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opencc-zeroJan 2022View details →

Data from: Turnover and nestedness drive plant diversity benefits of organic farming from local to landscape scales

Biodiversity-benefits of organic farming have mostly been documented at the field scale. However, these benefits from organic farming to species diversity may not propagate to larger scales, because variation in the management of different crop types and semi-natural habitats in conventional farms might allow species to cope with intensive crop management. We studied flowering plant communities using a spatially replicated design in different habitats (cereal, ley and semi-natural grasslands) in organic and conventional farms, distributed along a gradient in proportion of semi-natural grasslands. We developed a novel method to compare the rates of species turnover within and between habitats, and between the total species pools in the two farming systems. We found that the intra-habitat species turnover did not differ between organic and conventional farms, but that organic farms had a significantly higher inter-habitat turnover of flowering plant species compared to conventional ones. This was mainly driven by herbicide-sensitive species in cereal fields in organic farms, as these contained 2.5 times more species exclusive to cereal fields compared to conventional farms. The farm-scale species richness of flowering plants was higher in organic than conventional farms, but only in simple landscapes. At the inter-farm level, we found that 36% of species were shared between the two farming systems, 37% were specific to organic farms while 27% were specific to conventional ones. Thus, our results suggest that that both community nestedness and species turnover drive changes in species composition between the two farming systems. These large-scale shifts in species composition were driven by both species-specific herbicide and nitrogen sensitivity of plants. Our study demonstrates that organic farming should foster a diversity of flowering plant species from local to landscape scales, by promoting unique sets of arable-adapted species that are scarce in conventional systems. In terms of biodiversity conservation, our results call for promoting organic farming over large spatial extents, especially in simple landscapes, where such transitions would benefit plant diversity most.

Linking genetic diversity and species diversity through plant-soil feedback

Genetic diversity and species diversity are typically studied in isolation despite theory showing they likely influence one another. Here, we used simplified communities of one or two populations of one or two species to test whether linkages between genetic and species diversity can be mediated by interactions between plants and their soil microbiota, or microbe-mediated plant-soil feedback (PSF). Interspecific PSF promotes the maintenance of species diversity when plants grow better with heterospecific soil microbes than with conspecific microbes. Similarly, intraspecific PSF promotes the maintenance of genetic diversity when plants grow better with heterogenotypic than with congenotypic microbes. In a two-generation greenhouse experiment, we conditioned the soil microbial community with pairs of plants that were either two individuals of the same species (lower species diversity) or one individual of each of two species (higher species diversity), and with pairs of plants that were either two individuals from the same population (lower genetic diversity) or one individual from each of two populations (higher genetic diversity). We then tested the effects of these microbial communities on plant growth in a second generation. We found that higher genetic diversity reduced the ability of interspecific PSF to promote plant species diversity, and for one of our two study species, higher species diversity reduced the ability of intraspecific PSF to promote plant genetic diversity. If these patterns occur in more diverse communities, then our results suggest that PSF may dampen the negative effects of diversity loss by promoting diversity at other levels of biological organization.

PRMI: A dataset of minirhizotron images for diverse plant root study

Understanding a plant's root system architecture (RSA) is crucial for a variety of plant science problem domains including sustainability and climate adaptation. Minirhizotron (MR) technology is a widely-used approach for phenotyping RSA non-destructively by capturing root imagery over time. Precisely segmenting roots from the soil in MR imagery is a critical step in studying RSA features. In this paper, we introduce a large-scale dataset of plant root images captured by MR technology. In total, there are over 72K RGB root images across six different species including cotton, papaya, peanut, sesame, sunflower, and switchgrass in the dataset. The images span a variety of conditions including varied root age, root structures, soil types, and depths under the soil surface. All of the images have been annotated with weak image-level labels indicating whether each image contains roots or not. The image-level labels can be used to support weakly supervised learning in plant root segmentation tasks. In addition, 63K images have been manually annotated to generate pixel-level binary masks indicating whether each pixel corresponds to root or not. These pixel-level binary masks can be used as ground truth for supervised learning in semantic segmentation tasks. By introducing this dataset, we aim to facilitate the automatic segmentation of roots and the research of RSA with deep learning and other image analysis algorithms.

