Abstract Climate and land-cover changes are major threats to biodiversity, and their impacts are expected to intensify in the future. Protected areas (PAs) are crucial for biodiversity conservation. However, their effectiveness under future climate and land-cover changes remains to be evaluated. Moreover, the impacts of climate and land-cover changes on multi-dimensions of biodiversity are rarely considered when expanding PAs. Using distributions of 8,732 woody species in China and species distribution models, we identified species that will be threatened by future climate and land-cover changes (i.e. species with significant projected loss of suitable habitats by the 2070s) under different dispersal scenarios. We then estimated the geographical patterns in species richness (SR) and phylogenetic diversity (PD) of threatened species, evaluated the effectiveness (i.e. the changes in SR and PD) of Chinese PAs and identified conservation priorities for future PA expansion. Approximately 12%–38% of woody species will be threatened under different scenarios. These species tend to be clustered in the tree of life, and their SR and PD show consistent spatial patterns, being highest at low latitudes. PAs currently protect 90% of threatened species. However, their SR and PD of threatened species within PAs will decrease by 30%–40% by the 2070s, which reduces the PA effectiveness, especially for PAs at low elevations and those with low topographic heterogeneity and high natural vegetation loss. The conservation priorities identified from the SR and PD of the threatened species are mainly in mountains in southern China, the Yunnan-Guizhou Plateau and Taiwan Island. PA expansion and ecological corridors in these regions are needed to conserve threatened species. Synthesis and applications. We present a systematic study of the impacts of future climate and land-cover changes on the conservation status of woody species and PA effectiveness in China. Our results suggest that future climate and land-cover changes will reduce PA effectiveness, and the spatial prioritization of biodiversity conservation should consider the influences of future global changes on biodiversity. These results shed new light on the conservation priorities for the post-2020 expansion of PAs in China.

<p id="C2"><strong>Aims:</strong> The genome size between species, especially in angiosperms, can be extremely diverse. Here, we compiled genome size data for 11,215 angiosperm species from 2,226 genera and 245 families to explore the relationships between four functional traits (i.e. seed mass, maximum plant height, leaf nitrogen and phosphorus concentrations) with genome size in angiosperms from different life forms (i.e. annual herbs, perennial herbs, and woody plants).<br><strong>Method:</strong> We used the 1C-value of DNA content as a measurement for genome size. Genome sizes were obtained from the latest version of Kew Plant DNA C-values Database and Genome Size in Asteraceae Database (GSAD). We also complemented our taxon sampling with data from the literature over the past 10 years. We obtained life form and functional trait from <i>Flora of China</i>, <i>Flora of North America</i> and the Seed Information Database (SID). We used the most recent updated time-calibrated phylogeny published by Smith and Brown in 2018, and pruned it to the 6,612 species from our species list. We used two indices (i.e. Blomberg’s <i>K </i>and Pagel’s <i>λ</i>) to test for the prescence of a phylogenetic signal for the evolution of angiosperm genome size. We performed a standardized major axes (SMA) Model II and focused on the relationships between genome size and the four functional traits. We also conducted a principal components analysis (PCA) to explore trade-offs between functional traits and genome size in angiosperms with different life forms.<br><strong>Results:</strong> The genome size for most angiosperms was small and few species had large genomes. The median value of angiosperm genome size was 1.58 pg with perennial herbs having the largest median genome size (2.5 pg), followed by annual herbs (1.55 pg), and then woody species (1.14 pg). Variation of the genome size was greatest in perennial herbs distributed over a wider range than woody species and then annual herbs. Tests for phylogenetic signals with genome size indicated that evolution was non-random. The value for Blomberg’s <i>K</i> was 0.031 (<i>P</i>&lt; 0.001) and the value for Pagel’s <i>λ</i> was 0.943 (<i>P</i>&lt; 0.001. There was also a significant difference between functional traits and genome size among the three different life forms. Our results from the standardized major axes regression found that there was a significant relationship between seed mass with genome size in herbs but not woody plants. However, the relationship of maximum plant height was significant with genome size in woody plants but not herbs. There were no significant correlations between leaf nitrogen or phosphorus concentration with genome size except for leaf nitrogen concentration in woody plants. When looking at the relationship between four functional traits with genome size, we fund a negative correlation between seed mass and maximum plant height with genome size, and saw no significant correlation with leaf nitrogen or phosphorus concentration which is consistent with the SMA results.<br><strong>Conclusion:</strong> Our study highlights that the correlation between functional traits and genome size vary between herbaceous and woody species and suggests that trade-offs between genome size, life forms and functional traits might play an essential role in ecological adaptation and evolution of angiosperms.</p>

