Species Richness In Plots Research Articles

Biodiversity of macroalgae does not differentially suppress coral performance: The other side of a biodiversity issue.

Hundreds of studies now document positive relationships between biodiversity and critical ecosystem processes, but as ecological communities worldwide shift toward new species configurations, less is known regarding how the biodiversity of undesirable species will shape the functioning of ecosystems or foundation species. We manipulated macroalgal species richness in experimental field plots to test whether and how the identity and diversity of competing macroalgae affected the growth, survival, and microbiome of a common coral in Mo'orea, French Polynesia. Compared to controls without algal competitors, coral growth was significantly suppressed across three macroalgal monocultures, a polyculture of the same three macroalgae, and plots containing inert seaweed mimics; coral mortality was limited and did not differ significantly among treatments. One macroalga suppressed coral growth significantly less than the other two, but none differed from the inert mimic in terms of coral suppression. The composition, dispersion, and diversity of coral microbiomes in treatments with live macroalgae or inert plastic mimics did not differ from controls experiencing no competition. Microbiome composition differed between two macroalgal monocultures and a monoculture versus plastic mimics, but no other microbiome differences were observed among macroalgal or mimic treatments. Together, these findings suggest that algal diversity does not alter harmful impacts of macroalgae on coral performance, which could be accounted for by physical structure alone in these field experiments. While enhancing biodiversity is a recognized strategy for promoting desirable species, it would be worrisome if biodiversity also enhanced the negative impacts of undesirable species. We documented no such effects in this investigation.

Impacts of garlic mustard (Alliaria petiolata, Brassicaceae) invasion on oribatid mites in urban forest soils vary with the size of the invaded patch

Investment in non-native species management should be informed by knowledge of impact, including on native biodiversity and ecosystem function. Oribatid soil mites may be useful to evaluate the impacts of plant invasions since they are bioindicators of disturbance and soil ecosystem health. Still, more research is needed to characterize their responses to plant invasion, especially at the species level. Our objective was to determine the effect of invasion of urban forest understories by an allelopathic weed (garlic mustard, Alliaria petiolata (Brassicaceae)) on belowground oribatid mite species and communities. At two sites in central Alberta (Canada), over two years, we examined adult oribatid (≥ 300 µm) community assemblages, species richness, evenness, diversity, and abundance in plots invaded with garlic mustard and uninvaded plots with native vegetation. Environmental covariates known to be associated with soil invertebrate communities were also evaluated. Results suggest that the spatial extent of the garlic mustard invasion (patch area) mediates its impact on oribatid mite communities. However, there were no community-level impacts when considering invasion as binary (garlic mustard vs. native vegetation). Garlic mustard patch area influenced oribatid community composition and was positively related to species richness and several abundance metrics. The oribatid species we observed benefiting from garlic mustard invasion have been previously associated with disturbed soils. The mechanisms driving these patterns need more research, but we hypothesize they may relate to patch-specific resident times. Site was also a dominant factor influencing oribatid mite communities, and impacts of year, litter depth, and canopy cover were also detected at the species and/or community level. These findings contribute to our understanding of the impact of an invasive weed on bioindicating soil mite communities and species and highlight the importance of considering invasion context, including spatial extent when evaluating the impacts of invasive species on belowground invertebrate communities.

Direct topsoil transfer to already planted reforestation sites increases native plant understory and not ruderals

Forests restored passively or by tree planting can take many decades to be recolonized by native forest understory plant species, if at all. Our study tested (1) the ability of forest topsoil transfer to accelerate the recovery of native forest plant communities in post‐agricultural reforestation sites after tree‐planting and without previous topsoil removal and (2) the effect of adding combinations of woody debris (WD), shrub plantings, and shade shelters (SS) on top of the transferred topsoil. Five 12.5 × 10 m treatment blocks were established in each of three recipient sites, which included two post‐agricultural reforestation sites, and one abandoned gravel pit site. Each treatment blocks received forest topsoil and a combination of additional treatments. Treatment and control plots were sampled for all vascular species in spring and summer. Native forest plant species richness in topsoil recipient plots was similar (p > 0.05) to that of mature donor forest sites, and significantly higher (p < 0.05) than that of passive control plots in the recipient sites. The plant community composition of all topsoil recipient plots had also become more like the donor forests and less like recipient site controls. Only the unplanted gravel pit‐site increased in non‐native ruderal plant species after topsoil transfer. The addition of WD, shrub plantings, or SS had no significant effect after two growing seasons. We recommend that topsoil should when possible be added where trees have already been planted, allowing for shorter time to canopy closure and thereby higher survival of shade‐adapted understory species.

