Characterization and Phylogenetic Implications of the Complete Mitogenomes of Two Species in the Genus Zhangixalus(Anura:Rhacophoridae)

Mitochondrial genomes(mitogenomes)in frogs are essential for reconstructing the phylogenetic relationships and shedding light on the molecular evolution in these animals.However,there are only seven complete Rhacophoridae genomes that have been reported to date.In this paper,two complete mitogenomes of the Chinese whipping frog(Zhangixalus chenfui)and Emei tree frog(Z.omeimontis)were described,each of which was 20520 and 19782 bp in size,and had A+T contents of 64.26%and 63.83%.The two mitogenomes each included two non-coding control region(D-loop,CR),two ribosomal RNA genes(rRNAs),13 protein-coding genes(PCGs),and 22 transfer RNA genes(tRNAs),and it was found that the mitogenome of Z.chenfui also includes three tandem tRNAMet gene sequences.A typical clover-leaf structure was found for all tRNAs except for tRNASer1(AGN),which showed a reduced DHU arm.The putative D-loop region contains multiple types of tandem repeats regions.Both of these two mitogenomes showed similar pattern of gene rearrangement(tRNA-Ser-ND6-tRNA-Glu-CytbCR1-ND5-CR2-tRNA-Thr-tRNA-Leu-tRNA-Pro).Additionally,three consecutive tRNAMet genes were found for the first time in Z.chenfui,a species in the Rhacophoridae family.For all phylogenetic analyses,which were based on 13 protein-coding genes from 91 Ranoidea mitogenomes,the same phylogenetic trees were observed using either maximum likelihood or Bayesian approaches.These results suggest that the phylogenetic hypotheses for the Ranoidea(including Rhacophoridae,Mantellidae,Ranidae and Dicroglossidae)derived from these mitogenomic data could provide substantiation for the relationships of(Dicroglossidae(Ranidae,(Mantellidae,Rhacophoridae))),and support the presence of a monophyletic group in four families.Moreover,Z.omeimontis and Z.dennysi were found to cluster on the same branch,indicating that they were more closely related as a group.This group may in turn form sister groups with Z.arboreus and Z.schlegelii.However,Z.chenfui is located on the base of other species in the genera.Increased mitogenome sampling should be conducted to provide a more satisfactory resolution to the phylogeny of the Rhacophorus,Rhacophoridae,and Mantellidae.

Ecological species groups and interspecific association of vegetation in natural recovery process at Xiejiadian landslide after 2008 Wenchuan earthquake

Wenchuan earthquake on 12 May 2008 triggered numerous landslides, which disturbed vast areas of vegetation in northwest Sichuan. However, based on our primary field investigation at Xiejiadian landslide in July 2009, we found an obvious increase of the number of plant species and then we made a hypothesis that, after earthquake, vegetation at this landslide might recover by itself. In this paper, we conduct a newly field investigation at Xiejiadian landslide during November 2014 to verify this hypothesis. We investigated plant species composition at total 56 sites(trees 4, shrubs 16 and herbs 36, respectively), and calculated the Schluter's variance ratio, important values, x2 test, associationcoefficient, Ochiai index, Pearson's and Spearman's correlation coefficients, and Ecological species groups. Species sharply increased to 84 species belonging to 66 genera and 54 families, forming a complete life form containing trees, shrubs, herbs, and ground layers while only herbs detected in 2009. Moreover, an overall positive and moderately related interspecies association was detected for most of species pairs. Of total 84 species, twenty five were identified as dominant species and could be divided into four positive ecological species groups. This study verified our proposed hypothesis of self-recovery of vegetation in landslide triggered by the earthquake, and found Alnus cremastogyne, Rhus chinensis, Litsea cubeba, Vitis piasezkii and Anemone vitifolia would play a constructive role during the continuing succession of vegetation at Xiejiadian landslide.

First record of disk-footed bat Eudiscopus denticulus(Chiroptera,Vespertilionidae)from China and resolution of phylogenetic position of the genus

DEAR EDITOR,The disk-footed bat Eudiscopus denticulus(Osgood,1932)is a rare species in Southeast Asia.During two chiropteran surveys in the summer of 1981 and 2019,eight and three small Myotis-like bats with distinct disk-like hindfeet were collected from Yunnan Province,China,respectively.External,craniodental,and phylogenetic evidence confirmed these specimens as E.denticulus,representing a new genus in China.The complete mitochondrial genome consistently showed robust support for E.denticulus as a basal lineage within Myotinae.The coding patterns and characteristics of its mitochondrial genome were similar to that of other published genomes from Myotis.The echolocation signals of the newly collected individuals were analyzed.The potential distribution range of Eudiscopus in Southeast Asia inferred using the MaxEnt model indicated its potential occurrence along the southern border region of Yunnan,China.

