Species Diversity In Grasslands Research Articles

Impacts of Grazing on Vegetation and Soil Physicochemical Properties in Northern Yinshan Mountain Grasslands

The grasslands at the northern foot of the Yinshan Mountains are an integral component of the northern grassland ecosystem in China. The ecosystem in this region has low stability and poor resistance to disturbance. In this study, experiments were conducted to evaluate the possible changes in vegetation community structure and soil physicochemical properties due to overgrazing in the grasslands. Completely randomized group experiments were designed with grazing intensity as the single-factor study was conducted using natural grassland located in Xilamuren (in Inner Mongolia, northern China) as the study area. Three blocks were created, each having four plots of different grazing intensities and each block having an area of 100 m × 100 m. The experiments were conducted to evaluate the possible variances both in the structure of the vegetation community and the soil physicochemical properties resulting from overgrazing in the grasslands at the northern foot of Yinshan Mountain. The results were as follows: The importance values of dominant species, such as Heteropappus altaicus and Artimisia gmelinii, exhibited varying degrees of change with an increase in the grazing intensity. The surface vegetation cover decreased significantly with an increase in the grazing intensity. The increasing grazing intensity led to a significant increase in the content of very coarse sand grains in the soil. Severe grazing increased the exposed surface area, intensified the effects of blowing wind and scouring action of water, and led to the coarsening of topsoil particles. At 0–5 cm depth, the bulk density of soil exhibited an increasing tendency with an increase in the grazing intensity. The organic matter content of the soil in the heavily grazed plots decreased by 11.74%, 11.00%, and 14.08%, respectively, when compared to that in the 0–40 cm soil layer with no grazing, light grazing, and moderate grazing. The results emphasized the importance of managing grazing intensity for soil and vegetation restoration. Thus, the effects of short-term grazing (for example, 5 years) on vegetation community composition and species diversity may be less pronounced. This study contributes to our understanding of pasture management and the restoration of grassland species diversity.

Impact of precipitation and grazing on recovery of plant vegetation in temperate grasslands

AbstractGrasslands support a rich diversity that plays a pivotal role in ecological balance, carbon sequestration, and climate regulation. Grassland ecosystems are facing a loss of biodiversity and a decline in soil function due to precipitation variations caused by climate change. However, variations in grassland species diversity are not clearly known, especially under the combined effects of precipitation and grazing. Based on a 5‐year split‐plot experiment with two grazing regimes (i.e., moderate grazing and grazing prohibition) along with three precipitation controls (ambient precipitation and ±50% precipitation) in Inner Mongolian grasslands, we researched the response of precipitation variability and grazing prohibition to vegetation diversity indices and investigated the response of vegetation community composition and biomass to these factors. Five years results showed that increasing precipitation resulted in a significant increase in the coverage of perennial forbs, annual and biennial plants, and Gramineae. Grazing prohibition and increased precipitation significantly increased biomass and species richness compared to all other treatment combinations. Interestingly, grazing exclusion significantly reduced the percentage of Amaryllidaceae, especially in the presence of altered precipitation. The vegetation community composition of a typical grassland was correlated with soil volumetric water content (VWC), bulk density (SBD) and pH, soil organic carbon (SOC), and total nitrogen (TN). VWC, SBD, and TN were found to be the most significant factors affecting vegetation diversity under grazing. Partial canonical ordination revealed that soil moisture, soil bulk density, and SOC had the most significant correlation with vegetation diversity under both grazing prohibition and increased precipitation treatment conditions. These results suggested that alterations in precipitation can change the species composition and ecosystem function of plant communities, leading to a close relationship between species diversity and soil properties. Our results underline the importance of species diversity for soil characteristics and environmental factors in a typical Eurasian steppe ecosystem.

