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opencc-zeroAug 2020View details →

Data from: Phylogenomic approaches reveal how climate shapes patterns of genetic diversity in an African rain forest tree species

The world's second largest expanse of tropical rain forest is in Central Africa and it harbours enormous species diversity. Population genetic studies have consistently revealed significant structure across central African rain forest plants, in particular a North-South genetic discontinuity around the equatorial line, in a continuous expanse of rain forest but where a climatic inversion is documented. Here, we took a phylogeographic approach by sequencing 351 nuclear markers in 112 individuals across the distribution of the African rain forest tree species Annickia affinis (Annonaceae). We showed for the first time that the North-South divide is the result of a single, major colonisation event across the climatic inversion from an ancestral population located in Gabon. We suggested that differences in ecological niche of populations located on either side of this inversion may have contributed to this phylogenetic discontinuity. We found evidence for inland dispersal, predominantly in northern areas, and variable demographic histories among genetic clusters, indicating that populations responded differently to past climate change. We show how newly-developed genomic tools can provide invaluable insights into our understanding of tropical rain forest evolutionary dynamics.

opencc-zeroAug 2020View details →

Diversity and conservation of saproxylic beetles in 42 European tree species: an experimental approach using early successional stages of branches

Correction: In the original version of this dataset, the non‐native Prunus serotina was incorrectly interchanged with the native Prunus padus, and eight individuals of saproxylic beetles were incorrectly removed from the data when splitting beetles in saproxylic and non‐saproxylic species. The correct tree species is Prunus serotina, and results refer to a total of 113 species of saproxylic beetles and 30,550 individuals. 1. Tree species diversity is important to maintain saproxylic beetle diversity in managed forests. However, knowledge about the conservational importance of single tree species and implications for forest management and conservation practices are lacking. 2. We exposed freshly cut branch-bundles of 42 tree species, representing tree species native and non-native to Europe, under sun-exposed and shaded conditions for one year. Afterwards, communities of saproxylic beetles were reared ex-situ for two years. We tested for the impact of tree species and sun exposure on alpha-, beta-, and gamma diversity as well as composition of saproxylic beetle communities. 3. Tree species had a lower impact on saproxylic beetle communities compared to sun exposure. The diversity of saproxylic beetles varied strongly among tree species, with highest alpha- and gamma-diversity found in Quercus petraea. Red-listed saproxylic beetle species occurred ubiquitously among tree species. We found distinct differences in the community composition of broadleaved and coniferous tree species, native and non-native tree species as well as sun-exposed and shaded deadwood. 4. Our study enhances the understanding of the importance of previously understudied and non-native tree species for the diversity of saproxylic beetles. To improve conservation practices for saproxylic beetles and especially red-listed species, we suggest a stronger incorporation of tree species diversity and sun exposure into forest management strategies, including the enrichment of deadwood from native tree species and with a specific focus on locally rare or silvicultural less important tree species.

Parallel responses of species diversity and functional diversity to changes in patch size are driven by distinct processes

1. Do species and functional trait diversity respond similarly to deterministic and random processes? Theory predicts that the contributions of random and deterministic processes to species diversity depend on patch size. Smaller patches are more strongly influenced by random sampling effects, by having fewer individuals, as well as ecological drift, which propagates the effects of small samples through stochastic birth and death processes. These random processes decrease species richness and increase compositional differences among small patches. Larger patches are predicted to be more deterministically assembled, with greater species richness and greater predictability of composition for a particular environment. The consequences of patch size for the diversity of functional traits, however, are poorly understood. Species diversity may be a poor proxy for functional diversity due to trait redundancies among species, making it unclear how random and deterministic processes alter functional diversity within patches of differing size, and how these differences scale up to determine among-patch functional diversity. 2. We report a novel experimental study of species and functional diversity across spatial scales. We manipulated patch area in an experimental plant metacommunity and used a nested sampling design to distinguish the effects of deterministic processes, ecological drift, and sampling effects on species and functional trait diversity. 3. Our study revealed a pervasive influence of ecological drift and sampling effects on diversity, with distinct influences on functional traits and species composition within and among patches. Overall, drift and sampling effects caused a 2- to 3-fold decrease in the importance of deterministic processes in small fragments. Species and functional diversity showed similar patterns with patch size: larger patches had greater within-patch (alpha) diversity and lower among-patch (beta) diversity, consistent with theory. However, our nested sampling design revealed that sampling effects (i.e. the size of the sample area) largely determined alpha species diversity and beta functional diversity, while ecological drift had a stronger influence on alpha functional diversity and beta species diversity. 4. Synthesis. The compositions of species and functional diversity in a community are influenced by distinct processes, resulting in divergent spatial scaling of species and their traits within patches and across landscapes.