Variation and Sexual Dimorphism of Body Size in the Plateau Brown Frog along an Altitudinal Gradient

Variation in body size and sexual size dimorphism（SSD） can have important consequences for animal ecology, behavior, population dynamics and the evolution of life-history traits. Organisms are expected to be larger in colder climate（i.e., Bergmann＇s rule） and SSD varies with body size（i.e., Rensch＇s rule）. However, the underlying mechanisms are still elusive. The plateau brown frog（Rana kukunoris）, a medium-sized anuran species with femalebiased SSD, is endemic to the Qinghai-Tibetan Plateau（QTP）. From 1797 m（Maoxiang＇ping） to 3453 m（Heihe＇qiao） in the eastern margin of the QTP, we surveyed 10 populations of R. kukunoris and collected phalanges and snout vent length（SVL） data for 258 adult individuals（199 males versus 59 females）. Based on these data, we explored how body size and SSD varying along the altitudinal gradient and examined the corresponding effects of temperature. We found body size to be larger at higher altitude for males but not for females, with likely effects from the temperature on the variation in male body size. Sex differences in growth rates may be the main cause of the variation in SSD. Our results suggested that only males follow the Bergmann＇s rule and variation in SSD of R. kukunoris do not support the Rensch＇s rule and its inverse. Therefore, the variations of body size can be different between sexes and the applicability of both Bergmann＇s rule and Rensch＇s rule should depend on species and environment where they live.

No Male Preference for Large Females in the Asian Common Toad(Duttaphrynus melanostictus):Effect of the Sex Ratio and Breeding System

Mating preferences are common in natural populations of animals.Numerous studies have shown that male mate choice can occur in a wide range of taxa.However,male mating preferences are still poorly understood in anurans.Sexual selection theory predicts that male mate choice is not expected to arise if 1) adult population exhibited a highly male-biased sex ratio which will diminish male mating success;2) males provide less parental care;3) mating success of males is associated with chorus tenure in which males would maximize their fitness by mating with multiple mates.We tested these predictions in the Asian common toad Duttaphrynus melanostictus from southeastern Tibet,China.Our field experimental results indicated that,the breeding population exhibited a highly male-biased sex ratio,called males did not defend sites which contain significant resources required by females and offspring,both sexes provided no parental care after egg-laying,and the toad species was characterized with prolonged breeding season chorus attendance.In male mate choice experiment,males did not show preferences for a larger gravid female over a smaller gravid female.We suggest that male mating success in the Asian common toad is likely determined by the number but not the quality of mates.Future research should focus on how sexual selection on male acoustic signaling and how female preference exert different types of selection pressure on male call traits in this Tibet toad.

Linkages among the functional traits,insect visitation rate and seed set of Gentiana taxa on the Tibetan Plateau

Maximum plant height(H_(max)),stem tissue mass density(SD),leaf mass per area(LMA),and relative growth rate(RGR)have all been linked to flowering phenology.However,it is still unknown whether these functional traits varying with flowering phenology are related to other floral traits associated with pollinator preference and reproductive success.We investigated the relationship between vegetative and floral traits,as well as the rates of insect visitation and seed set of fiveGentiana species in eastern Tibetan meadows.Our results showed that flowering onset and flowering offset time were all found to be positively correlated with the H_(max),SD,and LMA,but negatively correlated with the RGR.Flowering onset time was positively correlated with corolla diameter and pollen grain number,whereas was negatively correlated with flower number and flower longevity.The rates of insect visitation were positively related to flowering onset time,pollen grain number,corolla diameter,and seed set,but negatively related to flower number and longevity.Early flowering species have higher RGR but lower SD,LMA andH_(max),as well as smaller flowers,fewer pollen grains,longer flower longevity,and lower insect visitation rates than late-flowering plant species.Our findings indicate that floral traits are related to vegetative traits in Gentiana species.Also these plant trait relationships were associated with pollinator preference,and plant reproductive success of eastern Tibetan meadows.We speculate that these traits relationships are likely adaptive in unpredictable and often pollinator-limited environments in the Tibet alpine meadows.

