Similarity Of Plant Communities Research Articles

Landscape connection and patch complexity explain plant community similarity in sandy grasslands better than habitat amount and landscape heterogeneity via network analysis

Landscape connection and patch complexity explain plant community similarity in sandy grasslands better than habitat amount and landscape heterogeneity via network analysis

Temporal changes in boreal vegetation under 70 years of conservation

Biodiversity conservation through protected areas (PAs) is often based on the idea that biodiversity is relatively static. This assumption is increasingly being challenged as species and communities shift their distributions in response to changing environmental conditions. Empirical evidence on the performance of PAs over decades is still sparse or lacking from several environments, although it is needed to understand species dynamics, support modelling of PA performance, assist PA management and ultimately, to achieve global biodiversity conservation goals. In 2021, we resurveyed vegetation of five boreal habitat types (heath forests, paludified forests, sun-exposed sites, mires and eulittoral sites) in Rokua National Park in Finland, where one of the conservation targets is to preserve the flora characteristic of the area. The study sites were originally surveyed in 1945-49, just before the National Park was established. Study sites have also remained free from the disturbances (forest fires and reindeer grazing) typical of boreal regions. We show that the compositional similarity of plant communities between habitat types has increased over time and is associated with the increase of forest species in several habitat types and the loss of many habitat-specific species. Drivers of change were most often linked to ongoing succession (understory closure) and changes in moisture conditions. Our results suggest that without natural disturbance or appropriate management efforts, the original conservation targets may be compromised over the decades. Our study demonstrates that resurvey of historical vegetation data can be effectively used to estimate long-term PA performance, helping to fill in missing temporal evidence.

SPATIAL DISTRIBUTION OF INVASIVE PLANTS IN BANDUNG, WEST JAVA, INDONESIA

The urban area is a source of invasive plants that enter through human activities such as agriculture and land-use conversion. Studying the invasive plant in urban areas is essential to understanding the city’s ecosystem health condition. Therefore, this study aims to inventory invasive plants, map their distribution, and explain the relationship between land use with the community diversity and species richness of invasive plants in Bandung. The vegetation analysis was performed using line-transect in 22 study sites distributed using a systematic random sampling method in Bandung to observe the plant species composition. The study plots were placed based on the land-use type. The species name, individual number, frequency, and sampling site locations were noted and analyzed to calculate the important value index (IVI) and the invasive species distribution pattern using the principal component analysis (PCA). The dominant invasive species was spatially mapped. Six types of land use were used in this study, i.e., settlements, street green lanes, gardens, paddy fields, urban parks, and urban forests. There were 187 species found in Bandung, which can be categorized into alien invasive species (39%), invasive native plants (25%), non-invasive alien species (18%), non-invasive native species (15%), and unidentified plants (3%). The most common invasive plants found were Eleusine indica (IVI=10.50%), Trimezia martinicensis (IVI=7.22%), and Cyperus rotundus (IVI=6.74%). Based on the plant community similarity index, the study area with the highest similarities were paddy fields with gardens (50.5%), settlements with road lanes (44.4%), urban parks with road lanes (26.2%), and urban forests with road lane (17.5%). PCA showed Swietenia macrophylla as the most common invasive plant found in urban forests, urban parks, and road lanes, with air humidity as the most influencing environmental factor. Trimezia martinicensis is the most common species in the settlement area affected by high air humidity. Bidens pilosa is an invasive plant commonly found on paddy fields, gardens, settlements, road lanes, and urban park edges. This species can easily and rapidly reproduce with a high survival rate. The many invasive plants found in Bandung must be managed to maintain the urban ecosystem’s health.