Data from: Exotic species drive patterns of plant species diversity in 93 restored tallgrass prairies

A primary goal of restoration ecology is to understand the factors that generate variability in species diversity and composition among restorations. Plant communities may assemble deterministically towards a common community type, or they may assemble stochastically, ending differently because of weather conditions during establishment, soil legacy effects, or exotic species propagule pressure. To test these alternative hypotheses, we sampled plant communities and soil at 93 randomly selected restored prairies distributed throughout Iowa, USA. Five remnant sites were sampled as a reference. We tested our hypotheses using multiple regressions and investigated the strength of direct and indirect effects on species diversity and richness using structural equation models. The prairie restorations were highly variable in their age, size, diversity, soil characteristics, and how they were managed post-seeding. The strongest predictor of plant species richness and diversity was the degree of invasion, as measured by the abundance of exotic species. Restorations planted with species-rich seed mixes had reduced exotic species abundance, which led indirectly to higher species richness of restorations. Sites with higher organic matter and a more linear shape had a direct positive effect on exotic abundance, which in turn decreased diversity. We found little support for deterministic assembly, and diversity did not increase with the age of planting. Our results indicate that restored prairie communities tend to assemble into states of high or low diversity, driven by invasion from exotic plant species. Management of exotic species is essential for maximizing species diversity in temperate grassland restorations.

opencc-by-4.0Sep 2020View details →

Data from: Contrasting vulnerability of monospecific and species-diverse forests to wind and bark beetle disturbance: The role of management

The published dataset contains the results of the paper titled Contrasting vulnerability of monospecific and species-diverse forests to wind and bark beetle disturbance: The role of management, in Ecology and Evolution. Results are based on the output of the model iLand (http://iland.boku.ac.at/startpage). contact: Laura Dobor; dobor.laura@gmail.com

Supplementary material 1 from: Huang J, Guo Z, Tang S, Ren W, Chu G, Wang L, Zhao L, Yu R, Xu Y, Ding Y, Zang R (2020) Floristic composition and plant diversity in distribution areas of native species congeneric with Betula halophila in Xinjiang, northwest China. Nature Conservation 42: 1-17. https://doi.org/10.3897/natureconservation.42.54735

Figure S1. The correlation between environmental variables in distribution areas of five congeneric species with Betula halophila

FIGURE 4 in The unknown diversity of the genus Characidium (Characiformes: Crenuchidae) in the Chocó biogeographic region, Colombian Andes: Two new species supported by morphological and molecular data

FIGURE 4 Scale detail of C. tatama n. sp. IMCN 8924, Paratype, 36.3 mm LS, white arrows show the rounded point characteristic in the lateral line

FIGURE 2 in The unknown diversity of the genus Characidium (Characiformes: Crenuchidae) in the Chocó biogeographic region, Colombian Andes: Two new species supported by morphological and molecular data

FIGURE 2 Ultrametric tree using BEAST representing the phylogenetic relationships of the genus Characidium using COI sequences. Branch lengths were adjusted to a strict molecular clock. The black bars represent the UTOs obtained with the ABGD, GMYC and bPTP molecular delimitation methods and the majority consensus. Green dots posterior probability (>0.95)

FIGURE 1 in The unknown diversity of the genus Characidium (Characiformes: Crenuchidae) in the Chocó biogeographic region, Colombian Andes: Two new species supported by morphological and molecular data