Community structure and plant diversity under different degrees of restored grassland in mining areas of the Qilian Mountains, Northwestern China

Background: Mining activities are known to exert significant effects on the structure and function of grassland ecosystems. However, the role of mining grasslands restoration in altering the plant community and soil quality remains poorly understood, especially in alpine regions. Here, we investigated species diversity in grasslands with dynamic changes and different restoration levels in the Tianzhu alpine mining area locating in the Qilian Mountains.Methods: The plant community structure and species composition of the grasslands with different restoration levels were analyzed by the sample method. We used five different restoration levels: very low recovered degree (VLRD), low recovered degree (LRD), medium recovered degree (MRD), and high recovered degree (HRD), and selected natural grassland (NGL, CK) as the control.Results: Plant community structure and species composition were significantly higher than those under the VLRD in the Tianzhu alpine mining area (p < 0.05), with HRD > MRD > LRD > VLRD. There were 11 families, 18 genera, and 17 species of plants, mainly in the families of Leguminosae, Asteraceae, Gramineae, Rosaceae, and Salicaceae; among them, Salicaceae and Gramineae played a decisive role in the stability of the community. The ecotype community showed that perennial herbaceous plants were the most dominant, with annual herbaceous plants being the least dominant, and no tree and shrub layers were observed; the dominance index was the highest in VLRD at 0.32, the richness index was the highest in HRD at 2.73, the diversity of HRD was higher at 1.93, soil pH and EC showed a decreasing trend, and SMC, SOC, TN, NO3-N, NH4-N, AN, TP, and AP content showed an increasing trend with the increase of grassland restoration.Conclusion: In summary, with the increase of restored grassland in the Tianzhu alpine mining area, plant diversity gradually increased and plant community structure gradually diversified, which was close to the plant diversity of NGL. The protection of partially VLRD and LRD grasslands in the mining area should be emphasized, and the mine grassland should be used rationally and scientifically restored.

Response of Temperate Leymus chinensis Meadow Steppe Plant Community Composition, Biomass Allocation, and Species Diversity to Nitrogen and Phosphorus Addition

Studies on the impacts of fertilization on plant production and species diversity are crucial for better maintaining the stability of grassland ecosystems and restoring degraded grasslands. Using a controlled fertilization experimental platform in a temperate Leymus chinensis meadow steppe ecosystem, the effects of different levels of nitrogen (N) and phosphorus (P) addition on plant community structure, biomass allocation, diversity, and the correlation relationship were explored. The major results were as follows: (1) The structural composition of the plant community changed after different levels of N and P addition; the dominance ratio and biomass of Poaceae plants increased gradually with increasing N and P addition levels. (2) The addition of N and P increased the height, density and coverage of the plant community, the biomass of the dominant L. chinensis and plant community and the total productivity of grassland, and reduced the root–shoot ratio of grassland biomass. For example, plant community biomass, gramineous plant biomass and grassland total productivity increased by 84.46–204.08%, 162.64–424.20%, and 38.12–46.44%, respectively, after N and P addition. (3) The community richness, diversity, and evenness indices decreased overall and showed binomial regression after N and P addition; the functional group of Poaceae plants was highly significantly negatively correlated with species diversity indices and was highly significantly positively correlated with the aboveground biomass of L. chinensis and community; Leguminosae plants and Ranunculaceae plants were highly significantly positively correlated with Margalef and Patrick richness indices; Ranunculaceae plants were highly significantly and negatively correlated with L. chinensis biomass, community biomass, and Poaceae plants. Moderate fertilization not only improved the plant community structure and productivity but was also beneficial for maintaining the grassland species diversity and stability.

Photovoltaic panels have altered grassland plant biodiversity and soil microbial diversity.