Relationship of Plant Species Diversity and Sampling Area Under Different Grazing Intensities in the Steppe of Northern China

The relationship between sampling area of plant community and number of species contained in it has an importance in vegetation ecology. Using a nested quadrat survey, the relationship between plant species and sampling area was discussed under different grazing pressure in the steppe and the determination of minimum sampling area was calculated herein. Ten curve models were selected to fit the species-area relation of plant community in a typical steppe of northern China. The residual standard deviation, correlation index, average value of absolute deviation, and average value of absolute relative deviation were used as the evaluation indexes for model fitting. The results show that the curve equations S = B + CAZ and S = C(1-e−BA)Z have the best simulation effect. According to the simulation results, the minimum sampling areas are determined as 1.16 m2 (T0), 1.23 m2 (T7), 1.28 m2 (T10), and 1.10 m2 (T14), presenting the minimum sampling area is feasible when the second derivative is zero. Generally, sheep grazing reduced the species richness of steppe, though some of the plans flourished while some others disappeared or dismissed, but increased spatial heterogeneity, especially on a smaller scale. However, there are also variances in different area scales and grazing intensities. When the sampling area was small (< 2 m2), heavy grazing T14 increased the number of plant species per unit area, yet light grazing T8 reduced the number of plant species per unit area of steppe. When the sampling area was large (> 16 m2), grazing reduced the number of plant species per unit area in the natural steppe. Anyhow, the effect of grazing intensity on plant species fluctuated greatly when the sampling area was medium (2 m2 ∼ 16 m2). In general, the similarity of plant communities had an increasing trend with accumulated sampling area, though it varied at different grazing intensities.

Connectivity, landscape structure, and plant diversity across agricultural landscapes: novel insight into effective ecological network planning.

Natural habitats in rural and urban areas are increasingly fragmented and altered by human impacts that are limiting the animal and plant dispersal process. Fragmentation and isolation can be reversed by restoring landscape connectivity through effective Ecological Network (EN) planning. However, most of the studies analyzing the influence of connectivity and landscape structure on biodiversity are focused on animals, while the understanding of their interplaying role on plant diversity remains limited. We studied the relationships between α and β diversity pattern and landscape structure and connectivity in the nodes of an EN developed in agricultural landscapes, as a part of regional landscape planning framework in Friuli Venezia Giulia region (North-East of Italy). As an innovation, the study aims at parsing the interacting effect of landscape structure, surrounding habitats and nodes, and structural connectivity on EN plant diversity at two specific scales of investigation i.e., the habitat and the node scale. The habitat was the basic ecological unit, while the node was the basic cartographical unit for the EN mapping (multi-habitat or mono-habitat nodes). A total of 443 plant species were collected across 219 sample plots, in 14 different habitats and 87 nodes of the EN. We found that high node connectivity leads to higher species richness (α-diversity) but also increases plant community similarity (i.e., low β-diversity) at both scales. The effect of landscape structure showed differing trends depending on the habitat. In general, landscape composition of semi-natural land cover (i.e., hedgerows, watercourses) showed a positive effect on species diversity as opposed to that of the configuration of anthropogenic elements on both scales. Our results provided crucial information on the landscape processes useful to improving biodiversity conservation by EN. Our findings suggest that i) improving connectivity within ENs favors α plant diversity ii) different habitats have different sensibility to landscape structure iii) semi-natural land cover around nodes improve plant diversity; iv) planning both mono-habitat and multi-habitats nodes, increases the biodiversity conserved therein; v) nodes with more compact shapes are to be preferred.

KERAGAMAN SPESIES HERBA DAN KEMIRIPAN KOMUNITAS TUMBUHAN PADA DUA PERIODE PEMANTAUAN BERURUTAN DI AREA REKLAMASI PT ADARO INDONESIA, PROVINSI KALIMANTAN SELATAN, INDONESIA

The development of herbaceous species according to the time of monitoring at certain sample locations in the PT Adaro Indonesia reclamation area has never been published. The purpose of the study was to compare the diversity of species and the similarity of plant communities growing in certain locations in two consecutive monitoring periods. Four locations that have been revegetated were sampled. At each location, 13 measuring plots (20 m x 20 m) were made and placed systematically. In each of these plots, 2 sub-plots (5 m x 5 m) were placed in 2 angles in opposite positions. From each sub-plot data in the form of herbaceous species names and number of individuals were collected. In one location, the number of plots changed because part of this location turned out to be active mining areas. The number of remaining plots (6 plots) was considered to not affect the results. Data is processed to obtain the density of each species at a certain location (Ki), the relative density of certain species (KRi), the frequency of each species at a certain location (Fi), the relative frequency of certain species (FRi), the importance value index (IVI), the index of species diversity Shannon-Wienner (H'), and the similarity index of the Dice community (IS). The number of species varies at each sample location and shows an increase from first monitoring to second monitoring. The species diversity index also increases. Community similarity index varies, both with calculations based on the presence or absence of species and based on the IVI. Both methods of calculation can be used but it is recommended to use calculations based on IVI.Keywords: Diversity, Monitoring period, Reclamation area, Similarity

