木本植物茎叶功能性状及其关系随环境变化的研究进展

植物功能性状反映了植物对生长环境的响应和适应,是植物与环境相互作用的结果。植物功能性状之间的关系决定了植物的生活史对策,进而影响多物种的共存和生物多样性的维持。本文综述了叶大小、比叶面积、叶寿命和木质密度、叶大小-小枝大小、叶内生物量分配和叶大小-数量等随环境变化的研究进展,并简述其变化机理。植物功能性状及其关系的研究已经取得了很多成果,建立起了一套有效的研究方法和理论体系;但在今后的研究中,还需要对植物的地上部分和地下部分植物性状之间的协变关系、当年生末端小枝上功能性状间的关系的普遍性,以及叶大小-数量的等速关系在整个被子植物中的保守程度等几个方面进行深入研究。我国常绿阔叶林物种的植物功能性状及其关系研究较少,有待加强和系统化。     

环境与植物中硒形态研究进展

本文综述了近年来在环境及植物中的硒形态研究方面的进展。在土壤和水中各种不同形态硒的分布情况与pH值及其它特性之间的关系;植物中各种有机硒化合物的含量,可能的结构和硫素之间的关系,植物对硒的吸收转化过程等等。     

环境与植物中硒形态研究进展

本文综述了近年来在环境及植物中的硒形态研究方面的进展。在土壤和水中各种不同形态硒的分布情况与ｐＨ值及其它特性之间的关系;植物中各种有机硒化合物的含量,可能的结构和硫素之间的关系,植物对硒的吸收转化过程等等     

现代生物化学与分子生物学研究技术在植物微生物生态学中的应用

植物微生物生态学是研究植物微生态系统的一门学科,以植物组织细胞内微生物的组成、功能、演替,以及微生物之间和微生物与宿主之间的相互作用关系为研究对象。现代生物化学与分子生物学技术在植物微生物生态学研究领域的作用日益明显。介绍了上述技术及其在植物微生物生态学研究领域的应用进展,并对其在该领域的利用和发展进行了展望。     

VA菌根在植物生态学研究中的意义

植物生态学是研究植物和环境之间相互作用关系规律的科学。土壤、地形、气候、各种生物都是重要的环境因素 ,它们影响着植物群落的区系组成、结构、空间分布、物种多样性以及生态系统的稳定性、生产力等 ,因而在生态学研究中受到了充分的重视[2 0 ] 。然而植物与土壤微生物之间的关系 ,尤其是植物与ＶＡ菌根菌形成的共生体 ,即ＶＡ菌根在植物生态学研究中则很少有人注意。近 30年来的发现和研究证实 ,ＶＡ菌根菌与植物形成的ＶＡ菌根共生关系也是植物生态学研究中不可忽视的一种重要关系 ,这是因为 :①在自然生态系统中 ,80 %的维管束植物具…     

植物病原-媒介昆虫互作:研究进展与展望

大多数植物病毒及一些植物病原细菌由介体昆虫传播。植物病原与介体昆虫关系的研究有助于找到防控介体传播病原的关键环节,因此植物病原与介体昆虫的互作关系是植物病原传播机理研究中的核心问题。本文概述了国内外在植物病原与介体昆虫互作研究的最新进展,推介了本专辑论文的主要内容,并在此基础上,从生态和进化的角度提出了在植物病原-媒介昆虫互作研究中以下3个值得关注的研究方向:(1)植物病原与介体昆虫互作对生态系统的影响;(2)昆虫介体传播植物病毒的不同方式之间的关联性以及病毒、介体和植物之间的协同进化关系;(3)自然条件下植物病原-媒介昆虫互作的机理。植物病原与媒介昆虫互作的研究,既是生态和进化的理论问题,也和植物病原及其介体昆虫的绿色防控密切相关。     

