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The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogues. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographical heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.

The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide here a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogues. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographic heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.

Tropical and subtropical forest ecosystems play an important role in the global carbon regulation. Although positive relationships between biodiversity and soil organic carbon (SOC) storage have been found in experimental grasslands, biodiversity effects on SOC storage in natural forests remain debated. Based on a large dataset from 523 forest inventory plots across subtropical forests in China, we tested the relationship between biodiversity and SOC storage and examined whether environmental conditions (temperature, precipitation, soil properties) and litter quantity (leaf litter and root biomass) and quality (leaf litter carbon to nitrogen ratio [leaf litter C/N]) had effects on SOC storage. Furthermore, we used linear mixed-effects models to test the relative effects of biodiversity, environmental conditions, and litter quantity and quality on SOC storage. We used structural equation models to test how these variables directly or indirectly affected SOC storage. We found that species diversity, together with climatic factors (mean annual temperature and mean annual precipitation), leaf litter C/N and root biomass determined SOC storage in subtropical forests at a large spatial scale. SOC storage was most strongly affected by climatic factors, followed by leaf litter C/N. Species diversity had both direct and indirect (through root biomass and leaf litter C/N) effects on SOC storage after accounting for environmental conditions. We also found that the positive diversity–SOC storage relationships were stronger in low and medium mean annual precipitation. Our findings highlight that higher species diversity can lead to higher SOC storage and therefore the conservation of biodiversity could play an important role in climate change mitigation.

Scalable ranking approaches can map effective biodiversity and climate targets for national conservation action by 2030., To achieve the goals of the post-2020 global biodiversity framework, we must identify representative targets that effectively protect biodiversity and can be implemented at a national level. We developed a framework to identify synergies between biodiversity and carbon across the Asian region and proposed a stepwise approach based on scalable priorities at regional, biome, and national levels that can complement potential Convention on Biological Diversity targets of protecting 30% land in the post-2020 global biodiversity framework. Our targets show that 30% of Asian land could effectively protect over 70% of all assessed species relative to only 11% now (based on analysis of 8932 terrestrial vertebrates), in addition to 2.3 to 3.6 hundred billion metric tons of carbon. Funding mechanisms are needed to ensure such targets to support biodiversity-carbon mutually beneficial solutions at the national level while reflecting broader priorities, especially in hyperdiverse countries where priorities exceed 30% of land.

The decline in species richness at higher latitudes is among the most fundamental patterns in ecology. Whether changes in species composition across space (beta-diversity) contribute to this gradient of overall species richness (gamma-diversity) remains hotly debated. Previous studies that failed to resolve the issue suffered from a well-known tendency for small samples in areas with high gamma-diversity to have inflated measures of beta-diversity. Here, we provide here a novel analytical test, using beta-diversity metrics that correct the gamma-diversity and sampling biases, to compare beta-diversity and species packing across a latitudinal gradient in tree species richness of 21 large forest plots along a large environmental gradient in East Asia. We demonstrate that after accounting for topography and correcting the gamma-diversity bias, tropical forests still have higher beta-diversity than temperate analogs. This suggests that beta-diversity contributes to the latitudinal species richness gradient as a component of gamma-diversity. Moreover, both niche specialization and niche marginality (a measure of niche spacing along an environmental gradient) also increase towards the equator, after controlling for the effect of topographic heterogeneity. This supports the joint importance of tighter species packing and larger niche space in tropical forests while also demonstrating the importance of local processes in controlling beta-diversity.

Although trees are key to ecosystem functioning, many forests and tree species across the globe face strong threats. Preserving areas of high biodiversity is a core priority for conservation; however, different dimensions of biodiversity and varied conservation targets make it difficult to respond effectively to this challenge. Here, we (i) identify priority areas for global tree conservation using comprehensive coverage of tree diversity based on taxonomy, phylogeny, and functional traits; and (ii) compare these findings to existing protected areas and global biodiversity conservation frameworks. We find that ca. 51% of the top-priority areas for tree biodiversity are located in current protected areas. The remaining half top-priority areas are subject to moderate to high human pressures, indicating conservation actions are needed to mitigate these human impacts. Our findings emphasize the effectiveness of using tree conservation priority areas for future global conservation planning.