Effects of experimental warming on soil microbial communities in two contrasting subalpine forest ecosystems,eastern Tibetan Plateau,China

Soil microbial communities are primarily regulated by environmental temperature. Our study investigated the effects of global warming on soil microbial community composition as measured via phospholipid fatty acid(PLFA) analysis and soil chemical characteristics in relation to soil depth in a dragon spruce plantation and a spruce-fir-dominated natural forestin the Eastern Tibetan Plateau. Opentop chambers were utilized to increase the soil and air temperature. Soil samples were collected from the 0-10 cm, 10-20 cm, and 20-30 cm layers after a 4-year warming. Our results showed that the soil microbial community and the contents of TC(Total carbon), TN(Total nitrogen), NO_3^-, and NH_4^+ responded differently to warming in the two contrasting forests, especially at the 0-10 cm soil depth. Warming increased soil microbial biomass at the 0-20 cm depth of soil in natural forest but reduced it at the 0-10 cm depth ofsoil in the plantation. In contrast, the TC and TN contents were reduced in most soil layers of a natural forest but increased in all of the soil layers of the plantation under warming conditions. This result suggested that the effects of warming on soil microbial community and soil C and N pools would differ according to soil depth and forest types; thus, the two contrasting forests would under go differing changes following the future climate warming in this region.

Effect of six years of nitrogen additions on soil chemistry in a subtropical Pleioblastus amarus forest, Southwest China

Soil chemistry influences plant health and carbon storage in forest ecosystems. Increasing nitrogen(N) deposition has potential effect on soil chemistry. We studied N deposition effects on soil chemistry in subtropical Pleioblastus amarus bamboo forest ecosystems. An experiment with four N treatment levels(0, 50, 150,and300 kg N ha-1a-1,applied monthly, expressed as CK,LN,MN, HN,respectively) in three replicates. After6 years of N additions, soil base cations, acid-forming cations, exchangeable acidity(EA), organic carbon fractions and nitrogen components were measured in all four seasons. The mean soil pH values in CK,LN,MN and HN were 4.71, 4.62, 4.71, and 4.40, respectively, with a significant difference between CK and HN. Nitrogen additions significantly increased soil exchangeable Al3+,EA, and Al/Ca,and exchangeable Al3+ in HN increased by 70%compared to CK. Soil base cations(Ca2+, Mg2+, K+, and Na+) did not respond to N additions. Nitrogen treatments significantly increased soil NO3--N but had little effect on soil total nitrogen, particulate organic nitrogen, or NH4~+-N. Nitrogen additions did not affect soil total organic carbon, extractable dissolved organic carbon,incorporated organic carbon, or particulate organic carbon.This study suggests that increasing N deposition could increase soil NO3--N, reduce soil pH, and increase mobilization of Al3+. These changes induced by N deposition can impede root grow and function, further may influence soil carbon storage and nutrient cycles in the future.

High Altitude Frogs (Rana kukonoris) Adopt a Diversified Bethedging Strategy in the Face of Environmental Unpredictability

Environmental unpredictability can influence strategies of maternal investment among eggs within a clutch. Models predict that breeding females should adopt a diversified bet-hedging strategy in unpredictable environments, but empirical field evidence from Asia is scarce. Here we tested this hypothesis by exploring spatial patterns in egg size along an altitudinal gradient in a frog species （Rana kukunoris） inhabiting the Tibetan Plateau. Within-clutch variability in egg size increased as the environment became variable （e.g., lower mean monthly temperature and mean monthly rainfall at higher altitudes）, and populations in environments with more unpredictable rainfall produced eggs that were smaller and more variable in size. We provide support for a diversified bet-hedging strategy in high-altitude environments, which experience dynamic weather patterns and therefore are of unpredictable environmental quality. This strategy may be an adaptive response to lower environmental quality and higher unpredictable environmental variance. Such a strategy should increase the likelihood of breeding success and maximize maternal lifetime fitness by producing offspring that are adapted to current environmental conditions. We speculate that in high-altitude environments prone to physical disturbance, breeding females are unable to consistently produce the optimal egg size due to physiological constraints imposed by environmental conditions （e.g., duration of the active season, food availability）. Species and populations whose breeding strategies are adapted to cope with uncertain environmental conditions by adjusting offspring size and therefore quality show a remarkable degree of ability to cope with future climatic changes.