兰科植物菌根真菌研究新见解

兰科(Orchidaceae)在地球生命系统演化中占有十分重要的地位,几乎全部兰科植物均处于不同程度的濒危状态,研究兰科菌根真菌对于保护珍稀濒危兰科植物具有重要意义。该文在对菌根真菌相关的概念及研究方法进行综述的基础上,对兰科菌根真菌的主要类群、特异性及其与兰科植物稀有性之间的关系,以及兰科菌根真菌与兰科植物之间的营养关系和进化关系进行了总结。兰科菌根真菌的研究方法可以归纳为经典研究方法、早期分子生物学方法、rDNA片段高通量测序法、宏基因组学方法。兰科菌根真菌类群主要隶属于担子菌门(Basidiomycota)、子囊菌门(Ascomycota)和毛霉门(Mucoromycota)。根据兰科菌根真菌特异性与否,首次明确了兰科菌根真菌定植关系可分为三大类:特异性定植、广泛性定植和特异-广泛兼性定植。根据营养关系特点,首次将兰科植物与菌根真菌之间的营养关系划分为三大类:兰花单向利好型、典型共生型、分工合作型。兰科菌根真菌特异性与兰科植物稀有性之间的关系呈现出两面性,而兰科菌根真菌与兰科植物之间是否存在协同进化关系还需要更多的研究才能阐明。此外,该文还对兰科菌根真菌领域今后的研究提出了一些思路。     

Can the scaling of plant nitrogen to phosphorus be altered by global change? An empirical test

全球变化可能引起土壤中各种养分的供应失衡,进而导致陆地植物中氮(N)和磷(P)元素化学计量学的不平衡。前人的研究报道了全球变化因子对植物N、P含量和N:P的影响,但鲜有研究探讨全球变化因子是否影响以及如何影响这两种元素之间的异速关系。本研究利用改变降水(增雨和干旱)、增温和N添加处理的野外控制试验,结合异速函数 N = βP^α (或对数转换后的线性关系：Log N = Log β + α Log P),检验了中国西北地区黄土高原半干旱草原植物N和P化学计量特征及N和P之间的异速关系对这些全球变化因子的响应。研究结果表明,干旱和增温均降低了植物P浓度,N添加增加了植物N浓度,这些都导致植物N:P增加。干旱、增温和N添加没有显著改变植物N和P浓度之间异速关系的斜率(即N和P浓度对数转换后的线性关系斜率α),但是显著增加了其截距(Log β)。这些结果表明,全球变化因子可能不会影响植物N和P之间的协同变化关系,植物中N和P之间可能存在着紧密的耦合关系。这些结果将有助于我们更好地理解全球变化背景下的植物养分动态和元素平衡。     

植物功能性状、功能多样性与生态系统功能:进展与展望

植物功能性状与生态系统功能是生态学研究的一个重要领域和热点问题。开展植物功能性状与生态系统功能的研究不仅有助于人类更好地应对全球变化情景下生物多样性丧失的生态学后果,而且能为生态恢复实践提供理论基础。近二十年来,该领域的研究迅速发展,并取得了一系列的重要研究成果,增强了人们对植物功能性状-生态系统功能关系的认识和理解。本文首先明确了植物功能性状的概念,评述了近年来植物功能性状–生态系统功能关系领域的重要研究结果,尤其是植物功能性状多样性–生态系统功能关系研究现状;提出了未来植物功能性状与生态系统功能关系研究中应加强植物地上和地下性状之间关系及其与生态系统功能、植物功能性状与生态系统多功能性、不同时空尺度上植物功能性状与生态系统功能,以及全球变化和消费者的影响等方面。     

用现代分子生物学方法揭示植物与昆虫的相互关系

昆虫与植物之间相互关系的研究由来已久。1 964年Ｅｈｒｌｉｃｈ和Ｒａｖｅｎ提出了协同进化 (ｃｏｅｖｏ ｌｕｔｉｏｎ) [1 ] 的概念后 ,更大大促进了植物与昆虫相互关系的研究。马世骏高度重视这一领域的研究 ,指出协同进化的观点是研究生物进化的方法论的基础之一[2 ] 。钦俊德对昆虫与植物的关系作了系统的论述和总结[3] 。以往研究昆虫与植物之间的相互关系 ,主要依靠分析昆虫的习性与相关植物的外部形态和内含次生物质之间的关系 ,辅以数学手段及计算机工具来进行 ,虽然取得了大量卓有成效的成果 ,但都还未能直接从绝大多数生物的遗传…     