Significance Human activities can drive both species’ range contractions and expansions. Species’ responses to human activities are suggested to be influenced by their geographic range sizes. Here, we test the idea that human impacts cause range declines in small-range species but promote range expansion of common species, using distribution data for 9,701 plants across China to examine the relation of human activities to the degree to which species fill their climatic potential ranges. We found that narrow-ranged and widespread species indeed exhibited opposing responses to human activities, with their range filling decreasing and increasing with human influence, respectively. These findings suggest that human activities have reduced ranges of narrow-ranged species but expanded those of widespread species, causing biotic homogenization across China., Human activities have shaped large-scale distributions of many species, driving both range contractions and expansions. Species differ naturally in range size, with small-range species concentrated in particular geographic areas and potentially deviating ecologically from widespread species. Hence, species’ responses to human activities may be influenced by their geographic range sizes, but if and how this happens are poorly understood. Here, we use a comprehensive distribution database and species distribution modeling to examine if and how human activities have affected the extent to which 9,701 vascular plants fill their climatic potential ranges in China. We find that narrow-ranged species have lower range filling and widespread species have higher range filling in the human-dominated southeastern part of China, compared with their counterparts distributed in the less human-influenced northwestern part. Variations in range filling across species and space are strongly associated with indicators of human activities (human population density, human footprint, and proportion of cropland) even after controlling for alternative drivers. Importantly, narrow-ranged and widespread species show negative and positive range-filling relationships to these human indicators, respectively. Our results illustrate that floras risk biotic homogenization as a consequence of anthropogenic activities, with narrow-ranged species becoming replaced by widespread species. Because narrow-ranged species are more numerous than widespread species in nature, negative impacts of human activities will be prevalent. Our findings highlight the importance of establishing more protected areas and zones of reduced human activities to safeguard the rich flora of China.

Aim: Geographical variation of range size is thought to be linked to climate seasonality and Quaternary glacial-interglacial oscillations. In addition, the importance of long-term climate stability is expected to be modulated by species' migration abilities. For plants, growth forms integrate traits that affect migration ability. Hence, we assess the relative importance of short- and long-term climate stability for range size patterns in plants and whether long-term stability is more important for more poorly migrating growth forms. Location: China. Time period: Last 21 ka. Major taxa studied: Vascular plants. Methods: A dataset including > 30,000 vascular plants was used to quantify geographical patterns of range size across China for all species and for eight growth forms separately. Spatial and non-spatial regressions with information-theoretical multi-model selection were performed to estimate the explanatory importance of climate seasonality and climate-change velocity from the Last Glacial Maximum to the present. The proportion of endemism for each growth form was also calculated. Results: Large geographical range sizes were generally observed in regions with strong climate seasonality and high climate-change velocity. The association between range size and velocity was stronger for perennial herbs and shrubs than for ferns, annual herbs, climbers and trees and stronger for small than for large trees; that is, more important for the growth forms with lower migration capacities. In line with this interpretation, growth forms strongly influenced by velocity also tend to have high proportions of endemism, which is also consistent with a relatively low ability to migrate. Main conclusions: Range size patterns of vascular plants in China are shaped by both climate seasonality and long-term climate stability, even though the region had a relatively mild influence from the Pleistocene glaciations, with a stronger influence of palaeoclimate stability on more poorly migrating groups. The differential influences of palaeoclimate stability across growth forms suggest that it needs further attention in research and management and that different growth forms are likely to respond in different ways to future climate changes.

Tropical and subtropical forest ecosystems play an important role in the global carbon regulation. Despite increasing evidence for effects of biodiversity (species diversity, functional diversity and functional dominance), stand structural attributes, stand age and environmental conditions (climate and topography) on tree carbon storage, the relative importance of these drivers at large scale is poorly understood. It is also still unclear whether biodiversity effects on tree carbon storage work through niche complementarity (i.e. increased tree carbon storage due to interspecific resource partitioning) or through the mass-ratio effect (tree carbon storage regulated by dominant traits within communities). Here we analyze tree carbon storage and its drivers using data of 480 plots sampled across subtropical forests in China. We use multiple regression models to test the relative effects of biodiversity, stand structural attributes, stand age and environmental conditions on tree carbon storage, and use a partial least squares path model to test how these variables directly and/or indirectly affect tree carbon storage. Our results show that tree carbon storage is most strongly affected by stand age, followed by climate, biodiversity and stand structural attributes. Stand age and climate had both direct and indirect (through species diversity, functional dominance and stand structural attributes) effects. We find that tree carbon storage correlates with both species diversity and functional dominance after stand age and environmental drivers are accounted for. Our results suggest that niche complementarity and the mass-ratio effect, not necessarily mutually exclusive, both play a role in maintaining ecosystem functioning. Our results further indicate that biodiversity conservation might be an effective way for enhancing tree carbon storage in natural, species-rich forest ecosystems.