Changes in the direction of the diversity-productivity relationship over fifteen years of stand development in a planted temperate forest

Experiments manipulating diversity in both forests and grasslands have often observed a positive diversity-productivity relationship (DPR) which tends to strengthen during plant community development. This pattern is generally attributed to an increase in niche complementarity or facilitation. Most analyses do not examine species dominance and density, which also change over time. Moreover, how neighbourhood scale interactions among tree species affect the DPR is not well understood. We analysed growth and mortality data from the Simplex experiment, a part of the BIOTREE tree diversity experiment. Simplex consists of 36 plots each planted with four common and commercially important tree species to create a gradient of tree species evenness at two tree densities (6667 and 3556 trees ha-1). We test whether: i) the effect of evenness on total aboveground biomass productivity increase with stand development (year), ii) the effect of evenness on productivity is stronger in dense plots; iii) intra-specific competition from neighbours negatively affect the growth of dominant species more strongly compared to co-dominant species, and whether this negative effect is stronger in denser plots. The direction of DPR was initially negative because the fast-growing long-lived pioneer Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) dominated. However, with time, shade tolerant Norway spruce (Picea abies (L.) Karst.) and European beech (Fagus sylvatica L.) increased in abundance (by biomass), and the relationship between evenness and biomass increment changed from negative to positive in high-density plots. Neighbourhood analyses revealed that for Douglas fir and Norway spruce, conspecifics reduced individual growth rates across density levels and years. Synthesis: We observed a shift in the diversity-productivity relationship over 15 years in our experiment. Over time, increasing intraspecific competition limited the increment of the abundant Douglas fir in uneven plots, and a persistent increase in the abundance (by biomass) of shade tolerant Norway spruce and European beech in even plots led to a higher community biomass increment, which led to a positive DPR. Emergence of a positive DPR in temperate forest plantations requires significant time and is importantly promoted by diversity at the neighbourhood scale (intimate mixtures) as well as higher density planting.

Data from: Partitioning the effects of plant diversity on ecosystem functions at different trophic levels

Biodiversity effects on ecosystem functioning can be partitioned into complementarity effects, driven by many species, and selection effects, driven by few. Selection effects occur through interspecific abundance shifts (dominance) and intraspecific shifts in functioning. Complementarity and selection effects are often calculated for biomass, but very rarely for secondary productivity, i.e. energy transfer to higher trophic levels. We calculated diversity effects for three functions: aboveground biomass, insect herbivory and pathogen infection, the latter two as proxies for energy transfer to higher trophic levels, in a grassland experiment (PaNDiv) manipulating species richness, functional composition, nitrogen enrichment and fungicide treatment. Complementarity effects were on average positive and selection effects negative for biomass production and pathogen infection and multiple species contributed to diversity effects in mixtures. Diversity effects were on average less pronounced for herbivory. Diversity effects for the three functions were not correlated, because different species drove the different diversity effects. Benefits (and costs) from growing in diverse communities, be it reduced herbivore or pathogen damage or increased productivity either due to abundance increases or increased productivity per area were distributed across different plant species, leading to highly variable contributions of single species to diversity effects on different functions. These results show that different underlying ecological mechanisms can result in similar overall diversity effects across functions.

Historical biogeography and character-mapping of Hiptage (Malpighiaceae) corroborate Indochina's rainforests as one of the main sources of plant diversity in Southeastern Asia

