植物群落邻体间的系统发育关系是否影响邻体效应?

植物群落邻体间的系统发育关系是密度制约的重要预测因子,但在不同研究结论中邻体间系统发育关系对邻体效应的影响不一致。该文基于Web of Science、Google Scholar和CNKI三个数据库,通过关键词检索邻体间系统发育关系对邻体效应的影响的相关文献(1980.01.01~2022.05.01),对标题、摘要和全文进行筛选,纳入分析文献35篇。邻体间系统发育关系对邻体效应的影响有三种:系统发育负密度制约效应(PNDD)、系统发育正密度制约效应(PPDD)和无系统发育密度制约,其文献篇数依次递减。PNDD主要受资源竞争、天敌和病原体的影响;PPDD与共生真菌、生境异质性小和生境过滤相关;而植物早期邻体间无直接的相互作用和性状无系统发育信号会导致无系统发育密度制约。邻体间系统发育密度制约结论不一致主要是因为不同研究地点的环境异质性、研究方法、尺度和研究对象的不同。因此,在探究邻体间系统发育对邻体效应的影响时,应尽可能考虑这些因素的影响。

10份续断属植物亲缘关系的ISSR分析（英文）

续断属（Dipsacus L．）植物是中国续断科（Dipsacaceae）传统中药材，但属下种间亲缘关系仍存在不准确性鉴定。本研究拟采用10条多态性较高的ISSR（Inter-simple sequence repeat）标记从分子水平研究10份续断属植物的分类和种间亲缘关系，为该属植物的科学分类提供资料。从100条ISSR引物中筛选出多态性较高的10条，对10份续断材料进行PCR扩增，共扩增出947条DNA带，其中多态性条带828条，平均多态性条带百分率为87．4％，表明续断属植物具有丰富的遗传变异。遗传相似系数变化范围在0．557～0．806，平均为0．661。聚类分析结果表明，10份续断在相似系数水平0．582处可分为2个大类，进一步在0．702又可分为5个小类群。第1大类群包括3个小类群，第1小类群包括4分大理续断[DL（L），DL（W），DL（H），DL（WS）]，第2小类群包括日本续断（RB）和恩施续断（ES），第3小类群包括2份川续断[C（J）和C（D）]，这表明小类群问品系亲缘关系比较近，基因交流比较频繁；第2大类群包括大头续断（DT）和深紫续断（SZ），两者遗传距离较远，分别构成另外两个小类群。主成份分析与聚类分析所得的结果基本一致。研究结果还发现日本续断（RB）和恩施续断（ES）两者亲缘关系较近（0．2101），且两者的地理分布有较大的重叠，可能两者基因交流比较频繁，由于环境的不同形态上稍有差异。推测恩施续断可能为日本续断的一个变种，当然这还需要进一步深入研究。

Responses of Dobera glabra and Eight Co-Occurring Species to Drought and Salinity Stress at a Savanna-Scrub Ecotone:Implications in the Face of Climate Change

To quantify the resistance of different co-occurring species to drought and osmotic stress (salinity stress), plant water (Ψ) and osmotic (Ψp) potentials were measured during the dry season. We applied a pressure chamber and cryoscopy to measure Ψ and Ψp, respectively. The species revealed a wide range of responses to water stress (-0.83 to -5.8 MPa) and osmotic stress (-1.3 to -3.2 MPa) and not all plants fit closely into one or the other category. Evergreen species tended to have lower Ψ than deciduous species. Notably, Dobera glabra, well known as drought indicator tree in the region, showed the lowest Ψ (up to -5.8 MPa) and Ψp (-3.2 MPa). This indicates its outstanding drought and osmotic stress tolerance and explains its ability to thrive in drought prone areas and years. The recent expansion of A. oerfota and A. mellifera in the study area could be related to their tolerance of osmotic stress, which may imply a trend of soil salinization. The division of plant responses into categories or strategies can be valuable aid to understanding long-term plant survival and distribution, monitor site condition and predict the direction of future changes.

Generalizing plant–water relations to landscapes

Aims Changing climate and land use patterns make it increasingly important that the hydrology of catchments and ecosystems can be reliably characterized.The aim of this paper is to identify the biophysical factors that determine the rates of water vapor loss from different types of vegetation,and to seek,from an array of currently available satelliteborne sensors,those that might be used to initialize and drive landscape-level hydrologic models.Important Findings Spatial variation in the mean heights,crowd widths,and leaf area indices(LAI)of plant communities are important structural variables that affect the hydrology of landscapes.Canopy stomatal conductance(G)imposes physiological limitation on transpiration by vegetation.The maximum value of G(Gmax)is closely linked to canopy photosynthetic capacity,which can be estimated via remote sensing of foliar chlorophyll or nitrogen contents.Gcan be modeled as a nonlinear multipliable function of:(i)leaf–air vapor pressure deficit,(ii)water potential gradient between soil and leaves,(iii)photosynthetically active radiation absorbed by the canopy,(iv)plant nutrition,(v)temperature and(vi)the CO_(2) concentration of the air.Periodic surveys with Light Detection and Ranging(LiDAR)and interferometric RADAR,along with high-resolution spectral coverage in the visible,near-infrared,and thermal infrared bands,provide,along with meteorological data gathered from weather satellites,the kind of information required to model seasonal and interannual variation in transpiration and evaporation from landscapes with diverse and dynamic vegetation.