植物邻体干扰的研究范畴、热点及意义

系统介绍了确定邻体和度量邻体竞争指数的常用方法,以及邻体干扰研究的热点问题和研究意义。植物邻体干扰研究热点主要包括：(1)邻体干扰对植物个体存活率的影响;(2)邻体干扰对生物多样性的影响;(3)构件水平上的邻体干扰效应;(4)基株对邻体干扰的适应;(5)邻体干扰对植物个体生长速率的影响。     

Response of gas exchange to neighborhood interference in leaves of teak (Tectona grandis L. f.) in a tropical plantation forest

The growth performance of individual plants in a population can be affected by the plant-plant interaction, which has been well recognized and is called neighborhood interference. Though mechanisms are still unclear, the variations in gas exchange parameters in relation to the neighborhood interference between individual plants are crucial for evaluating the effects of plant-plant interaction. CO₂ assimilation in leaves of teak under natural conditions of dry seasons and wet seasons as well as its response to variations in light flux density and CO₂ concentration in different neighborhood interferences were simultaneously measured with Li-6400 portable photosynthesis system in a 21-year-old tropical plantation forest in Jianfengling, Hainan Island, China. This article dealt with the change rule of neighborhood interference on tree characteristics of gas exchange and its dynamic response to light en-vironments of individual plants. Diurnal courses of photosynthesis of individual leaves were not affected by neighborhood interfer-ence, but net photosynthetic rates showed a negative relationship with the intensity of neighborhood interference. The ratio of daily average P_n in weak, moderate, strong and heavy neighborhood interferences was 2.5:2.3:1.7:1.0, and the daily maximum P_n in weak interference was 2.8 times that in heavy interference. Leaf transpiration and stomatal conductance decreased with the increasing of interference intensity. Characteristics of photosynthetic light response and CO₂ response changed with the neighborhood interference, and values of leaf gas exchange parameters including A_sat, Q_sat, α_A, CE, V_cmax and J_max in weak interference were enhanced by 2.7, 1.3, 1.4, 2.7, 1.9 and 2.8 times, respectively, than those in heavy interference. But changes in those parameters partly depended on light environment and CO₂ concentration, and the influence of changes in light environment on weak interference individuals was sig-nificantly stronger than that on heavy interference. Beyond the growth CO₂ concentration, the influence resulting from changes in CO₂ concentration on heavy interference individuals was obviously stronger than that on weak interference. Neighborhood interference can be described as a major means of intraspecific competition of population in a plantation forest with uniform forest structure and consistent management. Carbon assimilation can be affected by the neighborhood interference, and result in divergence in growth performance. Indices of neighborhood interference can be used to evaluate the intraspecific competition, and based on this point, we can make maximum use of resources after stand structure has been well adjusted.     

Encroachment of woody plants and its impact on pastoral livestock production in the Borana lowlands, southern Oromia, Ethiopia

Encroachment of woody plants has been among the major threats to the livelihoods of Borana pastoralists and their ecosystem. An approach that integrated vegetation survey and pastoralists’ perception was followed to study the impacts of encroachment of woody plants in the Borana lowlands, Ethiopia. Density of woody species was determined in 192 plots of 500 m². Canopy cover of woody plants was estimated in 123 quadrates of 400 m². Pastoralists’ perception was assessed through group discussions and a semi‐structured questionnaire. Results showed that plant density was 3014 woody plants ha^?1. Cover of woody plants was 52%, indicating an increasing trend from ≤40% cover reported in the early 1990s. It was concluded that the increase of woody plants density and cover has crossed the critical threshold and has entered into the encroached condition. Principal components analysis (PCA) and redundancy analysis (RDA) also showed that woody plants were negatively correlated with herbaceous biomass. Commiphora africana, Acacia melliphera, A. drepanolobium, A. brevispica and Lannea rivae were among the dominant encroachers. RDA revealed that soil nutrients were positively correlated with woody plants density and cover. The pastoralists perceived that encroachment of woody plants had decreased the production of their grazingland. A ban on fire was perceived as the major factor that caused encroachment of woody plants. Re‐utilization of fire and strengthening of traditional rangeland management strategies are recommended.     