FIGURE 1 Distribution map of the Characidium genus in the trans- Andean and cis-Andean regions of Colombia. Black triangle (HT)/yellow cicle, C. tatama n. sp.; red triangle (HT)/orange circle, C. dule n. sp.; red diamond, C. caucanum; red circle, C. phoxocephalum; white red mark (HT)/ purple circle, C. chancoense; white circle, C. cf. boavistae; blue diamond, C. cf. zebra; red-black star (HT)/grey circle, C. santcjohanni; HT, holotype

FIGURE 3 C. tatama n in The unknown diversity of the genus Characidium (Characiformes: Crenuchidae) in the Chocó biogeographic region, Colombian Andes: Two new species supported by morphological and molecular data

FIGURE 3 C. tatama n. sp., Holotype, IMCN 8925, 38.1 mm LS, Colombia, Chocó, San José Del Palmar. Scale bar = 1 cm

FIGURE 7 in The unknown diversity of the genus Characidium (Characiformes: Crenuchidae) in the Chocó biogeographic region, Colombian Andes: Two new species supported by morphological and molecular data

FIGURE 7 Detail of the composition of spots in C. dule n. sp. IMCN 8929, Paratype 38.24 mm LS, arrows show the detail. Scale bar = 1 cm

Data from: The impact of anthropogenic disturbances on the genetic diversity of terrestrial species: a global meta-analysis

Duplicate of 10.5061/dryad.6hdr7sqxq Human activities are primarily responsible for habitat loss and changes in natural environments around the world. It has been suggested that populations inhabiting human-modified landscapes experience reduced gene flow, inbreeding depression, and loss of alleles due to genetic drift. However, the empirical evidence shows contrasting effects of anthropogenic disturbances on the genetic diversity of species. We performed a meta-analysis of 61 studies that compared the genetic diversity of plant and/or animal populations in disturbed and more preserved areas (316 paired comparisons) to investigate the genetic responses to different disturbance types. There is a negative effect (effect size: -0.45; 95% CI: -0.61, -0.29) of disturbances on genetic diversity, in which the most detrimental effects are caused by the loss of connectivity and forest cover. The methodological approach can explain part of the heterogeneity among the genetic responses detected by primary studies: (i) studies using the number of effective alleles did not detect genetic erosion, while all other indices, revealed negative responses to disturbances; and (ii) only studies performed with transferred or a combination of transferred and specific microsatellites detected negative responses. The effects on animal populations are more detrimental than in plant populations. Only plant species with shrub life form, self-incompatible reproductive systems, and biotic pollination and seed dispersal, showed negative responses to disturbances. Despite all heterogeneity among studies, there is an overall negative effect of disturbances on the genetic diversity, which indicates that remaining populations inhabiting human-modified landscapes have reduced evolutionary potential and are prone to local extinction.

Data from: Helianthus maximiliani and species fine-scale spatial pattern affect diversity interactions in reconstructed tallgrass prairies

1. Biodiversity and Ecosystem Function analyses aim to explain how individual species and their interactions affect ecosystem function. With this study we asked in what ways do species interact, are these interactions affected by species planting pattern, and are initial (planted) proportions or previous year (realized) proportions a better reference point for characterizing grassland diversity effects? 2. We addressed these questions with experimental communities compiled from a pool of 16 tallgrass prairie species. We planted all species in monocultures and mixtures that varied in their species richness, evenness, and spatial pattern. We recorded species-specific biomass production over three growing seasons and fitted Diversity-Interactions (DI) models to annual plot biomass yields. 3. In the establishment season, all species interacted equally to form the diversity effect. In years 2 and 3, each species contributed a unique additive coefficient to its interaction with every other species to form the diversity effect. These interactions were affected by H. maximiliani and the species planting pattern. Models based on species planted proportions better-fit annual plot yields than models based on species previous contributions to plot biomass. 4. Outcomes suggest that efforts to plant tallgrass prairies to maximize diversity effects should focus on the specific species present and in what arrangement they are planted. Furthermore, for particularly diverse grasslands, the effort of collecting annual species biomass data may not be necessary when quantifying diversity effects with Diversity-Interactions models.