植物生长潜力而非系统发育关系预测荒废农田土壤生物对外来和本土植物的作用

植物能够调控土壤生物群落,而后者将对后期发生的植物适合度和群落结构产生显著影响。长期种植的单一农作物能够显著调控土壤生物群落,而新近荒废农田中土壤生物如何调控外来和本土杂草定植目前还不清楚,这严重束缚了农田杂草治理能力的提升。本研究采集新近荒废的玉米地表层土壤,选取58种华中地区常见农田杂草(28种外来和30种本土植物)为对象开展实验。通过将植物种植于伽马射线灭菌或未灭菌土壤,定量评价了土壤生物对植物地上、地下和总生物量的影响,探讨了实验物种-玉米系统发育距离和土壤效应是否相关,探究了能够预测土壤效应的关键植物性状。结果发现:(i)总体而言,土壤生物显著抑制实验植物生长,表明土壤拮抗生物(如病原菌等)发挥主导作用;(ii)伴随植物生长潜力提升,土壤生物对植物的抑制作用逐渐增强,而土壤生物对实验植物的调控作用与实验物种-玉米系统发育距离无关;(iii)相对于本土植物,外来植物(尤其多年生物种)被土壤生物抑制的程度更高。这些结果表明,植物生长潜力能够有效预测土壤生物对植物生长的调控作用,而且新近荒废农田土壤生物具有抵御外来植物入侵的潜力。

四川攀西地区云南松群落物种多样性和谱系多样性对紫茎泽兰入侵的影响

外来植物入侵严重威胁着入侵地本土植物多样性和生态系统功能,认识外来物种的入侵机制有助于提高对入侵植物的防控能力。本文以攀西地区云南松(Pinus yunnanensis)林下外来入侵植物紫茎泽兰(Ageratina adenophora)为研究对象,基于大量野外群落调查,从群落可入侵性入手,分析了环境因子和群落物种多样性、谱系多样性等群落生态学特征对紫茎泽兰入侵的影响。结果表明:海拔、坡向和火烧强度等环境因子和冠层郁闭度、灌木层盖度等生物因子对研究区紫茎泽兰入侵强度没有显著影响(P>0.05);但群落灌木层物种多样性和草本层组分种与紫茎泽兰的亲缘关系显著影响紫茎泽兰的入侵强度(P<0.05),说明灌木层对光照等环境资源的占用和草本层(同层)物种对相似资源的竞争能够在很大程度上抑制紫茎泽兰的入侵。

Regulation Mechanisms of Stomatal Oscillation

Stomata function as the gates between the plant and the atmospheric environment. Stomatal movement, including stomatal opening and closing, controls CO2 absorption as the raw material for photosynthesis and water loss through transpiration. How to reduce water loss and maintain enough CO2 absorption has been an interesting research topic for some time. Simple stomatal opening may elevate CO2 absorption, but, in the meantime, promote the water loss, whereas simple closing of stomatal pores may reduce both water loss and CO2 absorption, resulting in impairment of plant photosynthesis. Both processes are not economical to the plant. As a special rhythmic stomatal movement that usually occurs at smaller stomatal apertures, stomatal oscillation can keep CO2 absorption at a sufficient level and reduce water loss at the same time, suggesting a potential improvement in water use efficiency. Stomatal oscillation is usually found after a sudden change in one environmental factor in relatively constant environments. Many environmental stimuli can induce stomatal oscillation. It appears that, at the physiological level, feedback controls are involved in stomatal oscillation. At the cellular level, possibly two different patterns exist： （i） a quicker responsive pattern; and （ii） a slower response. Both involve water potential changes and water channel regulation, but the mechanisms of regulation of the two patterns are different. Some evidence suggests that the regulation of water channels may play a vital and primary role in stomatal oscillation. The present review summarizes studies on stomatal oscillation and concludes with some discussion regarding the mechanisms of regulation of stomatal oscillation.

当前气候、古气候和生境异质性对中国常绿阔叶木本植物生物地理格局的影响（英文）

Understanding biogeographic patterns and the mechanisms underlying them has been a main issue in macroecology and biogeography, and has implications for biodiversity conservation and ecosystem sustainability. Evergreen broad-leaved woody plants(EBWPs) are important components of numerous biomes and are the main contributors to the flora south of 35°N in China. We calculated the grid cell values of species richness(SR) for a total of 6265 EBWP species in China, including its four growth-forms(i.e., tree, shrub, vine, and bamboo), and estimated their phylogenetic structure using the standardized phylogenetic diversity(SPD) and net relatedness index(NRI). Then we linked the three biogeographical patterns that were observed with each single environmental variable representing the current climate, the last glacial maximum(LGM)–present climate variability, and habitat heterogeneity, using ordinary least squares regression with a modified t-test to account for spatial autocorrelation. The partial regression method based on a general linear model was used to decompose the contributions of current and historical environmental factors to the biogeographical patterns observed. The results showed that most regions with high numbers of EBWP species and phylogenetic diversity were distributed in tropical and subtropical mountains with evergreen shrubs extending to Northeast China. Current mean annual precipitation was the best single predictor. Topographic variation and its effect on temperature variation was the best single predictor for SPD and NRI. Partial regression indicated that the current climate dominated the SR patterns of Chinese EBWPs. The effect of paleo-climate variation on SR patterns mostly overlapped with that of the current climate. In contrast, the phylogenetic structure represented by SPD and NRI was constrained by paleo-climate to much larger extents than diversity, which was reflected by the LGM–present climate variation and topog-raphy-derived habitat heterogeneity in China. Our study highlights the importance of embedding multiple dimensions of biodiversity into a temporally hierarchical framework for understanding the biogeographical patterns, and provides important baseline information for predicting shifts in plant diversity under climate change.