Gap edge canopy buffering of throughfall deposition in a subalpine natural forest

Base cation loads are rarely considered in forest gap edge canopies,but they can play critical roles in capturing or buffering atmospheric deposition in forests with frequent gap disturbances,such as subalpine forests.We selected an expanded gap edge canopy and a closed canopy in a subalpine natural forest on the eastern Tibetan Plateau.The throughfall deposition and canopy exchange processes of common base cations(K^(+),Ca^(2+),Na^(+),and Mg^(2+))were continuously studied over two years.The results showed that the enrichment ratio and fluxes had lower levels of base cations in the gap-edge canopy than in the closed canopy,which indicated that base cations were concentrated more in the closed canopy than in the gap-edge canopy.Although Ca^(2+)in the gap-edge canopy showed a higher net throughfall flux,the annual net throughfall fluxes of K^(+),Na^(+) and Mg^(2+) within the gap-edge canopy were 1.83,6.75 and 2.95 times lower than those in the closed canopy,respectively.Moreover,dry deposition fluxes of base cations significantly decreased in the gap edge canopy compared to those in the closed canopy,and the decreasing tendency was more significant during the snowy season than during the rainy season.Overall,these results suggest that the amount of base cations in subalpine natural forest ecosystems may be overestimated when the throughfall deposition of ions in gap edge canopies is ignored.

Assessment of effective conservation of the Sichuan takin by giant panda reserves through functional zoning

The flagship species conservation strategy is widely practiced in nature reserves.However,few studies have quantitatively explored whether the current functional zoning adequately conserves the habitats of other species.To examine this problem,we selected the Tangjiahe,Xuebaoding,and Wanglang national nature reserves in southwest China and tested the protective efficiency of the giant panda(Ailuropoda melanoleuca)reserves on a local herbivore—Sichuan takin(Budorcas taxicolor tibetana)in functional zoning.We predicted that the habitat distribution of the Sichuan takin with Maxent and habitat suitability would be classified as very low,low,moderately,or highly suitable.We calculated the percentage of each type of habitat class across the core,buffer,and experimental zones in these reserves and introduced an economic index present value index to further assess the efficacy of the functional zoning in conserving the habitat of Sichuan takin.Our findings indicate that suitable habitat distributions of Sichuan takin are multicore and influenced by diverse variables in different nature reserves.The percentage of moderately suitable and highly suitable habitat in the core zone is 69%and 54%in Tangjiahe,76%and 75%in Wanglang,and 47%and 28%in Xuebaoding,respectively.The present value index of moderately and highly suitable habitat is 1.01 and 0.79(Tangjiahe),0.87 and 0.86(Wanglang),0.76 and 0.44(Xuebaoding),respectively.The efficiency of functional zoning on Sichuan takin seems lower than imagined in giant panda reserves,and species that have important impacts on local ecosystem need further estimation and greater focus.

Fighting the enemy: How rice survives the blast pathogen's attack

Global food security is threatened by rice blast disease caused by the filamentous fungus Magnaporthe oryzae.An understanding of rice resistance mechanisms is fundamental to developing strategies for disease control.In this review,we summarize recent advances in pathogen-associated molecular pattern-triggered immunity,effector-triggered immunity,defense regulator-mediated immunity,and effects of nutrient elements on rice blast resistance.We outline strategies used for breeding rice cultivars with improved disease resistance.We also present the major research challenges for rice blast disease resistance and propose approaches for future investigation.

SHY2 as a node in the regulation of root meristem development by auxin, brassinosteroids, and cytokinin

In multicellular organisms,the balance be-tween cell division and differentiation determines organ size,and represents a central unknown in devel-opmental biology.In Arabidopsis roots,this balance is mediated between cytokinin and auxin through a reg-ulatory circuit converging on the IAA3/SHORT HYPO-COTYL 2(SHY2)gene.Here,we show that crosstalk between brassinosteroids(BRs)and auxin occurs in the vascular transition zone to promote root meristem de-velopment.We found that BR increases root meristem size by up-regulating expression of the PINFORMED 7(PIN7)gene and down-regulating expression of the SHY2 gene.In addition,BES1 could directly bind to the pro-moter regions of both PIN7 and SHY2,indicating that PIN7 and SHY2 mediate the BR-induced growth of the root meristem by serving as direct targets of BES1.Moreover,the PIN7 overexpression and loss-of-function SHY2 mutant were sensitive to the effects of BR and could partially suppress the short-root phenotypes associated with deficient BR signaling.Interestingly,BRs could inhibit the accumulation of SHY2 protein in response to cytokinin.Taken together,these findings suggest that a complex equilibrium model exists in which regulatory interactions among BRs,auxin,and cytokinin regulate optimal root growth.