Protected areas (PAs) play a pivotal role in maintaining viable populations of species and minimizing their habitat loss. Globally, there are currently over 200,000 PAs that cover approximately 15% of land area. The post-2020 global biodiversity framework aims to expand this coverage to 30% by 2030. However, focusing only on the percentage coverage of PAs without evaluating their effectiveness may fail to achieve conservation goals. Here, we use a multidimensional approach incorporating species, climate and anthropogenic vulnerabilities to assess the threat levels in over 2500 PAs in China. We identify nearly 10% of PAs as the most threatened PAs in China and about one-fifth PAs as hotspots of climate and anthropogenic vulnerabilities. We also find high climate instability in species vulnerability hotspots, suggesting an elevated likelihood of species' extirpation therein. Our framework could be useful in assessing resiliency of global protected lands and also in selecting near optimal areas for their future expansion.

Although contemporary climate has been identified as one of the major determinants of large-scale species diversity patterns, its effect on species diversity greatly varies among clades. Understanding the drivers of the variation in species diversity–climate relationships (DCRs) across clades, which is critical for developing general mechanisms underlying the effects of climate on species diversity patterns, remains a current challenge. Using newly compiled distribution data of 914 Rosaceae species in China and a dated genus-level phylogeny, we first assessed the DCRs for the entire family, the two major growth forms (woody versus herbaceous), and each genus separately, and then explored the drivers underlying the variation in DCRs across different clades. We found that the DCRs significantly differed between woody and herbaceous plants and among different genera in this family. Closely related genera had more similar species diversity patterns and DCRs than expected. Both the ancestral climate niches of different genera and the discrepancy between contemporary and ancestral climate niches explained the variations in DCR slopes across genera with high explanatory power, indicating the effect of niche conservatism on DCRs. Our study suggests that niche conservatism is a major driver of DCR variations between clades, which enhances our understanding of the mechanisms underlying large-scale species diversity patterns.

Abstract Angiosperm sexual systems are fundamental to the evolution and distribution of plant diversity, yet spatiotemporal patterns in angiosperm sexual systems and their drivers remain poorly known. Using data on sexual systems and distributions of 68453 angiosperm species, we present the first global maps of sexual system frequencies and evaluate sexual system evolution during the Cenozoic. Frequencies of dioecy and monoecy increase with latitude, while hermaphrodites are more frequent in warm and arid regions. Transitions to dioecy from other states were higher than to hermaphroditism, but transitions away from dioecy increased since the Cenozoic, suggesting that dioecy is not an evolutionary end point. Transitions between hermaphroditism and dioecy increased, while transitions to monoecy decreased with paleo-temperature when paleo-temperature >℃. Our study demonstrates the biogeography of angiosperm sexual systems from a macroecological perspective, and enhances our understanding of plant diversity patterns and their response to climate change.

China is one of the diversity centers of gymnosperms. Nearly one-fifth (195 species) of gymnosperms are located in China, but 69 species are threatened. To date, the conservation status of gymnosperms, especially threatened gymnosperms in China, remains largely unknown, which seriously restricts the comprehensive protection of gymnosperms. Understanding the distribution pattern of species richness and exploring the relationships between species richness and environmental factors are key steps for their protection. In this study, we first constructed a database for the 69 threatened species of gymnosperms with 13 270 distribution records. It is found that 31 of the grid cells (50 × 50 km) cover all threatened gymnosperm species in China, and the grid cells of threatened gymnosperms are mainly distributed in the southern area of the Yellow River, with a distribution center in the Western Sichuan Plateau. Then, we evaluated the conservation status of threatened gymnosperms, and the results indicate that 9 (13%) threatened gymnosperms are distributed outside of nature reserves. Therefore, there are still conservation gaps in the protection of threatened gymnosperms in China. We should give more attention to unprotected threatened gymnosperms and conduct taxonomic studies on the species without detailed distribution records. Finally, conservation priority areas and priority conservation levels of threatened gymnosperms in China were proposed. The Western Sichuan Plateau is the most important conservation priority area of threatened gymnosperms. This study will shed light on plant protection and forest management in China.