Impact of Solidago canadensis L. on Species Diversity of Plant Communities at Different Spatial Scale

It is known that invasive dominants can significantly limit the species diversity of plant communities in microplots. However, it remains unclear whether they are capable of influencing the species diversity of large areas of vegetation. We considered this issue by the example of six areas of plant communities dominated by Solidago сanadensis located in habitats of different types (Belaya River valley, Western Caucasus, 190–210 m above sea level). Within each of them, biomass samples were taken from 25 plots of 0.25 m2, which were then disassembled by species and weighed. The results of the data analysis showed that (1) S. сanadensis significantly reduces the number of accompanying species in microplots of plant communities; however, the process of displacement of these species is predominantly nonselective (random); (2) areas of communities of different sizes with a high and low degree of dominance of S. сanadensis, containing a similar total stock of biomass of accompanying species, include, on average, a similar number of such species; and (3) the species similarity of plant communities located in habitats of different types does not depend on the degree of dominance of S. сanadensis in them. It was concluded that the size of the species pools of cenoses with high and low degrees of dominance of S. сanadensis is approximately the same. Accordingly, an increase in the participation of this species in communities can directly threaten other species only if the area of these communities is relatively small.

Historical, local and landscape factors determine the success of grassland restoration for arthropods

In Europe, extensively managed grasslands have undergone large-scale declines due to intensive agriculture and abandonment. Their restoration supports arthropod biodiversity within farming systems. We investigated limiting factors for arthropod establishment during grassland restoration across a chronosequence of 52 restoration sites established by either natural regenerating or direct seeding. Our study covered 363 arthropod species of 10 orders, including detritivores, herbivores, predators and pollinators. These were sampled using pitfall traps, suction sampling and transect walks. The similarity of plant communities on restoration sites to target species rich grasslands was positively correlated with the similarity of the arthropod communities to these same grasslands. There was evidence that restoration sites located in landscapes suffering from historic large-scale loss of species rich grassland (1930–2015) had lower success in replicating the composition of arthropod communities and supported the lowest levels of species richness. The age of the restoration site was a predictor of restoration success for some trophic levels. For example, predator species richness was greatest in the oldest restoration sites. However, this was only the case were sites were either of large size or located in landscapes with the lowest historic loss of species rich grassland. Impacts of within site management also affected arthropod communities. The annual frequency of cutting negatively affected detritivores species richness, and selected against traits including herbivore monophagy. Overall arthropod species richness was positively correlated with sward height. These results emphasise the relative importance of the success with which the floral community is replicated, as well as landscape and management factors, during grassland restoration. This has implications for future agri-environmental schemes. In particular, achieving high quality within-site management that maximises establishment of the plant communities needs to be the initial focus of any restoration program.

Do shared traits create the same fates? Examining the link between morphological type and the biogeography of fungal and bacterial communities

Abstract Although it has been commonly observed that fungi and bacteria differ in their regional biogeographic patterns, it is not well understood what traits contribute to these different distributions. Here, we evaluate how morphological type (i.e. unicellular or filamentous growth form) influences the biogeography of soil fungal and bacterial communities across not only Euclidean (i.e. geographic) distances, but also across gradients of climate and edaphic factors and plant community composition. Specifically, we assessed the decay in community similarity over distance (distance-decay relationship) for microbes with unicellular and filamentous morphology in both fungi and bacteria across 40 ecologically diverse sampling sites in Minnesota, USA. Overall, we found that while distance-decay relationships were similar in fungal and bacterial communities over Euclidean distances, there were important differences among morphological groups of fungi and bacteria across gradients of environmental and plant community similarity. Specifically, the distance-decay relationship of unicellular fungi and unicellular bacteria were indistinguishable across environmental similarity. However, as plant community similarity decreased, only filamentous fungi and unicellular bacteria differed significantly in the strength of their distance-decay relationships. Like analyses of other study systems, we also found that pH explained much of the variance in community composition across microbial domains and morphological types and that plant community diversity was more closely correlated with fungal diversity than with bacterial diversity. Collectively, our results suggest that specific ecological traits such as morphological type along with microbial domain are key factors shaping the biogeography of microbial communities.