Changes in species diversity along the ephemeral streams in eastern Mediterranean Mountainous Ecosystem, a case study for Ahir Mountain (Kahramanmaraş-Türkiye).

Ephemeral streams are important habitats that support biodiversity, especially in mountainous ecosystems in arid and semi-arid regions, and are among those that will be most affected by global climate change. This study aimed to examine the trends in plant species diversity of ephemeral stream beds and their relationship with environmental variables (aspect, elevation, soil) in the eastern Mediterranean region.For this purpose, 40 sample plots were applied in the valley cross sections of the ephemeral stream beds (valley bottom, side and ridge) on two main slopes (north and south) in 2019. The abundance values of plant species were determined and the number of individuals in each sample plot was counted. In addition, soil samples were taken at a depth of 0-30 cm and analyzed. With the data obtained, the importance value index of all species was calculated, and the diversity and species richness of the sample plots were determined.A total of 130 plant taxa were identified in the study area. The most dominant species were Astragalus kurdicus (IVI value: 25.97), Helichrysum plicatum (21.94), Taeniatherum caput-medusae subsp. crinitum (15.51), Hordeum bulbosum (15.33), Bromus erectus (15.32), and Minuartia juniperina (14.14). Both plant richness and endemism rate showed a significant relationship with increasing elevation. Plant diversity values of south-facing slopes were higher (2.23) than those of north-facing slopes (2.21). In addition, we found that phosphorus is an important factor in the distribution of plant species along the ephemeral stream beds, and as the amount of phosphorus increases, species richness and diversity also increase.

Effect of Long-Term Burning and Mowing Regimes on Ant Communities in a Mesic Grassland

Ecological disturbance is fundamental for grassland management and the maintenance of its biodiversity. Fire and grazing are the primary habitat disturbances influencing the structure and composition of grassland ecosystems, both acting to remove grass biomass. Little is known about the effects of such grass biomass removal on grassland ants, an ecologically dominant faunal group. Our study assesses the response of ant communities to long-term experimental burning and mowing treatments in a South African mesic grassland. The study’s main objectives were (i) to assess the effect of frequency and season of burning and mowing on ant species richness and composition and (ii) to identify indicator species associated with the various grassland management treatments. The experiment included two fully crossed fire treatments: frequency (annual, biennial, and triennial) and season (late winter and after spring rains), along with annual mowing and an undisturbed control. Ants were sampled using pitfall traps in 27 plots, comprising 18 burnt, 6 mown, and 3 controls. The mean species richness in the burnt plots (22.38 ± 3.71) was far higher than in the control (23 ± 2.0) or mown (21.0 ± 2.28) plots. However, the total richness (combining plots) did not vary among treatments. Four of the nine most common species showed a statistically significant response to experimental treatment, but there were no significant treatment effects on overall species composition. Three indicator species (IndVal > 70%) were identified for the control plots, and detector species (IndVal 50–70%) were identified for annual, biennial, and triennial burning treatments. Our findings demonstrate that ant communities in this grassland system are highly resilient to burning and mowing, and that fire promotes diversity at the plot scale. Our identified indicator and detector species can be used as a focus for ongoing monitoring of biodiversity change in our grassland system, including in response to woody expansion.