The tea family (Theaceae) has a highly unusual amphi-Pacific disjunct distribution: most extant species in the family are restricted to subtropical evergreen broadleaf forests in East Asia, while a handful of species occur exclusively in the subtropical and tropical Americas. Here, we used an approach that integrates the rich fossil evidence of this group with phylogenies in biogeographic analysis to study the processes behind this distribution pattern. We first combined genome-skimming sequencing with existing molecular data to build a robust species-level phylogeny for c.130 Theaceae species, resolving most important unclarified relationships. We then developed an empirical Bayesian method to incorporate distribution evidence from fossil specimens into historical biogeographic analyses and used this method to account for the spatiotemporal history of Theaceae fossils. We compared our method with an alternative Bayesian approach and show that it provides consistent results while significantly reduces computational demands which allows analyses of much larger data sets. Our analyses revealed a circumboreal distribution of the family from the early Cenozoic to the Miocene and inferred repeated expansions and retractions of the modeled distribution in the Northern Hemisphere, suggesting that the current Theaceae distribution could be the remnant of a larger continuous distribution associated with the boreotropical forest that has been hypothesized to occupy most of the northern latitudes in the early Cenozoic. These results contradict with studies that only considered current species distributions and showcase the necessity of integrating fossil and molecular data in phylogeny-based parametric biogeographic models to improve the reliability of inferred biogeographical events. [Biogeography; genome skimming; phylogenomics; plastid genome; Theaceae.]

In natural forests at a demographic equilibrium state, the size frequency distribution (SFD) of trees is linked with their size-dependent growth and mortality rates. While the mean growth rate (MGR) of each size class is generally used for determining the SFD, the variance in the growth rate (VGR) has always been ignored. Here, based on the analyses with Kolmogorov forward equation, we show that in general, the VGR can flatten the slope of the SFD and, in particular, can address the contradiction between the size-dependent MGR and the −2 power-law SFD in the metabolic scaling theory. We traced the origin of the VGR to the intrinsic stochasticity in the allometric growth coefficients of trees and deduced its functional form based on variance propagation. Using the forest censuses data from Barro Colorado Island, we verified the prediction of the VGR and indicated its indispensability in the theory of forest size-structure formation.

Elevational range shifts of mountain species in response to climate change have profound impact on mountain biodiversity. However, current evidence indicates great controversies in the direction and magnitude of elevational range shifts across species and regions. Here, using historical and recent occurrence records of 83 plant species in a subtropical mountain, Mt. Gongga (Sichuan, China), we evaluated changes in species elevation centroids and limits (upper and lower) along elevational gradients, and explored the determinants of elevational changes. We found that 63.9% of the species shifted their elevation centroids upward, while 22.9% shifted downward. The changes in centroid elevations and range size were more strongly correlated with changes in lower than upper limits of species elevational ranges. The magnitude of centroid elevation shifts was larger than predicted by climate warming and precipitation changes. Our results show complex changes in species elevational distributions and range sizes in Mt. Gongga, and that climate change, species traits and climate adaptation of species all influenced their elevational movement. As Mt. Gongga is one of the global biodiversity hotspots, and contains many threatened plant species, these findings provide support to future conservation planning.

毛茛科是真双子叶植物的基部类群之一，包含多种药用植物，具有较高的保护价值，但关于毛茛科物种多样性和谱系多样性大尺度格局及其影响因子的研究还比较匮乏，特别是以较高分辨率分布数据为基础的物种多样性格局研究尚未见报道。该文旨在: 1)建立欧亚大陆东部毛茛科植物分布数据库，估算不同生活型物种多样性和谱系多样性格局, 并探究格局的形成机制。2)分析毛茛科物种多样性和谱系多样性的相关关系，确定多样性热点地区，为毛茛科保护规划提供依据。根据中国、中亚五国(哈萨克斯坦、吉尔吉斯斯坦、塔吉克斯坦、土库曼斯坦、乌兹别克斯坦)、蒙古和俄罗斯等国家的区域和地方植物志，建立了“欧亚大陆东部地区毛茛科物种分布数据库”。该数据库包含了欧亚大陆东部地区1688种毛茛科物种的分布数据，空间分辨率为100 × 100 km2。在此基础上，估算了毛茛科全部物种及不同生活型植物的物种多样性和谱系多样性格局，并利用广义线性模型和等级方差分离方法分析了毛茛科物种和谱系多样性格局与环境因子的关系。最后比较了物种多样性和谱系多样性的相关关系，确定了毛茛科的古热点地区。结果显示: 1)欧亚大陆东部毛茛科植物物种和谱系多样性均呈明显的纬度格局，且在山区具有较高的多样性。2)毛茛科植物物种和谱系多样性受现代气候、地形异质性和末次冰期以来的气候变化的共同影响，但不同影响因子的相对贡献率在物种和谱系多样性及不同生活型之间差异显著。3)中高纬度地区的谱系多样性高于给定物种数的预期，是毛茛科的古热点地区，在毛茛科保护规划中应受到重视。