Human concerns about fossil fuel depletion, energy security and environmental degradation have driven the rapid development of solar photovoltaic (PV) power generation. Most of the photovoltaic power generation plants are concentrated in desert, grassland and arable land, which means the change of land use type. However, there is still a gap in the research of the PV panel layout on grassland plant species diversity and ecological function. In this study, Illumina high-throughput sequencing technology was used to investigate the effects of PV panel arrangement on grassland plant species diversity and soil microbial diversity. In view of the differences in the microclimate at different sites of the PV panels, quadrates were arranged in front edge (FE), beneath the center of each panel (BP), back edge (BE), the uncovered interspace adjacent to each panel (IS) and the undisturbed grassland around the PV panels (Control), respectively. PV panels (especially FE) significantly increased the total aboveground productivity (total AGB) and plant species diversity in grasslands. FE increased precipitation accumulation and plant species diversity directly and indirectly changed the diversity of soil bacterial and fungal communities. PV panels decreased the relative abundance of Actinobacteriota, while increased the relative abundance of Proteobacteria, Acidobacteriota, and Methylomirabilota. EC, Margalef' s richness and total AGB were the main factors affecting the composition of bacterial communities, while alkaline hydrolysis nitrogen (AN) and available phosphorus (AP) were the main factors affecting the composition of fungal communities. In conclusion, the arrangement of PV panels increased the plant species diversity and soil microorganisms in grassland. This study provides important information for further understanding the impact of PV panels on grassland ecosystem function and is of great significance for maintaining grassland ecosystem function.

Drivers of species-specific contributions to the total live aboveground plant biomass in Central European semi-natural hay grasslands

Semi-natural grasslands are known to provide numerous ecosystem services, of which one of the most important is production of biomass. However, the contribution of individual plant species to the total biomass is much less well understood. This study addressed questions concerning community structure and responses of species-specific biomass (s-AGB) to gradients in soil acidity and fertility, topographical and climatic features, and disturbance regimes in mown and abandoned grasslands in the Sudetes Mountains (Central Europe). It identified pH as the most significant environmental gradient affecting turnover in s-AGB, and mowing cessation, temperature, and precipitation also had significant effects. Further, it showed high inequality in biomass among co-occurring plant species. It also showed that biomass inequality (measured by the Gini coefficient) among interacting species decreases with increasing functional diversity (Rao’s index). This study highlights that common plant species (in terms of frequency) play a major role in contributing to the total aboveground biomass (t-AGB). However, less frequent species are also significant contributors to the t-AGB. Thus, the combined contribution of infrequent species to the t-AGB should not be neglected. Our findings support the mass ratio hypothesis stating that ecosystem functions such as biomass production depend on dominant species. On the other hand, high niche differentiation ensures the coexistence of less competitive species with the dominants by the variety and complementarity of functional traits. Infrequent and non-dominant species were the core of the diversity seen in the studied grasslands. The maintenance of species diversity in grasslands should be prioritized in nature conservation policies to ensure the sustainability of ecosystem services.

How Seasonal Grazing Exclusion Affects Grassland Productivity and Plant Community Diversity

The Sanjiang Plain is famous for its concentrated distribution of natural wet grasslands. These wet grasslands are an important source of seasonal pasture or hay in the area. However, changes in community structure and ecosystem function have already occurred in wet grasslands because of overgrazing and climate change, resulting in severe grassland degradation. Exploring a reasonable grazing management strategy is crucial for improving grassland species diversity, increasing grassland productivity, and maintaining sustainable grassland utilization. We investigated the effects of five grazing management (GM) strategies (no grazing through the growing season (CK), spring grazing exclusion (Spr-GE), summer grazing exclusion (Sum-GE)), autumn grazing exclusion (Aut-GE), and grazing through the growing season (G)) on the productivity, community composition and structure of wet grasslands in the Sanjiang Plain under three grazing intensities (GI) (light (L), moderate (M), and heavy (H)). Results showed that Spr-GE and Sum-GE were beneficial in increasing total aboveground biomass (AGB), but decreased plant community diversity in Spr-GE due to increased intraspecies and interspecies competition. The exclusion of different seasonal grazings changed the composition of plant communities. At the level of functional groups and dominant species, Spr-GE had a significant effect on most functional groups and dominant species’ characteristics, while Aut-GE had little effect on most functional groups and dominant species’ characteristics. However, different functional groups and dominant species had different responses to seasonal grazing exclusion. In addition, under M, there were significantly improved grassland total AGB and PF AGB. The results indicated that Spr-GE with M may be an effective livestock-management strategy to protect grassland vegetation and community diversity, as well as to restore degraded grassland.