The Impact of Changes in Species Richness and Species Replacement on Patterns of Taxonomic Homogenization in the Carpathian Forest Ecosystems

The Carpathians are Eastern Europe’s largest contiguous forest ecosystem and a hotspot of biodiversity. However, not much is known about changes in species diversity in these forests. Here we investigate the long-time changes in the diversity of plant communities in the Eastern Carpathian beech forests. We also inquire about the similarity of plant communities between managed and protected forests. We conduct our analyses using not only the broad-sense measure of changes in β diversity (βsor) but also the measures that reveal whether the changes result from spatial turnover (βsim) or nestedness (βnes). Our study demonstrated that the mean species richness did not significantly change over time in both forest types. However, we found a significant decrease of species diversity in protected forests and the same trend, but on a smaller scale, in managed forests. In both forest types the decrease of species diversity was mainly caused by spatial turnover, while nestedness-related changes were relatively small. However, the direction of changes in βnes differed in managed and unmanaged forests in such a way that it reduced the decrease of species diversity in managed forests and amplified the decrease of species diversity in unmanaged forests. We discuss our findings in terms of biotic homogenization.

Effects of adding an arbuscular mycorrhizal fungi inoculum and of distance to donor sites on plant species recolonization following topsoil removal

Questions Does addition of an arbuscular mycorrhizal fungi (AMF) inoculum increase the short-term restoration success of nutrient-poor grassland (NPG) after topsoil removal? Does distance to intact remnant grassland (IRG) patches affect restoration success, and does the effect of inoculum addition depend on distance to IRGs? Location Meerdaal forest, Oud-Heverlee, Belgium. Methods In a topsoil-removed site of 8.5 ha, where 24 IRG patches (ca. 10% of the area) were kept, 48 plots (1 m2) were established at three distances (5, 10 and 20 m) from the edge of IRG patches. Half of the plots at each distance class were inoculated with a custom-made AMF inoculum, whereas the remaining plots were used as controls. We recorded plant species abundance in the plots, just before addition of the AMF inoculum and 1 yr after. We used repeated measures ANOVA to test for effects of inoculum addition, distance to IRG patches and their interaction on plant species richness, diversity and plant community similarity between IRG patches and plots. We also evaluated the response of AMF-dependent plant species, specialist species of NPG and species with specific seed dispersal adaptations. Results Adding the inoculum positively affected species richness and/or diversity of all plant species, AMF-dependent species and specialist species. It increased plant community similarity to the IRG patches. Increasing distance from IRG patches had a negative effect on richness and/or diversity of all plant species and specialist species. The positive effect of inoculum addition on richness and/or diversity of all species, AMF-dependent species and specialist species decreased with increasing distance from IRG patches to the plots, likely indicating priority effects. Conclusions The application of a custom-made AMF inoculum increased the short-term restoration success of NPG after topsoil removal. Dispersal limitation of specialist plant species of NPG, however, likely negatively affected the effect of inoculum addition. Apart from the AMF effect, the reported strongly positive short-time effect of inoculation was likely due to the high density of IRG patches at the site, and the presence of organic matter and other micro-organisms in the inoculum.

Сообщества класса Oxycocco-Sphagnetea Br.-Bl. et R. Tx. 1943 в восточноевропейских тундрах

Сообщества класса Oxycocco-Sphagnetea Br.-Bl. et R. Tx. 1943 в восточноевропейских тундрах

The effect of typhoon‐related defoliation on the ecology of gap dynamics in a subtropical rain forest of Taiwan