Abstract Aim Invertebrate-mediated dispersal has previously been proposed to promote angiosperm diversification and distribution. However, little is known about the specific impact of invertebrate-mediated dispersal on the biogeography and current distribution of plants. We aim to infer the influence of vespicochorous (hornet) and myrmecochorous (ant) dispersal on the historical biogeography of herbaceous monocot species. Location Southeast Asia, East Asia, Australia, North America. Taxon Family Stemonaceae. Method We sampled ca. 75% of the species diversity in Stemonaceae (28 out of 37 species), covering the entire distribution range of the family, to reconstruct the biogeographic history of this family. Using phylogenetic logistic regression analyses, we then tested the relationship between dispersal modes and geographic distributions. Results Stemonaceae originated on the Asian mainland during the late Cretaceous and then dispersed to North America, the western Malay Archipelago and eastern Malay Archipelago and Australia between the late Cretaceous and Pliocene. Geographical ranges of ant- versus hornet-dispersed Stemonaceae species are significantly different, with vespicochorous species having broader distribution ranges than myrmecochorous species. Main conclusions Invertebrate-mediated dispersal in Stemonaceae may promote narrow endemism and play an important role in shaping the current distribution of species. Most lineages dispersed by ants failed to cross biogeographic barriers and exhibit limited range expansion overland. Vespicochorous lineages were able to cross oceanic barriers and occupy larger continental areas and/or occur on oceanic islands.

Plant species richness (PSR) is known to affect soil organic carbon (SOC) storage. However, due to the complex origin and composition of SOC, mechanisms driving the PSR-SOC relationship are not yet fully revealed, hampering an accurate prediction of SOC dynamics under changing plant diversity. Here we investigate the effect of PSR on SOC accumulation along a natural PSR and stand age gradient in a subtropical forest with plot, litter and soil properties being considered. Biomarkers and soil fractionation are used to delineate plant and microbial components of SOC and their influences on the PSR-SOC relationship in the topsoil (0–10 cm) versus subsoil (30–40 cm). We show that PSR does positively affect SOC concentrations at both depths even after considering the effects of substrate, edaphic properties and stand age. However, the PSR-SOC relationship is driven by different pathways in the topsoil versus subsoil. In the topsoil, PSR exerts a strong additive effect on SOC accumulation after the positive influence of substrate, edaphic properties and stand age, mainly regulated by plant-derived components (represented by lignin phenols, light fraction and particulate organic matter), followed by microbial residues. By contrast, PSR has a positive effect on the accrual of microbial-derived components (represented by amino sugars and mineral-associated organic matter) but not plant residues likely via affecting dissolved organic matter (DOM) and nitrogen availability in the subsoil (i.e., DOM-microbial pathway). As a result, microbial-derived components dominate SOC variations in the subsoil, while plant-derived components play a more important role in the topsoil. These findings provide novel information on the mechanistic links between PSR and SOC accumulation at different depths and highlight the role of PSR on long-term carbon sink potentials of soils, which may aid in predicting soil carbon dynamics with plant diversity changes in Earth's system model.

<p id="C2"><strong>Aims:</strong> Ranunculaceae, one of the basal clades in eudicots of angiosperms, has a variety of medicinal plants and is of high conservation value. However, large-scale patterns in species richness and phylogenetic diversity of Ranunculaceae based on high-resolution distribution data and their environmental determinants remain poorly understood. We aims to: (1) establish a Ranunculaceae distribution database in eastern Eurasia, estimate the species diversity and phylogenetic diversity pattern of different life forms, and explore the formation mechanism of the pattern; (2) analysis the relationship between species diversity and phylogenetic diversity of Ranunculaceae, and determine the diversity hot spots to provide basis for Ranunculaceae conservation planning.<br><strong>Methods:</strong> Here, we established the first species distribution database for 1,688 Ranunculaceae species across eastern Eurasia by compiling distribution data from regional and local floral records from across China, Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, Uzbekistan, Mongolia, and Russia at a spatial resolution of 100 km × 100 km. Using this database, we mapped large-scale patterns in species richness and phylogenetic diversity for species with different life forms and explored the mechanisms underlying these patterns. We also quantified the relationship between species richness and phylogenetic diversity and identified hotspots of Ranunculaceae phylogenetic diversity.<br><strong>Results:</strong> We found a latitudinal gradient in both species richness and phylogenetic diversity and revealed that Ranunculaceae in eastern Eurasia have particularly high levels of species and phylogenetic diversity in mountainous areas. Contemporary climate, habitat heterogeneity, and climate changes since the Last Glacial Maximum (LGM) all influenced spatial patterns in species richness and phylogenetic diversity, but their relative contributions varied across life forms. Phylogenetic diversity at mid and high latitudes was higher than expected when controlling for species richness, which suggests that these latitudes may represent a paleo-biodiversity hotspot of Ranunculaceae.<br><strong>Conclusion:</strong> Consequently, these regions should be considered a key conservation priority for this important family.</p>