The role of groundwater depth in semiarid grassland restoration to increase the resilience to drought events: A lesson from Horqin Grassland, China

Grassland degradation in the semiarid area of China is often attributed to overgrazing and expansion of irrigated agriculture without the consideration of groundwater. However, falling groundwater levels in the region have caused many problems for grassland ecology. In this paper,the typical sandy grassland- the Tongliao part of Horqin grassland was selected as the study area to study the spatial distribution of normalized difference vegetation index (NDVI) and the relationship between the NDVI and groundwater depth (GD) of each grassland pixel was studied. The temporal variation of the NDVI and its correlations with precipitation were investigated. The relationship between GD and vegetation species diversity in grassland was analyzed based on the vegetation survey. The results of the relation between GD and NDVI and vegetation species showed that GD can buffer the impact of increase in drought events on the vegetation because GD affected the composition and diversity of vegetation species. As the GD increases, the mean NDVI showed a trend of increasing first and then decreasing, and basically remained unchanged when the GD was greater than 3.5 m. The species diversity of grassland decreased with increasing GD and was not related to GD when GD was greater than 3.5 ∼ 4 m. Falling groundwater levels will cause great changes in the structure of grassland; specifically, azonal vegetation will gradually die and 3.5 m may be the critical GD needed to maintain the incomplete extinction of grassland azonal vegetation in the aeolian sandy soil. Correlation analysis proved that the correlation between NDVI and precipitation was significantly enhanced when GD increased sharply from 3 m to 6 m after 1999. This research indicates that the control of grassland degradation should pay attention to controlling the groundwater exploitation to recover a reasonable groundwater level, which was found to be necessary in the support of diverse and climate resilient of vegetation.

Mowing and phosphorus affect plant diversity and soil carbon and nitrogen storage under nitrogen enrichment in the semi-arid alpine steppe

Plant diversity strongly affected the grassland productivity and soil C and N storage. Nitrogen enrichment weakens the stability of the ecosystem through decreased biodiversity. Mowing is a viable management tool for the maintenance of diversity in grasslands. However, it is unclear how plant diversity affects soil C and N storage in mowing (or phosphorus) under N enrichment in the semi-arid alpine steppe. In the present study, a 3-year trial has investigated the effects of nitrogen, mowing (or phosphorus), and their interactions on plant diversity and soil C and N storage in a semi-arid alpine steppe in Qilian mountains, northern China. We found that aboveground biomass (AGB) was significantly increased in N (nitrogen added alone) and NP (both nitrogen and phosphorus added), significantly decreased in M (mowing) across the three years (2019–2021) (P < 0.05), and significantly increased by 21.4% in the third year in MN (nitrogen added at the time of mowing). Plant diversity was significantly decreased in N and NP, but had no significant effect under M, MN, and P across the three years. We found that SOC stock was significantly decreased by 13% in the 0–10 cm soil layer in N, while increased by 6% at the 10–20 cm soil layer in MN. In contrast, NP had no significant effect on SOC stock and TN stock, while both NO3–N and AP significantly increased. M increased the relative biomass of sedge and forb, while N increased the relative biomass of grass and decreased the relative biomass of forb. Forb is positively correlated with C storage and negatively correlated with N storage, while the grass is the opposite. Therefore, the results indicated that mowing modulated the effects of N addition on diversity loss and carbon stock loss. In contrast, phosphorus is ineffective for the negative effect of nitrogen on grassland species diversity.