AbstractQuestionsHow do frequent disturbances of varying intensity affect heterogeneity of canopy openness and resulting regenerating tree diversity in subtropical rain forests? How does canopy gap pattern and regeneration time of a forest experiencing frequent but unpredictable typhoon disturbance vary over 17 yr? How is the understorey light environment influenced by canopy gaps in a forest experiencing frequent defoliation? Compared to non‐gap areas, do gaps provide unique niches reflected in different seedling communities?LocationNatural evergreen hardwood forest, northeastern Taiwan.MethodsWe examined gap characteristics, light availability and variability, and seedling diversity in both gaps and non‐gaps in a subtropical forest with frequent typhoon disturbance, and compared the results to a survey at the same site conducted in 1995 following six typhoons in 1994.ResultsGaps were smaller and covered a much smaller proportion of the forest in the 2012 survey (mean gap size 10 m2, 3.3% of the forest) than the 1995 survey (33 m2 and 10%). Canopy regeneration times estimated from the 2012 survey (200–400 yr) were much longer than those based on the 1995 survey (50–175 yr). Neither light availability nor variability differed between gaps and non‐gaps, so gaps ostensibly did not provide a unique niche space. There were no seedling species occurring exclusively in gaps, and very high plant community similarity (&gt;90%) between gaps and non‐gaps.ConclusionsIn ecosystems with small canopy gaps resulting from frequent disturbance, gaps play a neutral role in understorey light environment and thus provide no unique niches and play a neutral role in plant diversity. Our study also suggests that measures of gap area, occurrence and forest turnover should be taken multiple times, during years with varying background disturbance rates.

Ecological effects of roads on the plant diversity of coastal wetland in the Yellow River Delta.

The 26 sample sites in 7 study plots adjacent to asphalt road and earth road in coastal wetland in the Yellow River Delta were selected to quantify plant diversity using quadrat sampling method in plant bloom phase of July and August 2012. The indice of β T and Jaccard's coefficient were applied to evaluate the species diversity. The results showed that the plant diversities and alien plants were high in the range of 0–20 m to the road verge. There were more exotics and halophytes in plots of asphalt roadside than that of earth roadside. However, proportion of halophytes in habitats of asphalt roadsides was lower than that of earth roadside. By comparing β-diversity, there were more common species in the asphalt roadsides than that in the earth roadsides. The similarity of plant communities in studied plots of asphalt roadsides and earth roadsides increased with increasing the distance to road verge. The effect range of roads for plant diversity in study region was about 20 m to road verge. Our results indicate that the construction and maintenance of roads in wetland could increase the plant species diversities of communities and risk of alien species invasion.

Plant Community Recovery following Restoration in Temporally Variable Riparian Wetlands

Abstract Wetlands historically provided many ecosystem servicesbut most have been lost or degraded through land conver-sion. Recent appreciation for wetland values and increas-ing ecotourism in the Central Platte River Valley (U.S.A.)has promoted restoration of wet meadow systems, al-though recovery patterns are not well known. We quanti-fied plant community structure in sloughs (deeper habitats)and adjacent margins (slightly higher elevation) of six wet-land sites, restored for 1–7 years at the onset of a 3-yearstudy, and three natural wetlands to assess recovery dy-namics. Plant community metrics recovered differentiallybetween habitats. Within restored margins, richness anddiversity showed aweak quadraticresponsewith time sincerestoration, indicating that both indexes overshoot naturallevels shortly following restoration. Within sloughs, rich-ness and diversity showed no change with time, suggestingthat recovery occurs more quickly in these deeper, moisterhabitats. Percent similarity of plant communities in resto-rations and natural wetlands increased linearly over time.However, ordinations of plant community compositionshowed that recovery was strongly influenced by site-spe-cific hydrology and that recovery may not be a linear tra-jectory toward natural systems. The analysis andinterpretation of plant community dynamics revealed sev-eral challenges to restoration assessment, including therole of interannual variability in precipitation, limitationsto hydrologic recovery, and temporal variability in plantcommunity structure in natural systems that resulted in‘‘moving targets’’ for recovery comparisons. Temporal var-iability in climate must be considered when assessing res-toration success in systems where plant communitystructure is responsive to variable moisture regimes.Key words: assessment, Platte River, slough, temporalvariability, vegetation, wet meadow.IntroductionWorldwide, 53% of wetlands have been lost (Mitsch G U.S. Fish and Wildlife Service 1997). The severedegradation of wetlands in the PRV is of particular con-cern because this region is extensively used by migratorybirds on the central flyway to acquire energy and nutrientsessential for migration and reproduction (U.S. Fish andWildlife Service 1997). Seven to nine million individuals of300 bird species, including the federally endangered Inte-rior Least Tern (Sterna antillarum) and Whooping Crane(Grus americana),migrate annually alongthis route(Krapuet al. 1984; Currier et al. 1985; Austin & Richert 2001).Heightened awareness of the wetland services and theextent of loss and degradation of wetland habitats hasresulted in increased efforts to protect remaining systemsand spawned widespread restoration efforts. Followingthe removal of anthropogenic disturbance (e.g., ceasingcrop production), recovery of some ecosystem aspectsoccurs through natural succession (Dormaar & Smoliak1985; Burke et al. 1995; Ihori et al. 1995). However, natu-ral recovery often requires extensive time. Therefore,restoration aims to catalyze natural recovery processesthrough habitat manipulations (e.g., returning hydrology)(Wilcox et al. 2006), reintroduction of historic plant spe-cies (e.g., seeding) (Reinartz & Warne 1993), and/or man-agement (e.g., prescribed fire) (Clark & Wilson 2001).Plants are often the focus of wetland restorations (e.g.,Willard et al. 1990; Reinartz & Warne 1993; Galatowitsch& van der Valk 1996a) because vegetation is tightly cou-pled to wetland function (Mitsch & Gosselink 2000).Although restoration is a labor-intensive process in thePRV, evaluations of these restorations have been limitedin frequency, duration, and scope (but see Currier 1994;Whitney 1997; Currier 1998).