In Malpighiaceae, Hiptage represents one of the seven past dispersal events from the Neotropics to the Paleotropical region, being by far the most widely diversified and distributed genus of Paleotropical Malpighiaceae. In this study, we tested the monophyly of the current infrageneric classification of Hiptage with a dated and calibrated molecular phylogeny. We also reconstructed ancestral areas to elucidate which route led to the colonization of Southeast Asia by the most recent common ancestor (MRCA) of this genus (Mainland or Indian routes). The pre-existing infrageneric classification of Hiptage was recovered as non-monophyletic due to being solely based on homoplasic morphological characters, such as the presence and number of sepal nectar glands. Regarding its biogeography, the MRCA of Hiptage arose in the rainforests of southeast Asia ca. 24.0 Mya and greatly diversified in this region. Few lineages have dispersed eastward to the pacific islands or westwards to India. Based on our results, we hypothesize that the MRCA of Hiptage did not take the Indian route to reach Southeastern Asia. Instead, it reached this region by past mainland forest connections between North America-Europe (Boreotropical hypothesis) and southeast Asia. Nonetheless, distribution ranges for the species of Hiptage must be carefully revised, and the five species of Hiptage endemic to India must also be sampled so we can properly test which route led the MRCA of Hiptage to reach Southeast Asia in the early Miocene.

opencc-by-4.0Mar 2022View details →

Mind the Gap: Reach and Mechanical Diversity of Searcher Shoots in Climbing Plants

This dataframe corresponds to the article Hattermann et al. "Mind the Gap: Reach and Mechanical Diversity of Searcher Shoots in Climbing Plants" <table> <tbody> <tr> <td>Variable Abbreviation</td> <td>Description of the variable</td> <td>Type of variable</td> <td>Units</td> </tr> <tr> <td>ID</td> <td>Sample identification label at the shoot level</td> <td>Nominal variable</td> <td> </td> </tr> <tr> <td>Taxa</td> <td>Species name</td> <td>Nominal variable</td> <td> </td> </tr> <tr> <td>family</td> <td>Family name</td> <td>Nominal variable</td> <td> </td> </tr> <tr> <td>ds</td> <td>Biomes where shoots have been sampled - "temperate" corresponds to Montpellier, south of France and tropical corresponds to Sinnamary, French Guiana </td> <td>Nominal variable</td> <td> </td> </tr> <tr> <td>Leaf_expanded</td> <td>Indicates whether a shoot has been considered with at least one expanded leaf (1) or with no leaves (0)</td> <td>Discrete variable</td> <td> </td> </tr> <tr> <td>Group</td> <td>Functional group based on the climbing habit at the species level</td> <td>Nominal variable</td> <td> </td> </tr> <tr> <td>reach</td> <td>Distance in a straight line from the base to the apex of the searcher shoot (here called the “reach”)</td> <td>Continuous variable</td> <td>cm</td> </tr> <tr> <td>length</td> <td>Length of the searcher shoot</td> <td>Continuous variable</td> <td>cm</td> </tr> <tr> <td>A1_diam_basal</td> <td>Basal diameter of the searcher shoot (measured at the base of the searcher shoot)</td> <td>Continuous variable</td> <td>mm</td> </tr> <tr> <td>N_leaves</td> <td>Number of leaves</td> <td>Discrete variable</td> <td> </td> </tr> <tr> <td>seco_mom_I</td> <td>Second moment of area (I) of the measured basal segment (in 4-point bending) of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>young_mod_E</td> <td>Structural Young's modulus (E) of the measured basal segment (in 4-point bending) of the searcher shoot from I and EI</td> <td>Continuous variable</td> <td>MN.m-2</td> </tr> <tr> <td>flex_rig_EI</td> <td>Flexural bending rigidity (EI) of the measured basal segment (in 4-point bending) of the searcher shoot</td> <td>Continuous variable</td> <td>N.mm^2</td> </tr> <tr> <td>total_freshmass</td> <td>Freshmass of the searcher shoot (including stems, laminas and petioles)</td> <td>Continuous variable</td> <td>g</td> </tr> <tr> <td>lam_freshmass</td> <td>Lamina freshmass borne by the searcher shoot</td> <td>Continuous variable</td> <td>g</td> </tr> <tr> <td>total_drymass</td> <td>Total drymass of the searcher shoot (including stems, laminas and petioles)</td> <td>Continuous variable</td> <td>g</td> </tr> <tr> <td>lam_drymass</td> <td>Lamina drymass borne by the searcher shoot</td> <td>Continuous variable</td> <td>g</td> </tr> <tr> <td>lam_area</td> <td>Lamina fresh area of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Pith</td> <td>Medullary parenchyma cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Pith_fibers</td> <td>Medullary fibre cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Xylem</td> <td>Xylem vessel and fibres cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Xylem_ray</td> <td>Xylem parenchymatous ray cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Phloem</td> <td>Phloem cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Cortex</td> <td>Cortical parenchyma cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Sclereids</td> <td>Cortical sclereids cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Cort_fibers</td> <td>Cortical fibre cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Collenchyma</td> <td>Collenchyma cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>A_Periderm</td> <td>Periderm cross-sectional area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^2</td> </tr> <tr> <td>I_Pith</td> <td>Medullary parenchyma second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Pith_fibers</td> <td>Medullary fibre second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Xylem</td> <td>Xylem vessel and fibres second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Xylem_ray</td> <td>Xylem parenchymatous ray second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Phloem</td> <td>Phloem second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Cortex</td> <td>Cortical parenchyma second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Cort_fibers</td> <td>Cortical sclereid second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Sclerites</td> <td>Cortical fibre second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Collenchyma</td> <td>Collenchyma second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> <tr> <td>I_Periderm</td> <td>Periderm second moment of area at the base of the searcher shoot</td> <td>Continuous variable</td> <td>mm^4</td> </tr> </tbody> </table>

