Plant species richness, endemism, and genetic resources in Namibia

Namibia is a floristically diverse, arid to mesic country, with several highly distinct taxa. Including naturalized plants, there are about 4334 vascular plant species and infraspecific taxa within the country's borders, a substantial increase from the existing major reference work. Dominant families are the Poaceae (422species), Fabaceae (377), Asteraceae (385) and Mesembryanthemaceae (177). Freshwater algae and most other groups of lower plants remain poorly known. Concentrations of plant species richness are found in the Succulent Karoo biome, Kaokoveld, Otavi highland/Karstveld area, Okavango Basin, and Khomas highlands. Recent studies have led to a new estimate of 687 endemic plant species, defined as those contained wholly within Namibia's borders, amounting to about 17% of the Namibian flora. At least a further 275 species are Namib Desert endemics shared between the Kaokoveld and southern Angola (75spp.) and between the Succulent Karoo and northwestern South Africa (200spp.). Research on plant genetic resources is focused on species of potential or actual agricultural importance, such as pearl millet, Pennisetum glaucum, and cucurbits. Many wild plants have considerable genetic diversity and development potential. Primary threats to plant diversity fall in the category of poor land management and inappropriate development.     

Inventory, differentiation, and proportional diversity: a consistent terminology for quantifying species diversity

Almost half a century after Whittaker (Ecol Monogr 30:279–338, 1960) proposed his influential diversity concept, it is time for a critical reappraisal. Although the terms alpha, beta and gamma diversity introduced by Whittaker have become general textbook knowledge, the concept suffers from several drawbacks. First, alpha and gamma diversity share the same characteristics and are differentiated only by the scale at which they are applied. However, as scale is relative––depending on the organism(s) or ecosystems investigated––this is not a meaningful ecological criterion. Alpha and gamma diversity can instead be grouped together under the term “inventory diversity.” Out of the three levels proposed by Whittaker, beta diversity is the one which receives the most contradictory comments regarding its usefulness (“key concept” vs. “abstruse concept”). Obviously beta diversity means different things to different people. Apart from the large variety of methods used to investigate it, the main reason for this may be different underlying data characteristics. A literature review reveals that the multitude of measures used to assess beta diversity can be sorted into two conceptually different groups. The first group directly takes species distinction into account and compares the similarity of sites (similarity indices, slope of the distance decay relationship, length of the ordination axis, and sum of squares of a species matrix). The second group relates species richness (or other summary diversity measures) of two (or more) different scales to each other (additive and multiplicative partitioning). Due to that important distinction, we suggest that beta diversity should be split into two levels, “differentiation diversity” (first group) and “proportional diversity” (second group). Thus, we propose to use the terms “inventory diversity” for within-sample diversity, “differentiation diversity” for compositional similarity between samples, and “proportional diversity” for the comparison of inventory diversity across spatial and temporal scales. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

山西关帝山森林群落物种、谱系和功能多样性海拔格局

探索和揭示生物多样性的空间格局和维持机制是生态学和生物地理学研究的热点内容, 但综合物种、系统进化和功能属性等方面的多样性海拔格局研究很少。该文以关帝山森林群落为研究对象, 综合物种、谱系和功能α和β多样性指数, 旨在初步探讨关帝山森林群落多样性海拔格局及其维持机制。研究结果表明: 随着海拔的升高(1 409-2 150 m), 关帝山森林群落物种丰富度指数(S)、谱系多样性指数(PD)和功能丰富度指数(FRic)整体上表现出上升的趋势, 特别是海拔1 800 m以上区域。随着海拔的升高, 总β多样性(β_total)和更替(β_repl)上升趋势明显, 而丰富度差异(β_rich)则逐渐下降。不同生活型植物的物种、谱系和功能多样性海拔格局差异较大。随着海拔的升高, 草本植物S和物种多样性指数(H′)上升趋势高于木本植物。影响草本植物S分布的主要因素是地形因子, 而影响木本植物S分布的主要因素是历史过程。随着海拔的升高, 木本植物β_total上升趋势要比草本植物明显。随着海拔的升高, 木本植物β_repl和β_rich分别表现出单峰格局和“U”形格局, 而草本植物β_repl和β_rich则分别表现出单调递增和单调递减的格局。随着环境差异和地理距离的增加, 群落间物种、谱系和功能β多样性显著增加。环境差异(环境过滤)对木本植物的β多样性具有相对较强的作用; 而环境差异(环境过滤)和地理距离(扩散限制)共同作用于草本植物的β多样性。     