Morphological variability of Carex spicata Huds. utricles among plant communities

Differentiation in the size and number of seeds among populations or particular individuals of a given species may depend on genetic features and environmental conditions. The objective of our study was to answer two questions: whether any differences exist in the size and shape of utricles among Carex spicata populations growing in several plant communities and whether the hypothesized differences remain constant in ‘common garden’ conditions (i.e. if the sedges grown in different plant communities are evolving distinctly separate ecotypes). We studied utricle morphological traits (projected area, width, length, W/ L ratio and projected perimeter) and number of utricles per spike collected from plants grown in five different plant communities (natural sites) and from plants transferred to common garden conditions. C. spicata utricles showed significant variability of morphological traits that depended on the plant community of origin. Among five plant communities, the largest utricles were found in Agropyron repens–Urtica dioica and Convolvulo arvensis–Agropyretum repentis communities, while the smallest ones were in plants from the Lolio-Plantaginetum community. The similarity of the analyzed populations regarding sedge utricle traits corresponded to the similarity of plant communities where the populations had grown. Moreover, the differences in utricle traits collected from natural conditions remained stable in common garden conditions. This indicated that differences in traits among utricles had a physiological dependence on different biotope conditions or different interspecific interactions prevailing in the particular plant communities. The relationship between the similarities in the diaspores of the populations studied and the similarities in the ecological conditions of the communities may also indicate that the variability of utricles is important for evolution and adaptation. The results support the hypothesis that C. spicata populations in different communities are producing separate ecotypes, i.e. specific species forms with genetically fixed traits adapted to narrowly determined habitat conditions.

The scale-dependent importance of habitat factors and dispersal limitation in structuring Great Lakes shoreline plant communities

Niche-based and neutral models of community structure posit distinct mechanisms underlying patterns in community structure; correlation between species’ distributions and habitat factors points to niche assembly while spatial pattern independent of habitat suggests neutral assembly via dispersal limitation. The challenge is to disentangle the relative contributions when both processes are operating, and to determine the scales at which each is important. We sampled shoreline plant communities on an island in Lake Michigan, varying the extent and the grain of sampling, and used both distance-based correlation methods and variance partitioning to quantify the proportion of the variation in plant species composition that was attributable to habitat factors and to spatial configuration independent of habitat. Our results were highly scale dependent. We found no distance decay of plant community similarity at the island scale (1−33 km). All of the explained variation (32%) in species composition among samples at this scale was attributed to habitat factors. However, at a site intensively sampled at a smaller scale (5−1,200 m), similarity of species composition did decay with distance. Using a coarse sampling grain (transects), habitat factors explained 40% of the variation, but the purely spatial component explained a comparable 22%. Analyzing plots within transects revealed variation in species composition that was still jointly determined by habitat and spatial factors (18 and 11% of the variance, respectively). For both grain sizes, most of the habitat component was spatially structured, reflecting an abrupt alongshore transition from sandy dunes to cobble beach. Space per se explained more variation in species composition at a second site where the habitat transition was more gradual; here, habitat acted as a less selective filter, allowing the signal of dispersal limitation to be detected more readily. We conclude that both adaptation to specific habitat factors and habitat-independent spatial position indicative of dispersal limitation determine plant species composition in this system. Our results support the prediction that dispersal limitation—a potentially, but not necessarily, neutral driver—is relatively more important at smaller scales.