opencc-zeroMar 2022View details →

Environment driven changes in diversity of riparian plant communities along a mountain river

The study of changes in species richness and composition along rivers has focused on large spatial scales. It has been ignored that in different sections of the river (high mountain area, middle zone and river mouth) the specific environmental conditions can generate different longitudinal patterns of the species richness and composition. In this study we determine if species richness and composition of the riparian plant communities change along a mountain river and if these changes are related with environmental variables. We expect an increase in species richness and turnover along the river, that the upstream communities would be a subset of the downstream communities and that such would be related to edaphic and hydrologic conditions. To test this, we sampled three strata of the riparian vegetation (upper: individuals with <1 cm of ND, middle: individuals with >1 cm of ND, low: individuals with >1 m tall) in a set 15 sites that we place along a mountain river. Additionally, we recorded topographic, hydrological, morphological, and soil variables. We performed correlation analyzes to determine if changes in species richness and turnover were related to increased distance to the origin of the river. Also, we obtained the nestedness and evaluated the importance of environmental variables with GLM, LASSO regression and CCA. With the increase in distance the species richness decreases in the upper stratum, but not in the middle and the low stratum (although the highest values were observed near the origin of the river), the turnover increase in all strata and the upstream communities were not a subset of the downstream communities. The changes in species richness and composition were related to topographic (altitude), hydrological (flow) and edaphic (conductivity and pH) variables. Our results indicate that at small spatial scales the patterns of richness and composition differ from what has been found at larger spatial scales and that these patterns are associated with environmental changes in the strong altitude gradients of mountain rivers.

opencc-zeroApr 2022View details →

Data from: Plant diversity improves resistance of plant biomass and soil microbial communities to drought

1. Biodiversity is known to affect ecosystem resistance and have implications for the maintenance of ecosystem functions and services under climate change. Compared to numbers of studies focusing on aboveground vegetation, the response of belowground communities to abiotic stresses along plant diversity gradients is often ignored and is considered an important knowledge gap in ecosystem ecology. Here we conducted an integrative research to evaluate the resistance of plant biomass, and soil microbial communities and associated functional profiles to drought under varying plant diversity. 2. We carried out a three-year manipulation experiment by factorially controlling plant diversity gradient (1, 2, 4, and 8 species richness) and soil moisture treatment (drought and non-drought), and investigated the responses of plant biomass, soil bacterial and fungal diversity and community composition, soil glomalin, and five key soil enzymes. 3. We found that plant diversity significantly improved the resistance of soil fungal communities and microbial functional profiles characterized by soil glomalin and five key enzymes, which was partly driven by the availability and accessibility of soil resources (e.g., soil moisture and organic matter) mediated by plant diversity. Further, our results indicated that the enhanced resistance of fungal communities was consistent with ecological insurance theory that diverse fungal communities at high plant diversity had a higher probability of containing taxa that adapt to drought. 4. Synthesis. Our study provides novel empirical insights into the mechanism underlying the regulatory effect of plant diversity on resistance of aboveground vegetation and belowground biota to drought, with implications for understanding ecosystem response to climate change and improving biodiversity conservation practices.