Methods and development trend for the measurement of plant species diversity in grasslands.

Plant species diversity is one of the critical factors for maintaining multi-function and stability of terrestrial ecosystem. We reviewed the traditional methods for measuring plant species diversity of grassland (PSDG), and then introduced the new ideas and methods used for PSDG monitoring. Traditionally, PSDG monitoring depended heavily on ground-based investigation, which usually required large amounts of time, labor, and cost, and therefore was only suitable for small scale investigation. Grassland plant species were typically small in size and highly mixed. It was difficult to identify and measure by remote sensing due to the limitation of resolution. Consequently, most studies on PSDG were based on remote-sensing retrieval or habitat simulation. Characterized with high spatial-temporal resolution, flexible and low cost, the unmanned aerial vehicle (UAV) technology was regarded as the bridge between ground-based investigation and satellite remote sensing. It could be the breakthrough for monitoring PSDG accurately at large scales. In the future, we should establish PSDG monitoring network by combining the fixed monitoring sites and dynamic monitoring sites of UAV and satellite remote sensing, and integrating UAV and automatic target recognition organically.

Assessing the Impact of Soil on Species Diversity Estimation Based on UAV Imaging Spectroscopy in a Natural Alpine Steppe

Grassland species diversity monitoring is essential to grassland resource protection and utilization. “Spectral variation hypothesis” (SVH) provides a remote sensing method for monitoring grassland species diversity at pixel scale by calculating spectral heterogeneity. However, the pixel spectrum is easily affected by soil and other background factors in natural grassland. Unmanned aerial vehicle (UAV)-based imaging spectroscopy provides the possibility of soil information removal by virtue of its high spatial and spectral resolution. In this study, UAV-imaging spectroscopy data with a spatial resolution of 0.2 m obtained in two sites of typical alpine steppe within the Sanjiangyuan National Nature Reserve were used to analyze the relationships between four spectral diversity metrics (coefficient of variation based on NDVI (CVNDVI), coefficient of variation based on multiple bands (CVMulti), minimum convex hull volume (CHV) and minimum convex hull area (CHA)) and two species diversity indices (species richness and the Shannon–Wiener index). Meanwhile, two soil removal methods (based on NDVI threshold and the linear spectral unmixing model) were used to investigate the impact of soil on species diversity estimation. The results showed that the Shannon–Wiener index had a better response to spectral diversity than species richness, and CVMulti showed the best correlation with the Shannon–Wiener index between the four spectral diversity metrics after removing soil information using the linear spectral unmixing model. It indicated that the estimation ability of spectral diversity to species diversity was significantly improved after removing the soil information. Our findings demonstrated the applicability of the spectral variation hypothesis in natural grassland, and illustrated the impact of soil on species diversity estimation.

Phytosociology, ecology and plant species diversity of grasslands within nature protection sites near Zurich (Switzerland)

Phytosociology, ecology and plant species diversity of grasslands within nature protection sites near Zurich (Switzerland)

Soil carbon and plant richness relationships differ among grassland types, disturbance history and plant functional groups

Understanding the relationship of soil carbon storage and species diversity in grasslands can provide insights into managing these ecosystems. We studied relationships among soil C and plant species richness within ~ 9700 ha of grasslands in Colorado, US. Using 141 grassland transects, we tested how soil C was related to plant species richness, grassland type, soil texture, and prairie dog presence. Soil C was significantly, positively related to plant species richness, while native perennial graminoid species richness exhibited an even stronger positive relationship. However, the relationship of soil C and plant richness was not found in all three grassland types studied, but instead was unique to the most common grassland type, mixed grass prairie, and absent from both xeric tallgrass and mesic tallgrass prairie. The presence of a single indicator species, Andropogon gerardii, showed a significant, positive relationship with soil carbon. Our best possible model explained 45% of the variance in soil C using species richness, grassland type, and their interaction. Surprisingly, soil C was negatively related to soil clay, suggesting that surface clays amplify evaporation and water runoff rather than protecting soil organic matter from decomposition. Soil C was negatively related to prairie dog presence, suggesting that prairie dogs do not enhance soil carbon sequestration; in fact, prairie dog occupied sites had significantly lower soil C, likely related to loss of topsoil from prairie dog colonies. Our results suggest that management for species richness provides the co-benefit of soil C storage, and high clay and prairie dog disturbance compromises both.

