaerocarpum
Ipomoea hederucea *
Juncus sp.
Juncus torreyi
Koeleria macrantha
Kummerowia
  stipulacea *
Lactuca canadensis
Lactuca serriola *
Lactuca sp.
Leersia oryzoides
Leucanthemum
  vulgare *
Leucospora
  multifida
Liatris
  pycnostachya
Liatris sp.
Liparis liliifolia
Lobelia spicata
Lotus comiculatus *
Lycopus unijlorus
Lysimachia
  lanceolata
Lysimachia
  nummularia *
Lythrum alatum
Maclura pomifera *
Maianthemum
  stellatum
Malus ioensis
Medicago sativa *
Melilotus
  offidnalis subsp.
  alba *
Melilotus
  offidnalis *
Monarda fistulosa
Morns alba *
Packera plattensis
Parthenium
  integrifolium
Pastinaca sativa *
Penstemon pallidus
Physalis longifolia
Physalis sp.
Physostegia
  virginiana
Polygonum
  hydropiper
Polygonum
  ramosissimum
Polygonum sp.
Potentilla simplex
Pmnella vulgaris
Pmnus serotina
Pycnanthemum sp.
Rhamnus
  cathartica *
Rosa Carolina
Rosa multiflora *
Rosa setigera
Rudbeckia
  subtomentosa
Salix exigua
Sanicula canadensis
Sdrpus atrovirens
Sdrpus pendu lus
Sdrpus sp.
Scutellaria
  galericulata
Scutellaria sp.
Silphium
  integrifolium
Silphium ladniatum
Silphium
  perfoliatum
Silphium
  terebinthinaceum
Sisyrinchium
  albidum
Solanum
  carolinense *
Solanum sp.
Solidago gigantea
Solidago rigida
Solidago sp.
Stellaria media *
Stellaria sp.
Symphyotiichum
  ericoides
Symphyotrichum
  laeve
Symphyotrichum
  lanceolatum
Symphyotrichum
  novae-angliae
Symphyotrichum
  oolentangiense
Thymelaea
  passerina *
Toxicodendron
  radicans
Tradescantia
  ohiensis
Tragopogon
  pratensis *
Ulmus americana
Vemonia fasciculata
Vemonia gigantea
Veronica sp.
Viola sororia
Vitis riparia
Vitis sp.
Zizia aurea

APPENDIX 2.--Floristic summary of the aboveground community and seed
bank from transects surveyed across six different land management
histories at Midewin National Tallgrass Prairie, Will County,
Illinois. The top five most frequent species are reported

Aboveground                                    Relative
composition                  Species           Frequency   % native

Prairie remnant       Solidago canadensis         6.53      82.68
                      Poa pralensis               3.72
                      Dau cus carota              3.27
                      Agrostis gigantea           2.74
                      Andropogon gerardii         2.58
                      Symphyotrichum pilosum      2.58
                      Bromus inermis              2.58
Prairie restoration   Solidago canadensis         8.42      74.34
                      Ambrosia artemisifolia      5.77
                      Rudbeckia hirta             5.68
                      Poa pratensis               4.3
                      D au cus carota             4.12
Old field             Poa pratensis              10.08      67.68
                      Bromus inermis              8.64
                      Daucus carota               7.53
                      Ambrosia artemisifolia      3.88
                      Solidago canadensis         3.77
Active pasture        Bromus inermis             12.04      40
                      Poa pratensis              11.48
                      Trifolium pratense          9.52
                      Daucus carota               8.26
                      Phleum pratense             7
New pasture           Poa pratensis              15.75      37.84
                      Agrostis gigantea          11.81
                      Daucus carota              10.87
                      Trifolium repens            9.45
                      Ambrosia artemisifolia      9.13
Old field             Poa pratensis              10.08      67.68
                      Promus inermis              8.64
                      Dau cus carota              7.53
                      Ambrosia artemisifolia      3.88
                      Solidago canadensis         3.77
Crop field            Glycine max                43.48      36.84
                      Trifolium pratense         10.43
                      Chenopodium album           6.96
                      A bu tilon theophrasti      6.52
                      Ambrosia artemisifolia      4.78
                      Ambrosia trifida            4.78

Aboveground                                                   % weedy
composition                  Species           % non-native   species