<p id="p00015">Leaf is one of the important organs of plants that facilitates the exchange of water and air with the surrounding environment. The morphological variation of leaves directly affect the physiological and biochemical processes of plants, which also reflects the adaptive strategies of plants to obtain resources. By focusing on several leaf morphological traits, including leaf size, leaf shape, leaf margin (with or without teeth) and leaf type (i.e. single vs. compound leaf), here, we reviewed the relevant research progresses in this field. We summarized the ecological functions of leaf morphological traits, identified their geographical distribution patterns, and explored the underlying environmental drivers, potential ecological interactions, and their effects on ecosystem functioning. We found that the current studies exploring the distribution and determinants of leaf size and leaf margin states mainly focused on single or specific taxon in local regions. Studies have also explored the genetic mechanisms of leaf morphology development. Leaf traits trade off with other functional traits, and their spatial variation is driven by both temperature and water availability. Leaf morphological traits, especially leaf size, influence water and nutrient cycling, reflect the response of communities to climate change, and can be scaled up to predict ecosystem primary productivity. Further studies should pay attention to combine new approaches to obtain unbiased data with high coverage, to explore the long-term adaptive evolution of leaf morphology, and to generalize the scaling in leaf morphology and its effect on ecosystem functioning. Leaf provides an important perspective to understand how plants respond and adapt to environmental changes. Studying leaf morphological traits provides insight into species fitness, community dynamics and ecosystem functioning, and also improves our understanding of the research progresses made in related fields, including plant community ecology and functional biogeography.</p>

<p id="p00005">Comprehensively understanding the mechanisms underlying the formation of ecosystem services is a prerequisite for maintaining the sustainable supply of ecosystem services. Plant functional traits directly participate in a variety of ecosystem processes, which in turn affect the supply of ecosystem services. Revealing the relationship between plant functional traits and ecosystem services is an important way to understand the formation mechanism of ecosystem services. Based on a systematic literature review, 86 papers on plant functional properties and ecosystem services were retrieved in the Web of Science database, and data for 466 pairs of plant functional traits and ecosystem services and 83 plant functional traits were collected. The current status of research on the relationship between plant functional traits and ecosystem services was revealed. Moreover, the main plant functional traits that affect different ecosystem services and their mechanisms underlying their impacts were also demonstrated. The results show that the research on the relationship between plant functional traits and ecosystem services mostly focuses on natural ecosystems such as grasslands and forests. Most of these studies focus on ecosystem products providing and supporting services, including biomass, net primary productivity, and soil fertility. Based on the impacts of plant functional traits on different ecosystem services, the plant functional traits can be clustered into five categories: soil-conservation-related traits, water-cycle-related traits, ecosystem- multifunction- related traits, product-providing-related traits, and pollination-biocontrol-related traits. The impacts of climate change, human activities, and variations in spatial and temporal scales on the relationship between plant functional traits and ecosystem services need to be further explored.</p>

Predicting spatial patterns in thermal tolerance and vulnerability of species under climate warming remains a challenge. Current knowledge is mainly from experiment-based thermal physiology of limited numbers of ectotherms, yet large-scale evaluations on plants remain elusive. Here, using distribution maps with spatial resolutions of 20 × 20 km for 5628 woody species in China, we propose a novel approach, i.e. thermal distribution curves, to describe species' realized thermal niches and then estimate their thermal tolerance and warming risks under projected climate warming in 2050s and 2070s. We find that species' vulnerability and potential local extinction risks within grid cells decrease with latitude and increase with aridity due to narrow thermal tolerance of species located at low latitudes and arid regions. Over 90% of species could still tolerate future warming in most areas, indicating relatively optimistic expectation of potential local extinctions. Our study presents a new framework to quantify climate warming impacts on a large number of species without sufficient physiological information and provides fundamental references for conservation planning under climate change.