Diversity and family: an inquiry into the effects of ethnic,linguistic, and religious fractionalization on family values

This article focuses on the connection between three forms of diversity – religious, ethnic, and linguistic – and family values. The article builds on the idea that diversity challenges social identity and people react by returning to traditional family values in order to protect their social identity and the in-group culture. The paper aims at contributing to the sociological debate about the effect of diversity on social life and investigates how different types of diversity connect with traditional family values because individuals want to protect their in-group culture that is mainly transmitted within family. The paper tests the research hypotheses employing multilevel regression models and using data from the ISSP IV from 2012. Religious diversity associates with traditional attitudes regarding marriage and gender roles, ethnic diversity goes together with lower support for marriage, but has no connection with attitudes towards gender role, while linguistic diversity is not associated with attitudes family values.     

Seasonal fire effects on the diversity patterns,spatial distribution and community structure of forbs in the Northern Mixed Prairie,USA

The effects of fire season on forb diversity patterns, density, and composition were determined for a northern Mixed Prairie site, USA. Repeated spring burns (dormant season), summer burns, fall burns (dormant season), and unburned treatments were compared over a 3-yr period characterized by wet and dry moisture conditions. Alpha and beta diversity were highest on unburned and summer burn treatments, while landscape mosaic diversity was highest on fall burns. Forb density was highest on fall and spring burn sites. Nine forb species comprised 82% of total densities and were significantly affected by fire season and year to year variations in moisture. Forb composition for unburned and spring burn treatments was similar, but both treatments were different from the summer burn and fall burn treatments which were similar to each other. Fire alone did not appear to be an intense enough disturbance to initiate drastic changes in the forb component of vegetation patches. Specific fire seasons did appear to either mask or enhance forb structure arising from other disturbance(s). Fire season also affected the scales of forb organization in the landscape. Contrasting spatial characteristics of the forb component of prairie plant communities may provide a diagnostic technique for exposing the interaction of disturbances at different temporal and spatial scales.     

Genomic and physiological diversity amongst strains of Thiobacillus ferrooxidans,and genomic comparison with Thiobacillus thiooxidans

Twenty-three strains of Thiobacillus ferrooxidans of known pedigree were examined. Thirteen strains survived 65° C for 5 min and 7 of these for 10 min, but sporulation was never observed. All strains grew between 25° C and 35° C and some strains grew at 5° and 40° C. They were genomically diverse, comprising 7 DNA homology groups, and the GC content varied from 55–65 mol %. Correlation between genomic group and growth temperature was noted. All strains grew on ferrous sulfate as energy source, but some failed to utilize elemental sulfur. Acidified thiosulfate supported growth of most of the strains examined but it was judged to be a poor substrate upon which to base taxonomic conclusions because of decomposition of thiosulfate in acid. Six strains of Thiobacillus thiooxidans showed negligible genomic affinity to T. ferrooxidans, and they comprised 2 DNA homology groups and their GC content varied from 52–62 mol%. Anomalies due to contaminants in cultures of T. ferrooxidans were resolved, and the contaminants were identified.     

Plant Diversity, Production, Stability, and Susceptibility to Invasion in Restored Northern Tall Grass Prairies (United States)

This study investigated the relationship among plant diversity, production, stability, and susceptibility to invasion in restored northern tall grass prairies (United States). The experiment consisted of 50 species mixtures fertilized with N or P, at high or low levels. Results from the past 5 years were as follows: (1) aboveground biomass increased and year‐to‐year variability declined with increases in plant species and functional form richness, mostly as a result of substantial increases in minimum biomass (maximum biomass was unaffected). (2) Aboveground biomass and biomass stability increased when the species in the mixture had: (a) high relative growth rates, root density, root surface area per unit of root biomass, uptake rates of N or P per unit of root surface area, and N use efficiency and (b) low root to shoot ratio. (3) Invasion of nonseeded species declined with increases in plant species and functional form richness. (4) The results from this experiment did not provide a single specific criterion for selecting an optimal species mixture. However, if the objectives of the restoration were simply to achieve an aboveground biomass variability that is less than that of growing‐season precipitation, then the seed mixtures need to have a minimum of nine species and three functional forms.     