IMPORTANCE OF TIME OF GERMINATION AND SOIL DEPTH ON GROWTH OF PROSOPIS GLANDULOSA (LEGUMINOSAE) SEEDLINGS IN THE PRESENCE OF A C4 GRASS

In an investigation of the causes of the invasion of woody plants into grasslands, competition between seedlings of Prosopis glandulosa Torr. and Bouteloua curtipendula (Michx.) Torr. was examined. Introduction of P. glandulosa into a B. curtipendula neighborhood significantly reduced P. glandulosa dry mass when compared to P. glandulosa growth alone. The greater the time interval from P. glandulosa germination to addition of B. curtipendula, the less interference the grass had on woody plant growth. Reciprocally, the greater the time interval from B. curtipendula germination to addition of P. glandulosa, the more interference the grass had on woody plant growth. Prosopis glandulosa belowground dry mass was <0.02 g (all in the upper 30 cm of soil) when planted after B. curtipendula at any soil depth, but if planted alone its root dry mass ranged from 2 to 8 g depending on depth. Prosopis glandulosa seedling dry mass increased linearly with soil depth, while B. curtipendula dry mass reached a plateau. In general, belowground dry mass of P. glandulosa was distributed throughout the soil depth examined (decreasing with depth), while 80% of B. curtipendula dry mass was found in the upper 30 cm of soil, suggesting a partitioning of soil resources. Data suggest that P. glandulosa and perhaps other shade-intolerant woody species that establish in grasslands do so in disturbances or vegetation gaps. Gaps may close, but by this time woody plant roots are below grass roots, thus partitioning soil resources and reducing interspecific competition.     

光皮桦群落邻体干扰指数的研究

影响植物个体生长的因素很多 ,这其中不仅有其自身的遗传特性在起作用 ,而且与其所处的生境立地质量以及它对环境资源的利用状况也有着密切地内在联系。生境在影响植物生长的同时 ,植物的生命活动及生长过程也在不断地影响和改变着环境条件 ,使其朝着有利于或不利于邻体生长的方向发展。生物与环境之间这种相互作用、相互影响 ,就是生态学领域里的邻体干扰。本文通过对福建卫闽光皮桦 (Ｂｅｔｕｌａｌｕｍｉｎｉｆｅｒａ)群落邻体干扰指数的研究 ,分析了邻体干扰指数与光皮桦生长速度间的相互联系 ,揭示了光皮桦个体大小与邻体干扰指数和生…     

浙江仙居俞坑森林群落物种多样性研究

分别采用物种丰富度、物种多样性指数和群落均匀度指标对浙江省仙居县俞坑森林群落的物种多样性进行测定和分析。结果表明：本木植物的物种多样性以生境优越的常绿阔叶林为高,木本植物的物种丰富度、物种多样性指数明显大于草本植物。在群落垂直结构中,木本植物等2层的物种丰富度、物种多样性指数均显著大于第1层。物种丰富度以木本第3层最大,草本层最小;而物种多样性指数、群落均匀度则以木本第2层最大、草本层最小。木本植物各层次、草本层的物种多样性各项指标在群落各样地间均有一定的差异。     

Self‐thinning and Tree Competition in Savannas

This paper examines the feasibility of applying self‐thinning concepts to savannas and how competition with herbaceous vegetation may modify self‐thinning patterns among woody plants in these ecosystems. Competition among woody plants has seldom been invoked as a major explanation for the persistence of herbaceous vegetation in mixed tree–grass ecosystems. On the contrary, the primary resource‐based explanations for tree–grass coexistence are based on tree–grass competition (niche‐separation) that assumes that trees are inferior competitors unless deeper rooting depths provide them exclusive access to water. Alternative nonresource‐based hypotheses postulate that trees are the better competitors, but that tree populations are suppressed by mortality related to fire, herbivores, and other disturbances. If self‐thinning of woody plants can be detected in savannas, stronger evidence for resource‐limitation and competitive interactions among woody plants would suggest that the primary models of savannas need to be adjusted. We present data from savanna sites in South Africa to suggest that self‐thinning among woody plants can be detected in low‐disturbance situations, while also showing signs that juvenile trees, more so than adults, are suppressed when growing with herbaceous vegetation in these ecosystems. This finding we suggest is evidence for size‐asymmetric competition in savannas.     