Prairie remnant       Solidago canadensis         17.32        51.97
                      Poa pralensis
                      Dau cus carota
                      Agrostis gigantea
                      Andropogon gerardii
                      Symphyotrichum pilosum
                      Bromus inermis
Prairie restoration   Solidago canadensis         25.66        59.29
                      Ambrosia artemisifolia
                      Rudbeckia hirta
                      Poa pratensis
                      D au cus carota
Old field             Poa pratensis               32.32        71.72
                      Bromus inermis
                      Daucus carota
                      Ambrosia artemisifolia
                      Solidago canadensis
Active pasture        Bromus inermis              60            0.93
                      Poa pratensis
                      Trifolium pratense
                      Daucus carota
                      Phleum pratense
New pasture           Poa pratensis               62.16        91.89
                      Agrostis gigantea
                      Daucus carota
                      Trifolium repens
                      Ambrosia artemisifolia
Old field             Poa pratensis               32.32        71.72
                      Promus inermis
                      Dau cus carota
                      Ambrosia artemisifolia
                      Solidago canadensis
Crop field            Glycine max                 63.16        94.74
                      Trifolium pratense
                      Chenopodium album
                      A bu tilon theophrasti
                      Ambrosia artemisifolia
                      Ambrosia trifida

Aboveground                                     Total     Graminoid
composition                  Species           richness   richness

Prairie remnant       Solidago canadensis        127         27
                      Poa pralensis
                      Dau cus carota
                      Agrostis gigantea
                      Andropogon gerardii
                      Symphyotrichum pilosum
                      Bromus inermis
Prairie restoration   Solidago canadensis        113         24
                      Ambrosia artemisifolia
                      Rudbeckia hirta
                      Poa pratensis
                      D au cus carota
Old field             Poa pratensis               99         25
                      Bromus inermis
                      Daucus carota
                      Ambrosia artemisifolia
                      Solidago canadensis
Active pasture        Bromus inermis              45          8
                      Poa pratensis
                      Trifolium pratense
                      Daucus carota
                      Phleum pratense
New pasture           Poa pratensis               37          5
                      Agrostis gigantea
                      Daucus carota
                      Trifolium repens
                      Ambrosia artemisifolia
Old field             Poa pratensis               99         25
                      Promus inermis
                      Dau cus carota
                      Ambrosia artemisifolia
                      Solidago canadensis
Crop field            Glycine max                 19          1
                      Trifolium pratense
                      Chenopodium album
                      A bu tilon theophrasti
                      Ambrosia artemisifolia
                      Ambrosia trifida

Aboveground                                      Forb     Woody species
composition                  Species           richness     richness

Prairie remnant       Solidago canadensis         87           13
                      Poa pralensis
                      Dau cus carota
                      Agrostis gigantea
                      Andropogon gerardii
                      Symphyotrichum pilosum
                      Bromus inermis
Prairie restoration   Solidago canadensis         86            3
                      Ambrosia artemisifolia
                      Rudbeckia hirta
                      Poa pratensis
                      D au cus carota
Old field             Poa pratensis               67            7
                      Bromus inermis
                      Daucus carota
                      Ambrosia artemisifolia
                      Solidago canadensis
Active pasture        Bromus inermis              32            5
                      Poa pratensis
                      Trifolium pratense
                      Daucus carota
                      Phleum pratense
New pasture           Poa pratensis               27            5
                      Agrostis gigantea
                      Daucus carota
                      Trifolium repens
                      Ambrosia artemisifolia
Old field             Poa pratensis               67            7
                      Promus inermis
                      Dau cus carota
                      Ambrosia artemisifolia
                      Solidago canadensis
Crop field            Glycine max                 18            0
                      Trifolium pratense
                      Chenopodium album
                      A bu tilon theophrasti
                      Ambrosia artemisifolia
                      Ambrosia trifida

Seed bank                                      Relative
composition           Species                  Frequency   % native

Prairie remnant       Symphyotrichum pilosum     14.74      78.26
                      Solidago canadensis         8.95
                      Eupatarium altissimum       7.89
                      Juncus interior             6.84
                      Poa compressa               4.74
Prairie restoration   Mollugo verticillata       18.32      59.65
                      Setaria faberi             14.06
                      Veronica peregrina         10.65
                      Eupatorium serotinium       7.24
                      Symphyotrichum pilosum      7.1
Old field             Eupatorium serotinium      22.92      64.1
                      Daucus carota               9.49
                      Poa compressa               6.32
                      Carex sp.                   5.93
                      Oxalis stricta              5.93
                      Agrostis gigantea           4.35
                      Ijmcospora multifida        4.35
Active pasture        Oxalis stricta             17.35      46.34
                      Poa compressa               9.18
                      Digitaria sanguinalis       7.14
                      Daucus carota               6.8
                      Veronica peregrina          6.8
                      Trifolium pratense          6.46
New pasture           Solanum ptycanthum         21.32      57.14
                      Daucus carota              14.34
                      Agrostis gigantea          12.87
                      Poa compressa              11.4
                      Setaria faberi              6.62
Crop field            Chenopodium album          25.23      52.38
                      Veronica peregrina         20.56
                      Oxalis stricta             10.28
                      Populus deltoides           8.41
                      Setaria faberi              7.48