Tree species richness increases spatial variation but not overall wood decomposition

Empirical evidence for the positive relationship between tree species richness and wood decomposition is weak, despite the greater numbers of decomposers in diverse stands. Tree species identity affects decomposition rates strongly by altering soil communities and micro-environments. It is therefore likely that tree species richness influences spatial variation rather than the mean rate of decomposition. We used a neighbourhood approach to test this hypothesis by quantifying decomposition rates and decomposer activities within deadwood, whilst measuring the surrounding micro-environments.Using the BEF-China experimental platform, we placed three fine branches from seven tree species across richness gradients for one and two years. As expected, plot species richness increased the spatial variation of wood decomposition of three species but decreased the mean rate of wood decomposition of two species. Neighbourhood trees altered wood decomposition in two ways. First, increasing amounts of leaf tannins reduced termite activities and the number of fungal fruitbodies. Second, higher species richness increased tree volumes and thus cooled the understory, which reduced the occurrence and feeding intensity of ectothermic termites. Neighbourhood species richness showed positive effects on decomposer activities (i.e. termite occurrence, fruitbody number and mycelium cover) after two years, probably by weakening resource limitation of deadwood biomass and increasing the stages of decay. Neighbourhood metrics had comparable (after 1 year) and even stronger effects (after 2 years) on decomposer activities than wood traits. Our study reveals that tree species richness promotes spatial variation in wood decomposition rates by enhancing environmental heterogeneity. Our results explain how young regenerating species-rich forests, where termites are the dominant decomposers, can maintain deadwood stocks and decomposer activities over relatively longer time spans.

Diversity stabilizes but does not increase sapling survival in a tree diversity experiment

Tree plantings have the potential to increase species diversity and sequester carbon, yet planting failure and early mortality pose significant barriers to their success. Biodiversity‐ecosystem function theory suggests that diverse tree plantings could improve survival outcomes through either the portfolio or facilitation effect, yet there remain few tests of this hypothesis. Here, we use a large‐scale tree‐diversity experiment (BiodiversiTREE), with monitoring of nearly 8,000 individual trees to test whether (1) tree species diversity increases survival rates, (2) tree diversity stabilizes the risk of planting failure, and/or (3) diversity effects are important relative to other common drivers of seedling mortality (e.g. herbivory and soil moisture). We found that only species identity significantly impacted the likelihood of survival, not plant functional diversity nor plot species richness nor phylogenetic diversity. There were minor effects of elevation and soil moisture on survival, but both explained a very small amount of variation in the data (r2marg ≤ 0.011). Higher tree diversity did, however, strongly reduce variation in survival across plots, with nearly 2‐fold higher coefficients of variation in monocultures (30.4%, 28.4–32.6% 95% bootstrapped confidence interval) compared to 4‐ (16.3%, 13.8–18.7%) and 12‐species plots (12.8%, 10.8–14.7%). Ultimately, our results suggest that employing diverse species can lower the risk of planting failure (i.e. the portfolio effect), but that species selection still plays a large role in early establishment.

Paired plot experiments to assess impact of invasive species on native floral diversity in Pakistan

The threat of invasion is growing globally and endangers biodiversity. Exotic invasive plants are putting a harm to the vegetation of Pakistan’s Pothwar region, which is a biodiversity hotspot. In the current study, the effects of Broussonetia papyrifera, Parthenium hysterophorus, Xanthium strumarium, and Lantana camara on the local flora in the Pothwar area were examined. Two categorical groups (invaded and non-invaded) were used in a dichotomized experimental design to collect data. Using the software PRIMER-7 and IBM SPSS v. 21, different diversity indices including Margalef’s index of species richness, Shannon index of diversity, and Simpson index of dominance were measured and compared between invaded and control plots. In comparison to the experimental plots, the control plots had an average of more individuals and diversity. On a multivariate scale, non-metric multidimensional scaling (nMDS) and analysis of similarity (ANOSIM) revealed higher species richness in control plots. The invasion effect of L. camara was the highest, followed by X. strumarium, P. hysterophorus, and B. papyrifera.