Ecological Characteristics of China's Key Ecological Function Areas

1 Introduction National Key Ecological Function Areas(NKEFA),which refer to regions undertaking water conservation,soil and water conservation,windbreak and sand-fixation,and biodiversity maintenance,are associated with national or regional ecological security and need to restrict extensive industrialization or urbanization.In 2010,the China’s State Council issued the National Major Function Zone Planning,which drew out 25NKEFA in restricted development zone according to two aspects including the ecological vulnerability and the ecological importance.

Nitrogen and phosphorus translocation of forest floor mosses as affected by a pulse of these nutrients

藓类是亚高山森林、北方针叶林和极地苔原等原始生态系统的重要组成部分。养分沉降是这些生态系统的主要养分来源。然而,对藓类如何利用大气沉降这一时间上异质性较高的养分来源的认识缺乏,限制了我们对藓类在生态系统养分循环中作用的认识,也制约了模拟和预测生态系统服务功能动态变化的有效性。本研究中,我们重点关注如下问题:(1)藓类新生部分的氮、磷含量随氮或磷沉降量的变化;(2)氮或磷养分沉降如何影响藓类的氮磷转运;(3)氮磷转运与藓类新生部分养分含量的关联性?为此,我们在位于青藏高原东部的亚高山冷杉林中开展了设置有不同氮、磷施加量水平的突发养分沉降实验。以林下优势度最高的塔藓和锦丝藓为对象,我们在施加实验处理8天和1年后,分别测定了不同年龄藓类茎段中的氮、磷含量。研究结果发现,养分处理8天后,锦丝藓和塔藓的所有茎段的氮或磷含量均随处理中氮或磷施加量的增加而增加,表明它们能够高效率地吸收施加的氮或磷。养分处理1年后,形成于养分处理后的新生茎段中的氮、磷含量以及氮磷比与处理后8天的藓类茎段中氮、磷含量以及氮磷比呈正相关关系,表明藓类将吸收的养分转运至新生部分,转运过程受源—库关系的调控。磷转运效率解释了新生茎段21%-23%的氮磷比变化,而氮转运与新生茎段氮磷比没有显著关系,结果暗示磷转运对藓类生长的重要性。上述结果表明,养分转运是藓类植物利用间断的沉降养分的关键机制,也使藓类成为生态系统中重要的养分库。

Prehibernation Energy Storage in Heilongjiang Brown Frogs(Rana amurensis) from Five Populations in North China

Energy storage is an important component in the life history of species that directly inlfuences survival and reproduction. The energetic demands of amphibian reproduction can differ between the sexes, with environmental conditions, reproductive pattern or process of the species, and depending upon the timing of breeding, and the reproductive season for a species. Surprisingly, comparative studies of pre-hibernation energy storage for anuran populations from different latitudes are relatively few in Asia, especially in China. Here we investigated the patterns of pre-hibernation energy storage of Heilongjiang brown frogsRana amurensis, based on ifve populations along a ifnely latitudinal gradient in north China （40.7–43.7°N）. We found that pre-hibernation energy storage of the frogs did not show a clear latitudinal cline, but differed strongly between the sexes, with males depositing more energy reserves into the muscle and liver, whereas females accumulate more energy in the gonads. The sexual differences in energy storage may result from differential timing of energy allocation for reproduction.

Ecophysiological responses of two poplar species to intraspecific and interspecific competition under different nitrogen levels

美洲黑杨(Populus deltoides)和欧美杨(P.euramericana)在中国是广泛应用的造林树种。目前,有关这两种树种在纯林和混栽林条件下对氮缺乏的响应研究还较少。本研究的目的是分析这两种植物在不同竞争条件及氮水平下的生长,形态及生理响应。以美洲黑杨和欧美杨为研究材料,以盆栽实验模拟不同竞争方式(美洲黑杨×美洲黑杨,种内竞争;欧美杨×欧美杨,种内竞争;美洲黑杨×欧美杨,种间竞争),研究不同竞争方式和氮水平(正常氮添加和氮缺乏)对两种植物特征的影响,分析其在竞争和氮缺乏条件下生长,形态及生理特性的变化。研究结果表明,在正常氮素水平下,与种内竞争相比,种间竞争显著降低了欧美杨的根重、根分配、根冠比、碳氮比,增加了其叶重、叶分配以及总叶面积;同时除了细根重、根冠比、比叶面积、根分配、总氮含量和碳氮比未受影响外,种间竞争也显著影响了美洲黑杨的生长和形态特征。此外,在正常氮水平下,美洲黑杨的叶绿素a含量、总叶绿素含量、类胡萝卜素含量以及碳同位素组成在种间竞争条件下都显著低于种内竞争,但是在欧美杨中未发现显著的种间和种内竞争差异。在种内竞争下,氮缺乏对美洲黑杨的影响比在种间竞争下更强;但对于欧美杨,氮缺乏的影响在两种竞争条件下差异并不显著。因此,在正常氮素水平下,美洲黑杨纯林栽培比与欧美杨混合栽培生长表现更好;但在氮素缺乏时,欧美杨在纯林和混合栽培条件下的表现比美洲黑杨更稳定。