opencc-by-4.0May 2022View details →

Aphid conservation biological control in arable crops via flower strips: the predominant role of plant resources over diversity effects

Dataset and R code

opencc-zeroJun 2022View details →

Diversity-conditioned soil strengthens plant diversity-productivity relationship

How biodiversity affects terrestrial productivity is important to the maintenance of ecosystem services under global change. Although the crucial role of plant-soil feedbacks (PSF) in determining diversity-productivity relationship has been increasingly recognized in recent years, its legacy effects on subsequent diversity-productivity relationship are still unclear. We conducted a classic PSF experiment to assess how plant diversity-conditioned soils influenced subsequent plant diversity-productivity relationships, where three plant diversity levels (1, 4, and 8 species) were planted in soils conditioned at three diversity levels (conditioned by 1, 4, and 8 species for 3 years). In addition, to test the role of soil microbial diversity in mediating the effects of soil conditioning diversity, the three plant diversity levels were planted with low, moderate, and high soil biodiversity created by a soil inoculum dilution. The results showed that plant productivities were promoted by mixed-conditioned soils (4 and 8 species) compared to mono-conditioned soils (1 species). Productivity was positively related to planted diversity in mixed-conditioned soils, while showing no relation to planted diversity in mono-conditioned soils. Productivity was promoted by soil biodiversity when 4 and 8 species were mixed planted, while it did not change when 1 species was planted. Synthesis and applications. Our results highlight that PSF is crucial to strengthening the positive effects of biodiversity on productivity, implying that diversifying cropping systems should be encouraged in agroecosystem management to benefit from positive PSF effects. The importance of soil legacy for optimizing plant productivity is particularly important for conditioning soils with an intermediate number of plant species.

opencc-zeroJul 2022View details →

Effects of spatial distance and woody plant cover on beta diversity point to dispersal limitation as a driver of community assembly during post-fire succession in a Mediterranean shrubland

Beta diversity, and its components of turnover and nestedness, reflect the processes governing community assembly, such as dispersal limitation or biotic interactions, but it is unclear how they operate at the local scale and how their role changes along post-fire succession. Here, we analyzed the patterns of beta diversity and its components in a herbaceous plant community after fire, and in relation to dispersal ability, in Central Spain. We calculated multiple site beta diversity (βSOR) and its components of turnover (βSIM) and nestedness (βSNE) of all herbaceous plants, or grouped by dispersal syndrome (autochory, anemochory, zoochory), during the first three years after wildfire. We evaluated the relationship between pairwise beta diversity (βsor), and its components (βsim, βsne), and spatial distance or differences in woody plant cover, a proxy of biotic interactions. We found high multiple-site beta diversity dominated by the turnover component. Community dissimilarity increased with spatial distance, driven mostly by the turnover component. Species with less dispersal ability (i. e. autochory) showed a stronger spatial pattern of dissimilarity. Biotic interactions with woody plants contributed less to community dissimilarity, which tended to occur through the nestedness component. These results suggest that dispersal limitation prevails over biotic interactions with woody plants as a driver of local community assembly, even for species with high dispersal ability. These results contribute to our understanding of post-fire community assembly and vegetation dynamics.

opencc-zeroDec 2021View details →

A dataset for pollinator diversity and their interactions with plants in the Pacific NorthWest

Pollinator populations have declined substantially in recent years. The resulting loss in pollination services has both ecological and economic consequences including reductions in plant diversity and crop production and lower food security. Datasets that identify pollinators and their plant hosts are of utmost importance in order to understand the main causes of pollinator declines. Here we present a dataset, which contains 67,954 individual pollinator records. The data has been collected across the Pacific Northwest, primarily focused in British Columbia (Canada), with 182 individual sites over 11 years, between 2005 and 2017. This dataset comprises multiple studies that aimed to collect information on pollinator abundance, diversity and their interactions with plants. Overall, the dataset includes 937 morphospecies (of which 482 were identified to species) of pollinators across 105 families, including data for bees, wasps, butterflies, moths and flies. We also present information on the interactions of these species, with 473 species of plants. This data set is released for non-commercial use only. Credits should be given to this paper (i.e., proper citation).