Contrasting success in the restoration of plant and phytophagous beetle assemblages of species-rich mesotrophic grasslands

Over the last 60 years changes to the management of species-rich mesotrophic grasslands have resulted in the large-scale loss and degradation of this habitat across Europe. Restoration of such grasslands on agriculturally improved pastures provides a potentially valuable approach to the conservation of these threatened areas. Over a four-year period a replicated block design was used to test the effects of seed addition (green hay spreading and brush harvest collection) and soil disturbance on the restoration of phytophagous beetle and plant communities. Patterns of increasing restoration success, particularly where hay spreading and soil disturbance were used in combination, were identified for the phytophagous beetles. In the case of the plants, however, initial differences in restoration success in response to these same treatments were not followed by subsequent temporal changes in plant community similarity to target mesotrophic grassland. It is possible that the long-term consequences of the management treatments would not be the establishment of beetle and plant communities characteristic of the targets for restoration. Restoration management to enhance plant establishment using hay spreading and soil disturbance techniques would, however, still increase community similarity in both taxa to that of species-rich mesotrophic grasslands, and so raise their conservation value.

Grazing and Grazing Exclusion Effects on New Mexico Shortgrass Prairie

Vegetative differences and changes were evaluated over a 6-year period (1999–2004) on adjoining conservatively grazed and grazing-excluded (22 years) shortgrass rangelands in northwestern New Mexico. Autumn total perennial grass and blue grama (Bouteloua gracilis [Willd. ex Kunth] Lag. Griffiths) standing crop did not differ on grazed and grazing-excluded areas when data were averaged across years. There were no long-term differences in vegetation basal cover or composition between the grazed and grazing-excluded areas. Plant community similarity values between the grazed and grazing-excluded areas were 80% and 93% during the first 2 years (1999–2000) and last 2 years (2003–2004) of study, respectively. Climatic conditions had more impact on vegetation composition of the 2 areas than livestock grazing. Similarity values between 1999–2000 and 2003–2004 periods were 52% and 64% for the grazed and grazing-excluded plant communities, respectively. At the beginning of our study, blue grama productivity was depressed on the grazed area compared to the exclosure, but after 3 years of conservative winter grazing, it was similar on the 2 areas. Our study indicates there is no benefit to blue grama rangelands from long-term rest from the standpoint of vegetation composition.

Grazing and Grazing Exclusion Effects on New Mexico Shortgrass Prairie

Vegetative differences and changes were evaluated over a 6-year period (1999-2004) on adjoining conservatively grazed and grazing-excluded (22 years) shortgrass rangelands in northwestern New Mexico. Autumn total perennial grass and blue grama (Bouteloua gracilis [Willd. ex Kunth] Lag. Griffiths) standing crop did not differ on grazed and grazing-excluded areas when data were averaged across years. There were no long-term differences in vegetation basal cover or composition between the grazed and grazing-excluded areas. Plant community similarity values between the grazed and grazing-excluded areas were 80% and 93% during the first 2 years (1999-2000) and last 2 years (2003-2004) of study, respectively. Climatic conditions had more impact on vegetation composition of the 2 areas than livestock grazing. Similarity values between 1999-2000 and 2003-2004 periods were 52% and 64% for the grazed and grazing-excluded plant communities, respectively. At the beginning of our study, blue grama productivity was depressed on the grazed area compared to the exclosure, but after 3 years of conservative winter grazing, it was similar on the 2 areas. Our study indicates there is no benefit to blue grama rangelands from long-term rest from the standpoint of vegetation composition.