Insect Pest Pheromone Lures May Enhance the Activity of Insectivorous Bats in Mediterranean Vineyards and Apple Orchards

Insectivorous bats may play a significant role in regulating populations of agricultural pests. Currently, few methods are available to enhance the activity of bats in agroecosystems. We asked whether synthetic sex pheromones, used in integrated pest management (IPM) to impede the mating success of major moth pests in vineyards and apple orchards, could also enhance the activity and richness of insectivorous bats, their natural enemies. We hypothesized that applying concentrated sex pheromones of pest moths will alter the movement patterns of male moths, indirectly affecting bat richness and activity. We compared the effect of sex pheromones on bats under two different agricultural management systems: conventional farming and IPM. We used synthetic sex pheromones of Lobesia botrana or Cydia pomonella; both are among the most destructive moth pests in vineyards and apple orchards, respectively. Using passive acoustic monitoring, we compared species richness and bat activity in plots without and with additional pheromones. In both IPM vineyards and IPM apple orchards, total bat activity and species richness significantly increased after applying the pheromone treatment, with a positive correlation between total bat activity and the numbers of moth pests in the vineyards. In conventional vineyards, bat species richness increased significantly, but not total bat activity. IPM vineyards had significantly higher species richness than conventional vineyards, both before and after the pheromone treatment. Our study shows that moth pheromone lures, commonly used as a pest control method, may also attract insectivorous bats, which in turn may further suppress the pests. These findings highlight the potential of insectivorous bats as pest control agents and call for further research directed at integrating them in IPM practices.

Comparative diversity of vascular plants in black alder floodplain and swamp forests of Central European biogeographical regions.

Plant species diversity of black alder-dominated forests was studied in three biogeographical regions (Alpine, Continental and Pannonian) of Central Europe. They were represented by regions of the Polish Plain (Continental), the High Western Carpathians and Matricum of the Western Carpathians (Alpine) and the Pannonian lowland (Pannonian). We analysed 35 plots per region in order to identify: i) local alpha (α) diversity defined as the counted number of plant taxa occurring in a single sampling plot, ii) amongst-site beta (β) diversity, iii) regional (γ) diversity defined as the total species richness of all sampling plots and iv) zeta diversity (ζ) as a generalisation of beta diversity. We recorded a total of 432 vascular plant taxa in all bioregions; more than 13% were alien plants. Statistically significant differences in species richness (α) of both native and alien plants were found between assemblages of the regions. The High Western Carpathians showed the highest native and the lowest alien plant species richness. Total β-diversity was high in all regions, but significantly differed amongst regions only for alien plant species. Cumulative native and alien species richness (γ) was the highest and lowest in the High Western Carpathians and Matricum of Western Carpathians, respectively. Our results identified the High Western Carpathians as a hotspot for diversity of native plants in Central European black alder-dominated forests.

How do patch burnings affect ant communities and seed removal in a subtropical grassland?

Disturbances modify local abiotic properties, habitat structure and resource availability, shaping community assembly and ecological interactions. Open ecosystems have an evolutionary relationship with fire. We evaluated the effects of patch burnings on grassland ant communities and patterns of seed removal. We established 14 plots of 10 m2 in pairs in a disturbance-suppressed grassland in South Brazil. A random plot of each pair was burned, and another plot was the control. We accessed ant communities with pitfall-traps and sweeping net, and seed removal with seed traps in all plots prior the experimental fires, and then on three occasions following fires. We recorded 57 ant species belonging to 29 genera. Ant species composition did not significantly vary between treatments neither did ant body size. We detected significantly positive fire effects on ant richness after 1 month and 12 months, mediated by the increase in plant species richness in burned plots. Mean seed removal rates were increased in burned plots after 1 month. We showed that prescribed patch burnings in fire-prone grasslands promoted ant richness, and their foraging activity. Our study may serve as a basis for conservation decisions, showing the importance of maintenance of disturbances in grasslands.

Community structure of ants (Hymenoptera: Formicidae) in an open habitat: the importance of environmental heterogeneity and interspecific interactions

Ant species are highly sensitive to environmental changes, and ant community structure can be shaped by environmental heterogeneity and interspecific interactions. We tested 2 hypotheses: (1) vegetation structure negatively affecting ant diversity in simplified habitats and (2) interspecific interactions shaping ant communities. We collected ants on shrubs distributed in 16 sampling units of 100 m2 using the entomological umbrella and beating technique in a regenerating Cerrado area of Brazil. The richness, abundance and average height of the plants were used as a measure of environmental heterogeneity. A total of 457 ants belonging to 17 species were sampled. We observed higher ant species richness in plots with greater plant abundance and lower plant height. We observed a negative relationship between ant abundance and plant height per plot. These results corroborate that vegetation structure negatively affects ant diversity in simplified habitats. The observed values of co-occurrence index differed from the expected values of simulated matrices, suggesting that competition shaping ant community in simplified habitats. We highlight the importance of conserving small trees, especially in structurally less complex habitats, because they represent key elements that harbor high ant species diversity.