Fish taxonomic,functional, and phylogenetic diversity and their vulnerabilities in the largest river in southeastern China

1. Freshwater biodiversity is currently under multiple threats. Conservation of freshwater fish biodiversity needs to be prioritized because natural conservation resources are always limited.
2. Samples were collected at 24 sites in the Min River, the largest basin in southeastern China. Taxonomic, functional, and phylogenetic diversity were analyzed. Biodiversity vulnerability was measured by removing one species each time out of the community with replacement.
3. Results suggested that hotspots for taxonomic and phylogenetic diversity were located at two impounded sites, while for functional diversity were those sites with no upstream dams. Little congruence was observed between taxonomic, functional, and phylogenetic diversity. Fragmentation of river network connectivity caused by dams was a significant factor affecting the biodiversity patterns. Beta turnover was the driving component for beta diversity, indicating that biodiversity dissimilarity along the river was mostly explained by environmental sorting. Fifteen out of 16 species that contributed the most to different facets of biodiversity were mostly endemic, either they had distinctive functional traits or they were the most prevalent species. Sites with the highest diversity vulnerability were characterized by these distinctive species. Functional diversity was more vulnerable to species loss comparing with the other two biodiversity facets.
4. Prioritizing those biodiversity hotspots, sites with extreme functional vulnerability, and those distinctive endemic species which contributed the most to biodiversity vulnerability is suggested in the Min River. The study found evidence that congruence among different facets of biodiversity is hard to achieve, and functional diversity is the most vulnerable in a freshwater system fragmented by intensive dam constructions. This work will help to develop systematic conservation planning from the perspective of different biodiversity facets.

     

Habitat isolation changes the beta diversity of the vascular epiphyte community in lower montane forest,Veracruz, Mexico

Habitat isolation is one of the most important factors endangering the biodiversity, but little research has been done with vascular epiphytes. In order to understand the effect of isolation on the epiphyte community, we studied epiphyte diversity on three plots in a forest fragment, two riparian forest fragments, and in isolated pastureland trees. We found 118 vascular epiphyte species. On forest plots, both epiphyte richness per tree (S_tree) and species turnover rate within trees (β_tree) registered the highest values, although the lowest S_tree diversity was also found there; additionally inside the forest were host species with clearly different epiphyte community. S_tree and β_tree diversities of riparian fragments behaved similarly to those of the forest. Isolated trees had the second highest S_tree diversity, although their β_tree diversity was the lowest. In the forest plots were both, the highest and lowest expected accumulated richness (α diversity); on riparian fragments it was intermediate, and the second lowest α diversity was registered for isolated trees. Species turnover rate among plots (β) was high and was associated with both, isolation and a distance gradient from permanent water sources. The epiphyte community on isolated trees was clearly different to the other habitats. Results suggest that deforestation eliminated dry areas and specific hosts that were important for the maintenance of epiphyte species richness. In pastureland trees the epiphyte β_tree diversity diminished, suggesting a simplification of the environment for epiphytes and causing a low α diversity.     

Climate change affects Galliformes taxonomic,phylogenetic and functional diversity indexes,shifting conservation priority areas in China

Aim

Comprehensive biodiversity protection necessitates the consideration of multiple indexes of diversity, and how the distribution patterns of priority areas may shift under climate change. Galliformes is a globally endangered avian order vulnerable to climate change that provide an important indicator for wildlife conservation effectiveness. Here, we identified priority areas for conserving Galliformes taxonomic, phylogenetic, and functional diversity in China and their spatial dynamics subject to climate change, and examined how well existing protected areas align with current and future priority areas.