opencc-zeroNov 2020View details →

An invasive grass species has both local and broad-scale impacts on diversity: Potential mechanisms and implications

Questions The impact of invasive plant species on native diversity varies with spatial scale, with some invaders leading to broad-scale diversity declines and others only local declines. These discrepancies may reflect the invaders capacity to reduce niche opportunities across spatial scales which can be associated with their functional traits. We investigated impact-scale relationships and trait-based mechanisms, in areas invaded by the exotic perennial grass species, Bothriochloa pertusa. We examine root traits specifically, as belowground competition was considered particularly important to the success of this species. Location Grassy 'ironbark' woodlands of eastern Queensland, Australia Methods We examined plots with varying degrees of invasion by B. pertusa, at multiple spatial scales (up to 1000 m2) and analysed changes to the species area relationships (SARs) with increasing invader cover. Changes to SARs were assessed in relation to the invaders effect on rare (low-patch-occupancy) and common species in the community. In a separate analysis within the same habitat we collected root cores across a gradient of invader cover and analysed changes to community root traits that were considered important correlates of competition for space and nutrients. Results Invasion-induced reductions in diversity were pervasive at all scales investigated, and this was associated with a proportionally greater effect on rare species in the community. In the separate root analysis, changes in community root traits with increasing invader cover were potentially indicative of more intense competition for resources rather than space. Conclusions The observed regional-scale dominance of B. pertusa and associated declines in diversity warrant serious concern for the conservation of native plant communities and species in a region already at risk from other anthropogenic threats. Intense competition for belowground resources is likely a contributing mechanism to the success of B. pertusa in this study system. Experimental examination of this and other mechanisms would help to validate these findings.

opencc-by-4.0Dec 2020View details →

Dataset used for the submitted manuscript "The hump-shaped effect of plant functional diversity on the biological control of a multi-species pest community"

Dataset

FIGURE 10 in Description of two new Proceroecia species (Ostracoda: Halocyprididae) from neritic waters off South Korea with an insight into the morphological and molecular diversity of the genus

FIGURE 10. Phylogenetic tree of Proceroecia species reconstructed using Bayesian Inference. Numbers above branches represent posterior probability; roman numbers represent clades; GenBank numbers are in front of the species names.

FIGURE 8 in Description of two new Proceroecia species (Ostracoda: Halocyprididae) from neritic waters off South Korea with an insight into the morphological and molecular diversity of the genus

FIGURE 8. Line drawings of Proceroecia joseondonghaensis sp. nov. A, B, female; C, D, male: A—mandible; B—ventrodistal seta on the basis of mandible; C—mandible; D—sixth limb.

FIGURE 7 in Description of two new Proceroecia species (Ostracoda: Halocyprididae) from neritic waters off South Korea with an insight into the morphological and molecular diversity of the genus

FIGURE 7. Line drawings of Proceroecia joseondonghaensis sp. nov., female: A—carapace; B—first antenna and frontal organ; C—protopodite of the second antenna; D—fifth limb; E—endopodite of the second antenna; F—sixth limb; G—uropodal lamellae.

FIGURE 4 in Description of two new Proceroecia species (Ostracoda: Halocyprididae) from neritic waters off South Korea with an insight into the morphological and molecular diversity of the genus

FIGURE 4. Line drawings of Proceroecia hwanghaensis sp. nov., female: A—carapace; B—endopodite of the second antenna; C—maxilla; D—first antenna and frontal organ; E—protopodite of the second antenna; F—uropodal lamellae.

FIGURE 3 in Description of two new Proceroecia species (Ostracoda: Halocyprididae) from neritic waters off South Korea with an insight into the morphological and molecular diversity of the genus

FIGURE 3. SEM photographs: A, B—Proceroecia hwanghaensis sp. nov., female; C—P. joseondonghaensis sp. nov., male; A—right valve, external view; B—right valve postero-dorsal view; C—detail of the postero-dorsal spine on the right valve. The arrow indicates the position of the right asymmetrical gland.