Response of riparian vegetation to short- and long-term hydrologic variation.

Increasing demand for river water now conflicts with an increasing desire to maintain riparian ecosystems. Efficiently managing river flows for riparian vegetation requires an understanding of the time scale of flow effects, but this information is limited by the absence of long-term studies of vegetation change in response to flow variation. To investigate the influence of short- and long-term flow variability and dam operation on riparian vegetation, we determined the occurrence of 107 plant species in 133 permanent plots of known inundating discharge along the Gunnison River in Colorado on five different occasions between 1990 and 2013. Individual species moved up and down the gradient of inundating discharge coincident with increases and decreases in mean annual flow, and the correlations between flow and species occurrence were strongest when flows were weighted by time before vegetation sampling with a median half-life of 1.5 years. Some tall, rhizomatous, perennial species, however, responded to flows on a longer time scale. Logistic regression of species occurrence showed a significant relation with inundation duration for 70 out of 107 species. Plot species richness and total vegetative cover decreased in association with desiccation at low inundation durations and with fluvial disturbance at high inundation durations. Within-plot similarity in species occurrence between years decreased strongly with increasing inundation duration. Moderate inundation durations were dominated by tall, rhizomatous, perennial herbs, including invasive Phalaris arundinacea (reed canary grass). Over the 23-year study period, species richness declined, and the proportion of rhizomatous perennials increased, consistent with the hypothesis that decreases in flow peaks and increases in low flows caused by flow regulation have decreased establishment opportunities for disturbance-dependent species. In summary, annual-scale changes in vegetation were strongly influenced by flow variation, and decadal-scale changes were influenced by decreases in fluvial disturbance from upstream flow regulation beginning decades prior to the onset of this study.

Long-term effects of sheep-grazing and its removal on vegetation dynamics of British upland grasslands and moorlands; local management cannot overcome large-scale trends

The upland and mountainous regions of northern Europe provide a wide variety of ecosystem services. However, these ecosystem services are highly vulnerable to environmental and land-use change. To ensure their future conservation, it is therefore, essential to understand whether upland plant communities will respond positively or negatively to a range of environmental factors such as grazing pressure and landscape-scale factors such as changes in atmospheric SO2 and NOx deposition. To understand this, here, we describe the long-term trends in four UK upland communities (high-level grassland, intermediate grassland, blanket bog, high-level bog) using four replicated long-term experiments examining the effects of sheep grazing compared to no-sheep grazing in Moor House (from 1954 to 2016). Our results showed that species richness and abundance recovered in grazed plots after 2000, with improvements in species richness and abundance of vascular plants, mosses, and liverworts. Unfortunately, no improvement was found for lichens. Species richness, vascular plants, and mosses recovered the fastest, and much faster than liverworts. There was no evidence of slower recovery of species richness and abundance in plots where sheep grazing was removed. These results are consistent with longitudinal studies suggesting recovery after 2000 as a result of reduced atmospheric deposition. Although trends in diversity and abundance in the grazed and ungrazed plots were not identical, they were not markedly different either. The similar richness and abundance trends in the grazed and ungrazed plots found in each plant community suggest that within-community dynamics may overcome initial differences between the grazing treatments over time. In contrast, differences in richness and abundance among plant communities over time suggest that some landscape-scale trends, such as those caused by a reduction in nutrient inputs, initiate community-dependent recovery.