舟山群岛獐的食性研究

利用野外观察、粪便显微组织学分析和投喂实验等方法对舟山群岛獐的食性进行了研究。结果表明,研究地的獐所食植物共有137种,隶属于61科115属,其中豆科植物在取食种类和取食频次上均多于其它科植物。尽管獐对植物科和种的选择在四季间没有显差别,但取食科和种的数量依然从春天到冬天呈递减趋势,并且冬天与其它3个季节差别较大。獐的食物中,每个季节都含有非禾草类草本植物、禾草类草本植物、木本植物和蕨类植物,且其食物组成在季节间亦无显差异;除木本植物外,獐对其它3类植物的选择在季节间有显差异。獐在冬天较多选择木本植物,而其它季节较多选择草本植物,但木本植物和非禾草类草本植物在四季食物组成中均占较高比例,而禾草类植物所占的比例很小。因此,笔认为舟山群岛的獐应该偏向于嫩食。     

Is vascular plant species diversity a predictor of bryophyte species diversity in Mediterranean forests?

This study aimed to (i) investigate the congruence among the species composition and diversity of bryophytes and vascular plants in forests; (ii) test if site prioritization for conservation aims by the maximization of the pooled number of vascular plant species is effective to maximize the pooled number of bryophyte species. The study was performed in six forests in Tuscany, Italy. Four-hundred and twenty vascular plant species (61 of which were woody) and 128 bryophyte species were recorded in 109 plots. Despite the good predictive value of the compositional patterns of both woody plants and total vascular with respect to the compositional pattern of bryophytes, the species richness of the latter was only marginally related to the species richness of the former two. Bryophyte rare species were not spatially related to rare plant species and neither coincided with the sites of highest plant species richness. The species accumulation curves of bryophytes behaved differently with respect to those of woody plants or total vascular plants. Reserve selection analysis based on the maximization of the pooled species richness of either woody plants or total vascular plants were not effective in maximizing the pooled species richness of bryophytes. This study indicates that species diversity of vascular plants is not likely to be a good indicator of the bryophyte species diversity in Mediterranean forests.     

Leaf nitrogen and phosphorus concentration and the empirical regulations in dominant woody plants of shrublands across southern China

Aims Understanding the changes in N and P concentration in plant organs along the environmental gradients can provide meaningful information to reveal the underline mechanisms for the geochemical cycles and adaptation strategies of plants to the changing environment. In this paper, we aimed to answer: (1) How did the N and P concentration in leaves of evergreen and deciduous woody plants change along the environmental gradients? (2) What were the main factors regulating the N and P concentration in leaves of woody plants in the shrublands across southern China?
Methods Using a stratified random sampling method, we sampled 193 dominant woody plants in 462 sites of 12 provinces in southern China. Leaf samples of dominant woody plants, including 91 evergreen and 102 deciduous shrubs, and soil samples at each site were collected. N and P concentration of the leaves and soils were measured after lapping and sieving. Kruskal-Wallis and Nemenyi tests were applied to quantify the difference among the organs and life-forms. For each life-form, the binary linear regression was used to estimate the relationships between leaf log [N] and log [P] concentration and mean annual air temperature (MAT), mean annual precipitation (MAP) and log soil total [N], [P]. The effects of climate, soil and plant life-form on leaf chemical traits were modeled through the general linear models (GLMs) and F-tests.
Important findings 1) The geometric means of leaf N and P concentrations of the dominant woody plants were 16.57 mg·g^-1 and 1.02 mg·g^-1, respectively. The N and P concentration in leaves (17.91 mg·g^-1, 1.14 mg·g^-1) of deciduous woody plants was higher than those of evergreen woody plants (15.19 mg·g^-1, 0.89 mg·g^-1). The dependent of leaf P concentration on environmental (climate and soil) appeared more variable than N concentration. 2) Leaf N and P in evergreen woody plants decreased with MAT and but increased with MAP, whereas those in deciduous woody plants showed opposite trends. With increase in MAP, leaf P concentration decreased for both evergreen and deciduous woody plants. 3) Soil N concentration had no significant effect on both evergreen and deciduous woody plants. However, leaf P concentration of the tow increased significantly with soil P concentration. (4) GLMs showed that plant growth form explained 7.6% and 14.4% of variation in leaf N and P, respectively. MAP and soil P concentration contributed 0.8% and 16.4% of the variation in leaf P, respectively. These results suggested that leaf N was mainly influenced by plant growth form, while leaf P concentration was driven by soil, plant life-form, and climate at our study sites.