With the development of biodiversity informatics, more and more data repositories have emerged, providing massive stores of open scientific data. The use of open data is increasingly valuable for scientific research and related decision making but little is known about which topics are addressed, especially in non-English publications. Further, how this data should be cited has been called into question. The Global Biodiversity Information Facility (GBIF) is the world’s largest and most widely-used open data access platform on the occurrence of species in nature. Here, we analyze the use of GBIF-mediated data in Chinese language publications. From 623 publications containing the word “GBIF”, we obtained 324 peer-reviewed publications. Among these publications, there were 237 journal papers, 17 doctoral theses, 66 master theses, and 4 conference papers. The publications came from 114 journals and 49 research institutes and universities. We found that the most common topics addressed by these publications were species distribution, climate change, biological invasion and medicinal plants. For data citation, multiple forms coexist. 295 publications (90% of publications) only cited the name of “GBIF” in the main text, without a Digital Object Identifier (DOI). Among the 29 publications that cited GBIF in the references, 17 cited the GBIF website, 8 publications listed the URL of a species page in GBIF, and only 4 publications cited a DOI, which is what GBIF recommends. Based on a discussion on the use of GBIF-mediated data and the resulting data citation issues, this study makes three suggestions to improve data citation practice, which are applicable to data citation practice in other non-English publications.

Aim Variation in species composition among sites (β-diversity) generally decreases with increasing latitude, but the underlying mechanisms are ambiguous. Although both local and large-scale processes may drive this pattern, they act all through influencing species abundance distribution (SAD) and spatial pattern of species. A null model incorporating SAD is often used to calculate expected β-diversity, which accounts for most variation in β-diversity. However, a recent study has shown that the deviation of observed β-diversity from expected values (β-deviation) increases with latitude. The latitudinal gradients in β-deviation may be related to both latitudinal differences in SADs and the degrees of spatial aggregation. Our study aims to (1) investigate how β-deviation varies with SAD and spatial aggregation, and (2) separate the contributions of SAD and aggregation in explaining latitudinal gradients in β-deviation. Location Global. Methods 197 forest plots (each containing 10 subplots) distributed along latitudinal gradients were used. Two β-diversity models were derived for communities with randomly and nonrandomly distributed species. The two models were used to simulate relationships of β-deviation with SAD and aggregation, and to separate the contributions of these two factors in explaining latitudinal gradients in β-deviation. Results β-deviation increased with the degree of aggregation and peaked at intermediate species abundance. The fraction of β-deviation linked to SAD increased with latitude in global and regional analyses, whereas the fraction of β-deviation linked to aggregation was only significantly correlated with latitude in New World south. The degree of aggregation increased with latitude in New World south, but not in global extent and New World north. Main conclusions The latitudinal gradients in β-deviation are primarily explained by latitudinal differences in SADs. Additionally, the expected β-diversity is determined solely by SAD. Therefore, we conclude that latitude-β-diversity gradients at local spatial scales appear to be explained by latitudinal differences in SADs.

Sex differences in stress responses may be a key factor that determines population structure. Sex ratios of Pomacea canaliculata populations usually average 1:1 at birth, but are often female-biased for adults. Low temperatures and drought are the main abiotic stresses affecting reproductive dispersal and population development. Therefore, we investigated whether Pomacea sp. (mainly P. canaliculata but might include P. maculata) exhibited sex differences in cold hardiness and desiccation tolerance. Results show that more females survived than males during cold-drought stress and overwintering. Following cold-drought stress, 58% of females and 40% of males survived at 3°C drought conditions for 6 days. With the development of cold-drought hardiness, increased amounts of bound water, glycerol and lipids were found in Pomacea sp. along with decreased free water levels. These physiological parameters exhibited sex differences in the snails, except for lipids, and the changes all showed tendencies favoring the survival of females under cold-drought stress. These results suggest that female Pomacea sp. may be more viable than males under cold and dry conditions. Fil: Guo, Jing. South China Agricultural University. College of Natural Resources and Environment, Department of Ecology; República de China Fil: Xu, Wubing. South China Agricultural University. College of Natural Resources and Environment, Department of Ecology; República de China Fil: Martín, Pablo Rafael. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Laboratorio de Ecología; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Bahía Blanca. Instituto de Ciencias Biológicas y Biomédicas del Sur. Universidad Nacional del Sur. Departamento de Biología, Bioquímica y Farmacia. Instituto de Ciencias Biológicas y Biomédicas del Sur; Argentina Fil: Zhang, Chunxia. South China Agricultural University. College of Natural Resources and Environment, Department of Ecology; República de China Fil: Zhang, Jiaen. South China Agricultural University. College of Natural Resources and Environment, Department of Ecology; República de China. Guangdong Engineering Research Center for Modern Eco-agriculture and Circular Agriculture; China. Ministry of Agriculture, Key Laboratory of Agro-Environment in the Tropics; China