Land-use intensity and landscape structure drive the acoustic composition of grasslands

Understanding drivers and monitoring changes of biodiversity forms the basis for evidence-based management and policy recommendations that aim to reduce biodiversity loss and to ensure the delivery of ecosystem services on which we rely. Ecoacoustic monitoring can be applied across large spatial and temporal scales, offering the potential for less resource-intensive ecosystem monitoring. Indices of acoustic diversity have been shown to correlate with species richness of various taxa, as well as vegetation and landscape structure. In order to apply ecoacoustic monitoring at large scales we need to improve our understanding of the effects of local and regional land-use on acoustic patterns, and assess how temporal aspects of acoustic patterns can be integrated in these analyses. We hypothesized that land-use intensity and landscape structure affect species richness and composition of birds and orthopteran, and therefore indirectly affect acoustic diversity and composition. To test this, we set up autonomous recording systems in grassland plots along land-use intensity gradients in three regions in Germany. We applied structural equation modelling to analyze the direct and indirect drivers of acoustic diversity and composition, including mowing and grazing intensities, landscape diversity, distance to the nearest road, vascular plant species richness as well as bird and orthopteran species richness and composition. Single indices of acoustic diversity did not reflect changes in bird or orthopteran species richness, making them poor predictors for local land-use related changes in species richness in grassland plots. Acoustic composition (non-metric multidimensional scaling combination of mean monthly acoustic indices at different day phases), however, did relate to differences in landscape structure, land-use intensity, vocalizing species composition and orthopteran species richness. We propose the developed acoustic composition metric as suitable proxy to detect ecosystem changes in grasslands.

Allelopathic potential of Ficus retusa L. leaf litter on understory vegetation in urban gardens

Pruning Ficus trees in urban green spaces may lead to the accumulation and spread of their leaf litter on the understory vegetation. This study was conducted to evaluate the allelopathic effect of Ficus retusa L. leaf litter on the understory species in urban gardens. A field study showed that the plant cover and species richness of litter-affected plots were lower than those of litter-free areas. The litter-affected soils had substantially lower pH and higher electrical conductivity. In a greenhouse experiment, litter-affected soil significantly inhibited the emergence and growth of understory species selected for the purpose of this study: Melilotus indicus (L.) All., Trifolium resupinatum L. and Amaranthus viridis L. Osmotic potentials equivalent to those of the litter-affected soils did not affect emergence or growth of these species. A spectrophotometric analysis indicated that the litter-affected soils contained larger amounts of phenolics and flavonoids. An HPLC analysis revealed that the litter-affected soils contained higher concentrations of free phenolic and flavonoid allelochemicals. These results demonstrate that F. retusa leaf litter may reduce plant cover and species richness. The significant inhibition in both field and greenhouse experiments could be attributed to phenolic and flavonoid allelochemicals released from the tree litter, as the osmotic potential of the litter had no effect on the understory species. The allelopathic potential of F. retusa leaf litter plays at least a partial role in reducing urban vegetation.

Recovery of woody but not herbaceous native flora 10 years post old‐field restoration

Abstract Vegetation recovery in old fields towards mature reference states is often limited by abiotic and biotic thresholds resulting from agricultural land use legacies, as commonly highlighted using state and transition models. Old‐field restoration may include interventions (e.g. planting of vegetation) to overcome these thresholds and assist transition between states. However, our understanding of the effectiveness of these interventions is limited. Using a point‐intercept transect method, we surveyed nine sites, each comprising a triplet of fallow cropland, planted old field and woodland reference plots to reflect states of old‐field restoration, from the degraded state to the reference state. We compared ground cover attributes, and richness and cover of woody and herbaceous flora species, using ANOVA and multivariate analyses. We found that a decade after planting, cover of leaf litter and woody debris in planted old fields were significantly higher than in the fallow croplands; however, woodland reference conditions were not achieved. Cover of logs was similar to the fallow cropland. Woody species cover and richness were similar in planted old fields and woodland reference plots, with planted old fields having more than 60% of the shrub species richness and cover, and similar tree species richness, to the woodland reference plot. In contrast, whilst herbaceous species contributed more than half the plant species richness in reference woodland plots, there were significantly fewer herbaceous species in the planted old fields, which were more similar to the fallow croplands. Cover of exotic annual forbs in planted old fields was about half that of fallow cropland, and exotic annual grass cover was similar to the reference woodland. Our results show that active restoration of old fields increased leaf litter, woody debris and cover and richness of trees and perennial shrubs. However, native herbaceous species richness, and to some extent cover, remained similar to the fallow cropland. To effect transitioning of the herbaceous layer to the woodland reference state, further intervention such as removal of exotics, followed by sowing or planting native herbaceous species, may be necessary.