Location

China.

Methods

We applied species distribution modelling and Zonation algorithms to identify conservation priority area dynamics for 47 galliform species across three biodiversity indexes subject to three future climate change scenarios to 2050s and 2070s. We overlaid these identified priority areas onto existing national nature reserves and national parks to assess and project their effectiveness.

Results

Current priority areas proved spatially incongruent between indexes, with an optimal area overlap comprising just 10.3% of China's land area, lying largely outside of existing protected areas. Furthermore, over 80% of modelled optimal priority areas currently lacked formal conservation status. Future priority areas will shift substantially under climate change, to an extent dependent on greenhouse gas emission scenarios. Nevertheless, we identified five large regions where optimal Galliformes diversity indexes should remain stable under all scenarios, thus providing potential climatic refugia, if protected from human encroachment.

Main Conclusions

The current deficits we identified for Galliformes protection in China resonate with a broader need for hierarchical conservation strategic planning across regions and ecosystems to ensure long-term biodiversity protection, accommodating for climate change.     

Avian malaria on Madagascar: prevalence,biodiversity and specialization of haemosporidian parasites

Previous studies about geographic patterns of species diversity of avian malaria parasites and others in the Order Haemosporida did not include the avian biodiversity hotspot Madagascar. Since there are few data available on avian malaria parasites on Madagascar, we conducted the first known large-scale molecular-based study to investigate their biodiversity. Samples (1067) from 55 bird species were examined by a PCR method amplifying nearly the whole haemosporidian cytochrome b gene (1063?bp). The parasite lineages found were further characterized phylogenetically and the degree of specialization was determined with a newly introduced host diversity index (Hd). Our results demonstrate that Madagascar indeed represents a biodiversity hotspot for avian malaria parasites as we detected 71 genetically distinct parasite lineages of the genera Plasmodium and Haemoproteus. Furthermore, by using a phylogenetic approach and including the sequence divergence we suspect that the detected haemosporidian lineages represent at least 29 groups i.e. proposed species. The here presented Hd values for each parasite regarding host species, genus and family strongly support previous works demonstrating the elastic host ranges of some avian parsites of the Order Haemosporida. Representatives of the avian parasite genera Plasmodium and Leucocytozoon tend to more often be generalists than those of the genus Haemoproteus. However, as demonstrated in various examples, there is a large overlap and single parasite lineages frequently deviate from this rule.     

新薛河底栖动物物种多样性与功能多样性研究

研究功能多样性与物种多样性关系及其随环境梯度的变化规律,有助于理解生物在群落中的共存机制;然而,二者间关系的研究在淡水生态学中尚鲜见报道。通过对新薛河典型河段(A缓流河段、B断流河段、C有机污染河段、D对照河段、E人为干扰河段)底栖动物季节性调查,就物种多样性和功能多样性时空动态及关系进行了研究。结果表明:在空间序列上,物种多样性指数在B河段均最低,表明间歇性断流对物种多样性影响重大。功能丰富度在D河段最高,A河段最低;功能均匀度在A河段高于其他河段;功能分离度在A、B河段最高,D河段最低。在时间序列上,物种丰富度和Shannon指数均值在10月份最低,4月份最高;均匀度指数在12月份最低,10月份最高。3个功能多样性指数于各季节间差异显著、相互独立,主要受水文条件和底栖动物生活史影响。相关分析表明,功能多样性指数间无显著相关性;功能丰富度同物种丰富度和Shannon指数相关显著,功能均匀度同物种均匀度相关显著。逐步回归分析发现,功能丰富度受物种丰富度和Shannon指数影响显著,功能均匀度受物种均匀度影响显著;功能多样性和物种多样性指数间拟合度总体不高。研究结果进一步表明:相对物种多样性,功能多样性对生境梯度变化响应更加全面。     

Functional traits explain waterbirds' host status,subtype richness,and community-level infection risk for avian influenza