Increasing connectivity enhances habitat specialists but simplifies plant\u2013insect food webs

Strong declines of grassland species diversity in small and isolated grassland patches have been observed at local and landscape scales. Here, we study how plant–herbivore interaction webs and habitat specialisation of leafhopper communities change with the size of calcareous grassland fragments and landscape connectivity. We surveyed leafhoppers and plants on 14 small (0.1–0.6 ha) and 14 large (1.2–8.8 ha) semi-natural calcareous grassland fragments in Central Germany, differing in isolation from other calcareous grasslands and in the percentage of arable land in the surrounding landscape (from simple to complex landscapes). We quantified weighted trophic links between plants and their phytophagous leafhoppers for each grassland fragment. We found that large and well-connected grassland fragments harboured a high portion of specialist leafhopper species, which in turn yielded low interaction diversity and simple plant-leafhopper food webs. In contrast, small and well-connected fragments exhibited high levels of generalism, leading to higher interaction diversity. In conclusion, food web complexity appeared to be a poor indicator for the management of insect diversity, as it is driven by specialist species, which require high connectivity of large fragments in complex landscapes. We conclude that habitat specialists should be prioritized since generalist species associated with small fragments are also widespread in the surrounding landscape matrix.

Does the local conservation practice of cultural ecosystem services maintain plant diversity in semi-natural grasslands in Kirigamine Plateau, Japan?

Wildflower viewing is recommended as a form of ecotourism in protected areas to facilitate conservation practices; but this relationship between the conservation of attractive flowering plant species and whole plant diversity has not been quantitatively evaluated. The Kirigamine Plateau in Japan encompasses a protected area that supports high grassland species diversity. Browsing activity by the expanding sika deer populations has negatively impacted this region in recent decades, drastically decreasing blooming flower resources that attract ecotourism. The effectiveness of conserving plant diversity through the placement of deer fences by local conservation practices was evaluated, and indicator species requiring future conservation strategies were identified. Compared to outside the deer fences, the five species diversity metrics (flowering plant richness, flowering abundance, flowering functional diversity (flowering FD), plant species richness, and threatened plant species richness) were significantly higher inside the fences. Except for flowering FD, plant species richness was positively correlated with all other species diversity metrics. The important species analysis identified four species as indicators of conservation for plant diversity and flowering FD out of the top 20 indicator species. The construction of deer fences had a strong positive effect on the preservation of four diversity metrics. However, to conserve flowering FD, additional strategies need to be implemented in this area. Conservation planning based on flowering plant diversity and cultural ecosystem services is vital in reducing the loss of biodiversity in semi-natural grasslands in protected areas worldwide.

Soil moisture and a legacy of prehistoric human activities have contributed to the extraordinary plant species diversity of grasslands in the White Carpathians