Vascular plant species diversity in Southeast Asian rice ecosystems is determined by climate and soil conditions as well as the proximity of non-paddy habitats

Rice ecosystems vary greatly in climate, edaphic conditions, landscape heterogeneity, agricultural management and biodiversity. However, ongoing land use intensification and conversion to large-scale monoculture are threatening this diversity. We analyzed how rice-growing regions in Southeast Asia differ in diversity and composition of vascular plants in paddy rice ecosystems, and how the local and regional biodiversity of these plants is determined by variations in abiotic conditions, habitat type (paddy vs. bunds) and the proximity of non-paddy habitats. The vegetation of paddies and their bunds was surveyed in seven important rice production regions located in highlands and lowlands of Vietnam and the Philippines. Within the regions we sampled 67 pairs of study sites comprising a total of 122 paddies and 134 bunds. We identified major drivers of field-level weed diversity (alpha diversity) separately for bunds and paddies. Species turnovers (beta diversity) across sampling sites, between paddies and their bunds, and between regions were visualized using the Bray-Curtis coefficient of dissimilarity and DCA ordinations. Species richness on bunds was mainly influenced by the proximity of non-paddy habitats, mean annual temperature and soil acidity. Soil moisture was the decisive factor for the variation in paddy weed richness. In both habitat types, Shannon diversity and the number of insect-pollinated plants showed patterns similar to species richness. Regional differences in plot species richness were stronger on bunds than in paddies. Species turnover was high among habitat types and between upland and lowland regions. Future ecological engineering approaches can build on our findings to promote pollination services more efficiently in Southeast Asian rice landscapes.

The role of plants and soil properties in the enzyme activities of substrates on hard coal mine spoil heaps

Knowledge about biotic (plant species diversity, biomass) and/or abiotic (physicochemical substrate parameters) factors that determine enzyme activity and functional diversity of the substrate on hard coal spoil heaps is limited. Spontaneously developed vegetation patches dominated by herbaceous species commonly occurring on these spoil heaps: grasses (Poa compressa, Calamagrostis epigejos) and forbs (Daucus carota, Tussilago farfara), were examined. The activity of dehydrogenase and alkaline phosphatase was twice as high in plots dominated by grass species compared with those dominated by forbs. Significant positive correlations were found between the activity of dehydrogenase and alkaline phosphatase with pH, available P, soil moisture, and water holding capacity and negative correlations between the activity of urease and soil organic carbon. Strong positive correlations were found between values for Shannon–Wiener diversity index, evenness, species richness and soil functional diversity in plots dominated by grasses. We found that the soil physicochemical parameters had a greater impact on enzyme activity of the substrate than plant biomass and species diversity. However, grasses, through their extensive root system, more effectively increased enzyme activity and health of the substrate than other herbaceous species, and as they stabilize the substrate and form dense plant cover, they can be recommended for reclamation purposes.

Multiple comparisons of diversity indices invaded by Lantana camara.

Current study assessed the impact of Lantana camara invasion on native plant diversity in Pothohar region of Pakistan. The approach used for study was random samplings and comparisons of diversity indices [number of species (S), abundance (N), species richness (R), evenness (Jꞌ), Shannon diversity index (Hꞌ) and Simpson index of dominance (λ)] with two categorical factors i.e., invaded and non-invaded (control). Control plots harboured by an average of 1.74 more species/10m2. The control category was diverse (Hꞌ=2.56) than invaded category (Hꞌ=1.56). The higher value of species richness in control plots shows heterogeneous nature of communities and vice versa in invaded plots. At multivariate scale, ordination (nMDS) and ANOSIM showed significant magnitude of differences between invaded and control plots at all sites. The decrease in studied diversity indices in invaded over control sites indicated that plant communities become less productive due to Lantana invasion.