Species functional traits can influence pathogen transmission processes, and consequently affect species' host status, pathogen diversity, and community-level infection risk. We here investigated, for 143 European waterbird species, effects of functional traits on host status and pathogen diversity (subtype richness) for avian influenza virus at species level. We then explored the association between functional diversity and HPAI H5Nx occurrence at the community level for 2016/17 and 2021/22 epidemics in Europe. We found that both host status and subtype richness were shaped by several traits, such as diet guild and dispersal ability, and that the community-weighted means of these traits were also correlated with community-level risk of H5Nx occurrence. Moreover, functional divergence was negatively associated with H5Nx occurrence, indicating that functional diversity can reduce infection risk. Our findings highlight the value of integrating trait-based ecology into the framework of diversity–disease relationship, and provide new insights for HPAI prediction and prevention.     

The components of biodiversity,with a particular focus on phylogenetic information

We present a framework for biodiversity metrics that organizes the growing panoply of metrics. Our framework distinguishes metrics based on the type of information–abundance, phylogeny, function–and two common properties–magnitude and variability. Our new metrics of phylogenetic diversity are based on a partition of the total branch lengths of a cladogram into the proportional share of each species, including: a measure of divergence which standardizes the amount of evolutionary divergence by species richness and time depth of the cladogram; a measure of regularity which is maximal when the tree is perfectly symmetrical so that all species have the same proportional branch lengths; a measure that combines information on the magnitude and variability of abundance with phylogenetic variability, and a measure of phylogenetically weighted effective mean abundance; and indicate how those metrics can be decomposed into α and β components. We illustrate the utility of these new metrics using empirical data on the bat fauna of Manu, Peru. Divergence was greatest in lowland rainforest and at the transition between cloud and elfin forests, and least in upper elfin forests and in cloud forests. In contrast, regularity was greatest in lowland rainforest, dipping to its smallest values in mid‐elevation cloud forests, and then increasing in high elevation elfin forests. These patterns indicate that the first species to drop out with increasing elevation are ones that are closely related to other species in the metacommunity. Measures of the effective number of phylogenetically independent or distinct species decreased very rapidly with elevation, and β‐diversity was larger. In contrast, a comparison of feeding guilds shows a different effect of phylogenetic patterning. Along the elevational gradient, each guild generally loses some species from each clade–rather than entire clades–explaining the maintenance of functional diversity as phylogenetic diversity decreases.     

放牧干扰下高寒草甸物种、生活型和功能群多样性与生物量的关系

为明晰放牧强度对高寒草甸物种、生活型以及功能群多样性和生物量的时间累积作用以及对多样性与生物量之间相互关系的影响。选择青藏高原东北缘高寒草甸,在6个放牧强度样地连续4 a(2012—2015)进行物种、生活型、功能群多样性和生物量调查。采用重复测量方差分析和线性回归法分析放牧强度和放牧年份对物种、生活型、功能群多样性以及多样性与生物量之间的相关关系的影响。结果表明:(1)放牧强度和放牧年份均对生物量产生显著影响。随放牧强度增加,生物量显著降低。但随放牧年份延长,不同放牧强度区生物量无一致的变化规律。(2)放牧年份对物种、生活型和功能群丰富度、均匀度和优势度的影响均达到显著水平。但放牧强度和放牧年份只对物种丰富度产生交互作用,放牧强度对物种丰富度的影响具有时间的累积效应。(3)放牧干扰下不同层次多样性,仅物种丰富度与所有多样性指数显著相关,物种丰富度可以作为物种多样性测度的代表性指标。(4)多样性与生物量关系的研究,对丰富度而言,仅低放牧强度样地(Plot2)中物种丰富度随生物量增加而显著降低,其余放牧强度样地的物种、生活型和功能群丰富度均与生物量无关。对均匀度而言,高放牧强度样地(Plot4、Plot5、Plot6)生活型均匀度随生物量的增加而显著降低。对优势度而言,高放牧强度样地生活型优势度随生物量的增加而显著增加。生活型多样性可作为放牧干扰下生物量变化快速预测的有效指标。     

Differential responses of soil bacteria,fungi, archaea and protists to plant species richness and plant functional group identity