Data from: Effects of climate and topography on the diversity anomaly of plants disjunctly distributed in eastern Asia and eastern North America

Aim: Differences in physiography have been proposed to explain the diversity anomaly for vascular plants between environmentally similar regions of eastern Asia (EAS) and eastern North America (ENA). Here, we use plant species within disjunct genera to examine whether differences in topography contribute to the diversity anomaly and whether the richness–environment relationships differ between regions. Disjuncts are used to ensure that the diversity anomaly relates to post-disjunction evolution and diversification rather than regional differences in clade ages or immigration. Location: EAS and ENA. Time period: Current. Major taxa studied: Plant taxa disjunctly distributed in EAS and ENA. Method: We compiled county-level plant distribution data, and calculated species richness and variables of topography and climate within unit grid cells. We compared estimated coefficients of region effects among models, where richness was fitted with or without topography and climate. Topography and climate were also used to separately model within-region spatial diversity patterns using spatial simultaneous autoregressive error models. Results: The coefficients of region effects varied from -0.776 for the model only including region to -0.309 when topography was controlled for, but remained significant. Climate dominated the spatial diversity patterns in ENA. In contrast, the influence of climate (14.2%) on species richness was weaker than that of topography (18.3%) in warm EAS. Relations to elevation and temperature varied between regions, shifting between positive and negative relationships in several cases. Main conclusion: Our results demonstrate that variability in local topography contributes to the strong regional anomaly in plant species richness between EAS and ENA. Nevertheless, the diversity anomaly persists after controlling for local topography and climate. EAS and ENA also exhibit contrasting richness–environment relationships, providing another divergent aspect between the EAS-ENA disjunct floras. Our findings highlight that regional differences in topography or other environmental factors may underlie the diversity anomaly.

Tree mixtures increase bird taxonomic and functional diversity over pure stands of tree species planted outside their natural range—but not over pure native stands

Recent biodiversity loss has emphasized the necessity to critically evaluate the consequences of human alterations of forest ecosystems. Stand diversification via tree species mixtures and the use of non-native tree species are two such alterations currently gaining importance as climate change adaptations. However, the effects of local versus regional tree mixing on associated biodiversity and notably the modifying role of tree species growing outside their natural range remain poorly understood. We assessed how monocultures and mixtures of native and introduced tree species influence the taxonomic and functional diversity of northwest German bird communities at stand and landscape scales. We focused on the dominant natural tree species (Fagus sylvatica) and economically important conifer species planted outside their natural range (the native Picea abies and non-native Pseudotsuga menziesii). We found that bird species richness and functional diversity were generally higher in pure and mixed stands of native F. sylvatica than in pure conifer stands, especially in comparison to non-native P. menziesii. These differences were particularly strong at the landscape scale. Pure conifer stands harbored only a reduced set of functionally similar bird species. Structural diversity based on tree microhabitat availability emerged as a key predictor of bird diversity. Synthesis and applications: Our study suggests that tree species mixtures do not necessarily increase bird diversity compared to pure stands of native trees, but can promote bird diversity relative to pure stands of species planted outside their natural range. Moreover, local mixtures, rather than a mosaic of pure stands, may promote bird diversity also at the landscape scale. By contrast, pure stands of tree species planted outside their natural range can increase the biotic homogenization of forest birds. Promoting structural diversity of microhabitats via tree retention and ensuring that non-native trees are planted in mixtures with native trees may alleviate potential limitations of climate change-oriented management for biodiversity.