Though coarse root biomass is an important part in biomass of forest ecosystems, few studies were found in subtropical area. In this study, whole digging method was used to determine the biomass of coarse root (diameter>2 mm) of 175 trees of 8 species in subtropical evergreen forests. The 8 species includes Castanopsis fargesii , Castanopis sclerophylla , Schima superba , Pinus massoniana , Cunninghamia lanceolata , Liquidambar formosana , Sassafras tzumu , Alniphyllum fortunei . Also, the lost roots during excavation were corrected by developing scaling relationship between biomass of root and diameter. Then, four kinds of allometric models for each species and combined trees were fitted to link stem diameter at breast height (dbh) and height ( H ) to coarse root biomass. The results showed that all the scaling relationship between biomass of root and diameter of roots were significant ( P P R 2 values than the height-coarse root biomass. The results also indicate that dbh is an adequate estimator for coarse root biomass of subtropical evergreen trees. The results in this study provide important information to estimate the coarse root biomass in subtropical evergreen forests.

The distribution and etching rate of flow pattern defects (FPDs) in germanium- doped Czochralski (GCZ) silicon (Si) wafers with light and heavy dopants—either boron (B) or phosphorus (P)—have been investigated. In the lightly doped (both B and P) Czochralski (CZ) Si crystals, the FPD densities in GCZ Si decrease with the increase of Ge concentration. In the heavily B-doped GCZ Si crystals, the FPDs are denser compared with the heavily B-doped CZ Si, whereas the reverse is true in the heavily P-doped GCZ Si and CZ Si crystals. It is also shown that the etching rates in the lightly doped CZ Si crystals can be slightly enlarged by the Ge doping. It is proposed that, in lightly doped GCZ Si, Ge doping could consume free vacancies and thus form high-density but small-sized voids, while the stress compensation induced by B and Ge atoms could increase the vacancy concentration in heavily B-doped GCZ Si, leading to sparse and large-sized voids.

A dislocation-free silicon single crystal doped with 1020 cm-3 germanium (Ge) has been grown using the Czochralski (CZ) growth technique. The Ge concentration in the seed-end and tang-end of the crystal was 8×1019cm-3and 1.6×1020 cm-3, respectively. The effective segregation coefficient of Ge, the distribution of flow pattern defects (FPDs) and the wafer warpage have been characterized. Both the effective segregation coefficient and the equilibrium segregation coefficient of Ge in silicon were evaluated. Then, the density of FPDs was traced from seed-end to tang-end of the ingot, a suppression of FPDs by Ge doping was shown. That is probably because the Ge atoms consume free vacancies and thus a higher density of smaller voids is formed. Furthermore, the mechanical strength of wafers has also been characterized by batch warpage analysis. The warpage in the seed-end was larger than that in the tang-end of the ingot, showing that the mechanical strength of wafers is enhanced by Ge doping. Such improvement is interpreted by an enhanced dislocation pinning effect associated with the enhanced nucleation of grown-in oxygen precipitates in the Ge-doped silicon wafers. (© 2011 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

During the last decade the 300 mm Si wafer has been optimized and one is already studying 450 mm crystals and wafers. The in­creasing silicon crystal diameter shows two important trends with respect to substrate characteristics: the interstitial oxygen concen­tration is decreasing while the size of grown in voids (COP's) in vacancy-rich crystals is increasing. The first effect is due the suppression of melt movements by the use of magnetic fields leading to a more limited transport of oxy­gen to the crystal. This and the decreasing thermal budget of ad­vanced device processing leads to reduced internal gettering capa­city. The increasing COP size is due to the combination of decreas­ing pulling rate and thermal gradient leading to a decreased void nucleation and increased thermal budget for void growth. The ef­fect of Ge doping in the range between 1E16 cm^-3 and 1E19 cm^-3 on both COP's and oxygen precipitation will be discussed.