The factors that determine the unique species richness and composition of some temperate grasslands are poorly known. Uniqueness of the extraordinarily species-rich grasslands in the White Carpathian mountain range (Czech Republic, Slovakia), with many disjunct occurrences of species, have been previously attributed to intermittently wet deep soils, which facilitate the co-occurrence of steppe and wet-grassland species, and Holocene continuity of open land, resulted in large species pools. Based on a detailed investigation of 23 well-preserved regularly mown grasslands differing in their vegetation composition and species richness, we tested the relative importance of the hypothetical determinants of compositional variability within semi-dry grasslands. For the first time we included measurements of seasonal moisture at different soil depths and landscape differences in the intensity of the effect of prehistoric humans. Soil moisture was measured using the frequency-domain reflectometry based Profile Probe PR2 sensor at depths of 10, 20, 30, 40 and 60 cm in the soil, repeatedly every four weeks from April to November. Soil samples were taken from the same depths in order to determine soil basicity and nutrient content. As a proxy of the intensity of the effect of prehistoric human activities, mean distances between sampled localities and the five nearest Neolithic or Aeneolithic settlements were used. The species richness was best explained by mean soil moisture, which increased towards the most species-rich grasslands, whereas the distance from prehistoric settlements had no effect. Basicity, moisture and the distance from prehistoric settlements had significant conditional effects on species composition. There was a high frequency of species of intermittently wet soils, thermophilous oak forests and forest fringes in the most valuable grasslands, which are located mostly in the south-western part of the area where the soils were moister and closer to prehistoric settlements, but the seasonal variation in moisture was not high. We conclude that coexistence of species from different habitats is dependent on regular management and high soil moisture throughout the growing season. Due to intermediate moisture conditions that are tolerated by multiple ecological groups of species, many species may locally coexist and form a species-rich grassland community of unique species composition. In addition, prehistoric human activities contributed to landscape openness and helped maintain a forest-steppe species pool during the Holocene forest optimum. Our results indicate that although this historical determinant shapes predominantly the species composition pattern, the extraordinarily species-rich spots are determined rather by abiotic factors, such as intermediate moisture and biotic interactions resulting from the type and duration of management practices.

Economic benefits from plant species diversity in intensively managed grasslands

Grasslands cover a major share of the world’s agricultural area and are important for global food security. Plant species diversity in grasslands is known to increase and stabilize biomass yields. We economically evaluate these effects, using a rich dataset from 16 intensively managed grassland sites across Europe. We extend earlier research by accounting for plant species diversity effects on both quantity and quality of yields. Consequently, we can express plant species diversity effects in terms of milk production potential yields per hectare and potential revenues thereof. Plant species diversity not only increased milk production potential yields and thus revenues, but also reduced production risks. Thus, increasing plant species diversity resulted in higher certainty equivalents, for example, the certainty equivalent rose by +29% when comparing the average mixture to the average monoculture. For risk averse decision makers, this gain in certainty equivalent was mainly due to the increase in revenues (accounting for 90%) compared to the total insurance value (accounting for 10%). Overall, we show that farmers benefit economically from plant species diversity and that even a moderate increase in this diversity contributes to more stable grassland-based production. Thus, our results are highly relevant for future sustainable intensification of grassland-based production.

Contribution of common vs. rare species to species diversity patterns in conservation corridors

Abstract Understanding how common vs. rare species contribute to species richness patterns, and are differentially affected by landscape features, is essential for effective conservation monitoring and planning. Using common vs. rare dung beetles and ants, we test how species rarity shapes richness patterns across a timber plantation mosaic with remnant natural grassland conservation corridors as a mitigation measure. We then determine how environmental and spatial factors shape assemblage composition of common and rare grassland species, and how matrix-derived species influence these patterns. For each taxon, species were ranked from common-to-rare, and from rare-to-common. This ranking gave sequences of species richness patterns for increasing numbers of species. Along each stage of these two sequences, species richness of the sub-assemblage was correlated with that of the whole assemblage. This was repeated with matrix-derived species excluded. Deconstructing the species response matrices according to species traits, variation in composition of common vs. rare grassland specialists, as well as in matrix-derived species, were related to environmental (natural environmental heterogeneity and habitat quality) and spatial factors. For both taxa, common species reflected overall species richness patterns better than rare species. Matrix-derived species reduced the contribution of rare species to species richness patterns of dung beetles. Environmental variables were relatively more important for rare species than for common species composition, especially rare ants. We found that in a fragmented landscape: 1) common species reflect overall species richness patterns better than rare species, 2) overall species richness patterns do not reflect those of rare species, 3) the relative influence of regional- and local-scale factors are determined by an organism’s scale of life function, 4) rare species are especially affected by habitat quality, 5) knowledge of ecological processes governing communities in landscape mosaics are crucial for conserving grassland species diversity within these corridors.