Seed bank                                                     % weedy
composition           Species                  % non-native   species

Prairie remnant       Symphyotrichum pilosum      21.74        78.26
                      Solidago canadensis
                      Eupatarium altissimum
                      Juncus interior
                      Poa compressa
Prairie restoration   Mollugo verticillata        40.35        87.72
                      Setaria faberi
                      Veronica peregrina
                      Eupatorium serotinium
                      Symphyotrichum pilosum
Old field             Eupatorium serotinium       35.9         92.31
                      Daucus carota
                      Poa compressa
                      Carex sp.
                      Oxalis stricta
                      Agrostis gigantea
                      Ijmcospora multifida
Active pasture        Oxalis stricta              53.66        92.68
                      Poa compressa
                      Digitaria sanguinalis
                      Daucus carota
                      Veronica peregrina
                      Trifolium pratense
New pasture           Solanum ptycanthum          42.86        96.43
                      Daucus carota
                      Agrostis gigantea
                      Poa compressa
                      Setaria faberi
Crop field            Chenopodium album           47.62        95.24
                      Veronica peregrina
                      Oxalis stricta
                      Populus deltoides
                      Setaria faberi

Seed bank                                       Total     Graminoid
composition           Species                  richness   richness

Prairie remnant       Symphyotrichum pilosum      46         13
                      Solidago canadensis
                      Eupatarium altissimum
                      Juncus interior
                      Poa compressa
Prairie restoration   Mollugo verticillata        57         14
                      Setaria faberi
                      Veronica peregrina
                      Eupatorium serotinium
                      Symphyotrichum pilosum
Old field             Eupatorium serotinium       39          9
                      Daucus carota
                      Poa compressa
                      Carex sp.
                      Oxalis stricta
                      Agrostis gigantea
                      Ijmcospora multifida
Active pasture        Oxalis stricta              41          9
                      Poa compressa
                      Digitaria sanguinalis
                      Daucus carota
                      Veronica peregrina
                      Trifolium pratense
New pasture           Solanum ptycanthum          28          5
                      Daucus carota
                      Agrostis gigantea
                      Poa compressa
                      Setaria faberi
Crop field            Chenopodium album           21          2
                      Veronica peregrina
                      Oxalis stricta
                      Populus deltoides
                      Setaria faberi

Seed bank                                        Forb     Woody species
composition           Species                  richness     richness

Prairie remnant       Symphyotrichum pilosum      33            0
                      Solidago canadensis
                      Eupatarium altissimum
                      Juncus interior
                      Poa compressa
Prairie restoration   Mollugo verticillata        42            1
                      Setaria faberi
                      Veronica peregrina
                      Eupatorium serotinium
                      Symphyotrichum pilosum
Old field             Eupatorium serotinium       29            1
                      Daucus carota
                      Poa compressa
                      Carex sp.
                      Oxalis stricta
                      Agrostis gigantea
                      Ijmcospora multifida
Active pasture        Oxalis stricta              31            1
                      Poa compressa
                      Digitaria sanguinalis
                      Daucus carota
                      Veronica peregrina
                      Trifolium pratense
New pasture           Solanum ptycanthum          22            1
                      Daucus carota
                      Agrostis gigantea
                      Poa compressa
                      Setaria faberi
Crop field            Chenopodium album           18            1
                      Veronica peregrina
                      Oxalis stricta
                      Populus deltoides
                      Setaria faberi


JASON J. ZYLKA (1)

Illinois Natural History Survey, 1816 South Oak Street, Champaign 61820 Department of Natural Resources and Environmental Sciences, University of Illinois, W-503 Turner Hall 1102 South Goodwin Avenue, Urbana 61801

CHRISTOPHER J. WHELAN

Illinois Natural History Survey, 1816 South Oak Street, Champaign 61820 Department of Biological Sciences, University of Illinois at Chicago, 845 West Taylor Street, Chicago 60601

AND

BRENDA MOLANO-FLORES (2)

Illinois Natural History Survey, 1816 South Oak Street, Champaign 61820

(1) Current address: Ecologist/Restoration Ecology, US Army Corps of Engineers, Chicago District, 231 S. LaSalle Street, Suite 1500, Chicago, Illinois 60604; e-mail: jason.zylka@usace.army.mil

(2) Corresponding author: Telephone: 217-265-8167; Fax: 217-244-0802; e-mail: molanol@illinois.edu
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Author:Zylka, Jason J.; Whelan, Christopher J.; Molano-Flores, Brenda
Publication:The American Midland Naturalist
Geographic Code:1U3IL
Date:Jul 1, 2016
Words:8741
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