Data from: A comprehensive evaluation of flowering plant diversity and conservation priority for national park planning in China

Establishment of a national park protection system in China, including the latest target proposed to protect at least 30% of the land area, calls for a comprehensive exploration of conservation priorities incorporating multiple diversity facets. We herein evaluate the spatial distribution of Chinese flowering plants from the perspectives of richness, uniqueness, vulnerability, and evolutionary history, by integrating three mega-phylogenies and comprehensive distribution data. We detect significantly high consistency among hotspots of different diversity measures for Chinese flowering plants, suggesting that multiple facets of evolutionary diversity are concentrically distributed in China. Affording legal protection to these areas is expected to maximize positive conservation outcomes. We propose two integrative diversity indices by incorporating three richness-based and three phylogeny-based measures, respectively. Both methods identify areas with high species richness, but the integrative phylogeny-based index also locates key areas with ancient and unique evolutionary histories (e.g., Ailao-Wuliang Mts, Dabie Mts, Hainan rainforest, Karst area of Yunnan-Guizhou-Guangxi, Nanling Mts, and southeast coastal regions). Of all the diversity indices explored, phylogenetic endemism maximizes the incidental protection of other indices in most cases, emphasizing its significance for conservation planning. Finally, 42 priority areas are identified by combining the 5%-criterion hotspots of two integrative indices and the minimum area to protect all threatened species analyzed. These priorities cover only 13.3% of China's land area but host 97.1% of species richness (23,394/24,095), 96.5% of endemic species (11,841/12,274), 100% of threatened species (2,613/2,613), and 99.3% of phylogenetic diversity for flowering plants involved in this study. These frameworks provide a solid scientific basis for national park planning in China.

Dryness weakens the positive effects of plant and fungal β diversities on above- and belowground biomass

Plant and microbial diversity are key to determine ecosystem functioning. Despite the well-known role of local-scale α diversity in affecting vegetation productivity, it still remains unclear about the effects of community heterogeneity (β diversity) of plants and soil microbes on above- and belowground productivity (AGB and BGB) across contrasting environments. Here, we conducted a dryness-gradient transect survey over 3000 km across grasslands on the Tibetan Plateau. We found that plant β diversity was more dominant than α diversity in stimulating AGB, while soil fungal β diversity was the key driver in enhancing BGB. However, these positive effects of plant and microbial β diversity on AGB and BGB were strongly weakened by increasing climatic dryness, mainly because higher soil available phosphorus caused by increasing dryness reduced both plant and soil fungal β diversities. Overall, these new findings highlight the critical role of above- and belowground β diversity in sustaining grassland productivity, raising our awareness to the ecological risks of large-scale biotic homogenization under future climate change.

opennotspecifiedMar 2016View details →

FIGURE 11 in Species discovery and diversity in Lobocriconema (Criconematidae: Nematoda) and related plant-parasitic nematodes from North American ecoregions

FIGURE 11. Light microscope images of female Lobocriconema sp. specimens from clade D. A, F, K (group 9), Nine-Mile Prairie, Nebraska, A) NID 1155, entire, 400X, F) NID 1156, head, 1000X, K) NID 1156, tail, 1000X. B, G, L) (group 11), Big Thicket National Preserve, Texas, B) NID 5647, entire, 400X, G) NID 5647, head, 1000X, L) NID 5653, tail, 1000X. C, H, M) (group 12), Tunica Hills, Louisiana, C) NID 3057, entire, 400X, H) NID 3057, head, 1000X, M) NID 3090, tail, 1000X. D, I, N) NID 3403 (group 13), Gregory Bald, Great Smoky Mountains National Park, North Carolina, D) entire, 400X, I) head, 1000X, N) tail, 1000X. E, J, O) NID 3297 (group 14), Torreya State Park, Florida, E) entire, 400X, J) head, 1000X, O) tail, 1000X.

opennotspecifiedMar 2016View details →

FIGURE 10. Neighbor-joining ITS1 in Species discovery and diversity in Lobocriconema (Criconematidae: Nematoda) and related plant-parasitic nematodes from North American ecoregions

FIGURE 10. Neighbor-joining ITS1 tree (Internal Transcribed Spacer 1). Terminal branches identified by NID numbers, taxon, location information and COI group. GenBank Accession sequences are highlighted in green, NID numbers from Criconema arkaense collection sites in Cordero et al. (2012) are highlighted in orange. Clade designation follows the COI tree structure. Red bootstrap values of 5,000 replications.