Influence of tree species on soil microbial residue accumulation and distribution among soil aggregates in subtropical plantations of China

Background Microbial residues are significant contributors to stable soil organic carbon(SOC).Soil aggregates effectively protect microbial residues against decomposition;thus,microbial residue accumulation and distribution among soil aggregates determine long-term SOC stability.However,how tree species influence accumulation and distribution of soil microbial residues remains largely unknown,hindering the chances to develop policies for SOC management.Here,we investigated microbial residue accumulation and distribution in soil aggregates under four subtropical tree species(Cunninghamia lanceolata,Pinus massoniana,Michelia macclurei,and Schima superba)after 29 years of afforestation.Results Accumulation of microbial residues in the 0-10 cm soil layer was 13.8-26.7%higher under S.superba than that under the other tree species.A structural equation model revealed that tree species affected the accumulation of microbial residues directly by altering fungal biomass.Additionally,tree species significantly affected microbial residue distribution and contribution to SOC in the top 20 cm soil.In particular,microbial residue distribution was 17.2-33.4%lower in large macro-aggregates(LMA)but 60.1-140.7%higher in micro-aggregates(MA)under S.superba than that under the other species in the 0-10 cm soil layer,and 14.3-19.0%lower in LMA but 43-52.1%higher in MA under S.superba than that under C.lanceolata and M.macclurei in the 10-20 cm soil layer.Moreover,the contribution of microbial residues to SOC was 44.4-47.5%higher under S.superba than under the other tree species.These findings suggest a higher stability of microbial residues under S.superba than that under the other studied tree species.Conclusions Our results demonstrate that tree species influence long-term microbial persistence in forest soils by affecting accumulation and stabilization of microbial residues.

Cell wall associated immunity in plants

The plant cell wall is the first physical and defensive barrier against pathogens.The plant cell wall usually undergoes dynamic remodeling as an immune response to prevent infection by pathogens.In this review,we summarize advances on relationship between cell wall and immunity in plants.In particular,we outline current progresses regarding the regulation of the cell wall components,including cellulose,hemicellulose,pectin and lignin,on plant disease resistance.We also discuss the impacts of cell wall-derived cellodextrin,oligogalacturonic acid and xyloglucan/xylan oligosaccharides as potent elicitors or signal molecules to trigger plant immune response.We further propose future studies on dissecting the molecular regulation of cell wall on plant immunity,which have potentials in practical application of crop breeding aiming at improvement of plant disease resistance.

增温可增加窄叶鲜卑花高寒灌丛的土壤碳输入

植物通过凋落叶、根系凋落物和根系分泌物向土壤输入有机碳,显著影响土壤碳储量。然而,高寒灌丛生态系统这3种植物碳输入途径对气候变暖的响应仍不清楚。本文通过为期3年的野外增温实验,研究了青藏高原东部高寒灌丛优势种窄叶鲜卑花(Sibiraea angustata)凋落叶、根系凋落物和根系分泌物对土壤碳输入的相对贡献及其对增温的响应。研究结果表明,窄叶鲜卑花通过凋落叶、根系凋落物和根系分泌物向土壤输入有机碳的数量分别为77.45、90.58和26.94 g C m^(-2)。增温分别使凋落叶和根系凋落物有机碳输入轻微增加8.04和11.13 g C m^(-2),同时使根系分泌物有机碳输入显著增加15.40 g C m^(-2)。增温使根系分泌物有机碳输入途径相对贡献显著增加4.6%,分别使凋落叶和根系凋落物有机碳输入途径相对贡献轻微降低了2.5%和2.1%。这些结果表明,在青藏高原高寒灌丛生态系统中,气候变暖主要通过促进根系分泌物输入途径而不是凋落物输入途径来增加植物源土壤有机碳的输入。