Plants are known to influence belowground microbial community structure along their roots, but the impacts of plant species richness and plant functional group (FG) identity on microbial communities in the bulk soil are still not well understood. Here, we used 454‐pyrosequencing to analyse the soil microbial community composition in a long‐term biodiversity experiment at Jena, Germany. We examined responses of bacteria, fungi, archaea, and protists to plant species richness (communities varying from 1 to 60 sown species) and plant FG identity (grasses, legumes, small herbs, tall herbs) in bulk soil. We hypothesized that plant species richness and FG identity would alter microbial community composition and have a positive impact on microbial species richness. Plant species richness had a marginal positive effect on the richness of fungi, but we observed no such effect on bacteria, archaea and protists. Plant species richness also did not have a large impact on microbial community composition. Rather, abiotic soil properties partially explained the community composition of bacteria, fungi, arbuscular mycorrhizal fungi (AMF), archaea and protists. Plant FG richness did not impact microbial community composition; however, plant FG identity was more effective. Bacterial richness was highest in legume plots and lowest in small herb plots, and AMF and archaeal community composition in legume plant communities was distinct from that in communities composed of other plant FGs. We conclude that soil microbial community composition in bulk soil is influenced more by changes in plant FG composition and abiotic soil properties, than by changes in plant species richness per se.     

利用PLFA、CLPPs和ARDRA标记分析甲胺磷对土壤微生物群落的影响

利用磷脂脂肪酸(PLFA)、群落水平生理活性(CLPPs)和扩增核糖体DNA限制性分析(ARDRA)标记,综合评估低浓度和高浓度甲胺磷连续施用2和4 yr后对土壤微生物群落结构、功能和遗传多样性的影响。结果表明,甲胺磷胁迫使土壤微生物生物量减少而细菌(革兰氏阴性菌)数量增加,同时使微生物群落功能多样性下降而遗传多样性提高;处理2 yr后高浓度甲胺磷胁迫对微生物群落的影响较低浓度胁迫更为明显,处理4 yr后两个浓度胁迫则具有相似的显著影响,表明不同浓度甲胺磷的长期胁迫均能对微生物群落造成严重破坏。     

毛乌素沙地植被不同恢复阶段植物群落物种多样性、功能多样性和系统发育多样性

进入21世纪以来, 中国荒漠化恢复取得显著成效, 荒漠化、沙化土地面积持续减少, 植被覆盖度大幅提升, 但关于植被恢复过程中生物多样性如何变化的研究不足, 这制约着对荒漠化恢复成效的全面评估。本文基于群落调查和叶功能性状(叶片厚度、叶片干物质含量、比叶面积和叶片密度)的测定, 分析了毛乌素沙地不同恢复阶段(半固定沙地、固定沙地、结皮覆盖沙地和草本植物覆盖沙地)的植物群落物种多样性、功能多样性和系统发育多样性特征。结果表明: (1)多数叶功能性状的系统发育信号不显著, 表明环境因子对研究区植物功能性状的塑造作用很强。(2)对于α多样性, 结皮覆盖沙地的物种多样性(Shannon-Wiener多样性, H)、物种丰富度(S)、功能丰富度(FRic)及系统发育多样性(PD)指数均显著低于其他恢复阶段, 而其他3个阶段间无显著差异; 这些指数间均显著正相关, 表明物种多样性、功能多样性和系统发育多样性在植被恢复过程中协同变化。(3) β多样性指数随恢复阶段间隔增加而逐渐增大, 表明物种组成、功能属性及系统发育关系随植被恢复持续变化, 且半固定沙地到固定沙地的群落物种组成、功能属性及系统发育关系更替最快, 导致群落间差异最大。(4)固定沙地、结皮覆盖沙地和草本植物覆盖沙地群落系统发育结构均趋向于发散, 表明竞争排斥是群落构建的主要驱动力; 而半固定沙地群落系统发育结构无一致规律, 表明群落构建可能受到生境过滤和竞争排斥的综合作用。研究结果可为植被建设与管理提供参考, 为毛乌素沙地生态保育和生物多样性的保护提供科学依据。