Plant species richness and functional groups have different effects on soil water content in a decade‐long grassland experiment

Abstract The temporal and spatial dynamics of soil water are closely interlinked with terrestrial ecosystems functioning. The interaction between plant community properties such as species composition and richness and soil water mirrors fundamental ecological processes determining above‐ground–below‐ground feedbacks. Plant–water relations and water stress have attracted considerable attention in biodiversity experiments. Yet, although soil scientific research suggests an influence of ecosystem productivity on soil hydraulic properties, temporal changes of the soil water content and soil hydraulic properties remain largely understudied in biodiversity experiments. Thus, insights on how plant diversity—productivity relationships affect soil water are lacking. Here, we determine which factors related to plant community composition (species and functional group richness, presence of plant functional groups) and soil (organic carbon concentration) affect soil water in a long‐term grassland biodiversity experiment (The Jena Experiment). Both plant species richness and the presence of particular functional groups affected soil water content, while functional group richness played no role. The effect of species richness changed from positive to negative and expanded to deeper soil with time. Shortly after establishment, increased topsoil water content was related to higher leaf area index in species‐rich plots, which enhanced shading. In later years, higher species richness increased topsoil organic carbon, likely improving soil aggregation. Improved aggregation, in turn, dried topsoils in species‐rich plots due to faster drainage of rainwater. Functional groups affected soil water distribution, likely due to plant traits affecting root water uptake depths, shading, or water‐use efficiency. For instance, topsoils in plots containing grasses were generally drier, while plots with legumes were moister. Synthesis. Our decade‐long experiment reveals that the maturation of grasslands changes the effects of plant richness from influencing soil water content through shading effects to altering soil physical characteristics in addition to modification of water uptake depth. Functional groups affected the soil water distribution by characteristic shifts of root water uptake depth, but did not enhance exploitation of the overall soil water storage. Our results reconcile previous seemingly contradictory results on the relation between grassland species diversity and soil moisture and highlight the role of vegetation composition for soil processes.

Plant, soil and microbial controls on grassland diversity restoration: a long‐term, multi‐site mesocosm experiment

Summary The success of grassland biodiversity restoration schemes is determined by many factors; as such their outcomes can be unpredictable. There is a need for improved understanding of the relative importance of below‐ground factors to restoration success, such as contrasting soil type and management intensities, as well as plant community composition and order of assembly. We carried out an 8‐year mesocosm experiment across three locations in the UK to explore the relative and interactive roles of various above‐ground and below‐ground factors in the establishment of target species, to determine general constraints on grassland restoration. Each location had a series of mesocosms with contrasting soil types and management status, which were initially sown with six grasses typical of species‐poor grasslands targeted for restoration. Over 5 years, sets of plant species were added, to test how different vegetation treatments, including early‐coloniser species and the hemiparasite Rhinanthus minor, and soil type and management, influenced the establishment of target plant species and community diversity. The addition of early‐coloniser species to model grasslands suppressed the establishment of target species, indicating a strong priority effect. Soil type was also an important factor, but effects varied considerably across locations. In the absence of early‐coloniser species, low soil nutrient availability improved establishment of target species across locations, although R. minor had no beneficial effect. Synthesis and applications. Our long‐term, multi‐site study indicates that successful restoration of species‐rich grassland is dependent primarily on priority effects, especially in the form of early‐coloniser species that suppress establishment of slow‐growing target species. We also show that priority effects vary with soil conditions, being stronger in clay than sandy soils, and on soils of high nutrient availability. As such, our work emphasises the importance of considering priority effects and local soil conditions in developing management strategies for restoring plant species diversity in grassland.