Population-level variation in plant secondary chemistry,and the population biology of herbivores

Summary Modern population ecology is becoming increasingly spatially-explicit. For insect hervibores, spatial variation in plant quality is a critical component of distribution and abundance. We argue that populationlevel measurements of phytochemical variation among individual plants has not kept pace with recent developments in population ecology. With examples from our own work, we demonstrate the importance of spatial variation in plant chemistry for insect herbivores, and suggest that phytochemistry should play a central role in the development of any spatially-based ecological theory.     

基于数据库的植物功能性状研究现状文献计量学分析

植物功能性状数据库是功能生态学研究的重要工具.了解基于植物功能性状数据库的植物功能性状研究现状,对探讨功能多样性和生物多样性具有重要的指导意义.介绍植物功能性状数据库的类型、影响力的评价方法和使用方法,并整理了17个植物功能性状库(附表).同时,通过Web of Science检索了2008-2018年间基于植物功能性状数据库开展植物功能性状研究的论文,从刊文数量、期刊分布、研究机构、主要作者、研究热点等方面进行分析.结果表明:基于数据库开展植物功能性状研究的文章数量和被引次数呈快速增长的趋势.当前此方向的研究主要以少数学者、机构为核心,大量论文发表在少数期刊上.研究热点主要体现在群落生态学、气候变化和性状进化、恢复和生存策略等方面.未来应加强研究者、研究机构之间的合作,数据共享,建立全球型的数据完善的植物功能性状数据库,同时加强数据标准化处理,解决地下性状和生理性状等难以获取及量化的问题,完善化石记录的植物性状和植物不同生长阶段的植物功能性状数据.(图5表4参60附表1)     

The evolution of CSR life-history strategies in a plant model with explicit physiology and architecture

This paper introduces a functional-structural plant model based on artificial life concepts and L-systems. This model takes into account realistic physiological rules, the architecture of the plants and their demography. An original benefit of this approach is that it allows the simulation of plant evolution at both functional and life-history levels implementing mutations to the L-systems and a set of genetic parameter values. The conducted experiments focus on the evolutionary emergence of different life history strategies in an environment with heterogeneous resource availability and disturbance frequency. It is found that, depending on the encountered conditions, the plants develop three major strategies classified as competitors, stress-tolerators and ruderals according to Grime's CSR theory. Most of the evolved characteristics comply with theoretical biology or field observations on natural plants. Besides these results, our modelling framework is highly flexible and many refinements can be readily implemented depending on the issues one intends to address. Moreover, the model can readily be used to address many questions at the interface between evolutionary ecology, plant functional and community ecologies and ecosystem ecology.     

From individuals to ecosystem function: toward an integration of evolutionary and ecosystem ecology

An important goal in ecology is developing general theory on how the species composition of ecosystems is related to ecosystem properties and functions. Progress on this front is limited partly because of the need to identify mechanisms controlling functions that are common to a wide range of ecosystem types. We propose that one general mechanism, rooted in the evolutionary ecology of all species, is adaptive foraging behavior in response to predation risk. To support our claim, we present two kinds of empirical evidence from plant-based and detritus-based food chains of terrestrial and aquatic ecosystems. The first kind comes from experiments that explicitly trace how adaptive foraging influences ecosystem properties and functions. The second kind comes from a synthesis of studies that individually examine complementary components of particular ecosystems that together provide an integrated perspective on the link between adaptive foraging and ecosystem function. We show that the indirect effects of predators on plant diversity, plant productivity, nutrient cycling, trophic transfer efficiencies, and energy flux caused by consumer foraging shifts in response to risk are qualitatively different from effects caused by reductions in prey density due to direct predation. We argue that a perspective of ecosystem function that considers effects of consumer behavior in response to predation risk will broaden our capacity to explain the range of outcomes and contingencies in trophic control of ecosystems. This perspective also provides an operational way to integrate evolutionary and ecosystem ecology, which is an important challenge in ecology.     

Participatory Approach for Rapid Assessment of Plant Diversity through a Folk Classification System in a Tropical Rainforest: Case Study in Xishuangbanna, China

Abstract:  Rural indigenous people are often very knowledgeable about plant and animal species, including their identification and ecology. The use of indigenous knowledge has increasingly attracted attention in scientific circles. The Dai people, a dominant nationality in southwestern Yunnan, China, have developed their own traditional plant classification system. In a case study in Xishuangbanna, we compared the differences in number of plant species identified between scientific and Dai folk classification. The Dai people identified more than 80% of the plant species, and the correspondence between folk and scientific plant species was 87.7%. Our results indicate that folk plant classification could be used in rapid assessment of plant species in certain regions. The use of folk systems of plant classification for rapid biodiversity assessment will contribute to conservation of both indigenous knowledge and regional biodiversity.     

Microbes do not follow the elevational diversity patterns of plants and animals

The elevational gradient in plant and animal diversity is one of the most widely documented patterns in ecology and, although no consensus explanation exists, many hypotheses have been proposed over the past century to explain these patterns. Historically, research on elevational diversity gradients has focused almost exclusively on plant and animal taxa. As a result, we do not know whether microbes exhibit elevational gradients in diversity that parallel those observed for macroscopic taxa. This represents a key knowledge gap in ecology, especially given the ubiquity, abundance, and functional importance of microbes. Here we show that, across a montane elevational gradient in eastern Peru, bacteria living in three distinct habitats (organic soil, mineral soil, and leaf surfaces) exhibit no significant elevational gradient in diversity (r2<0.17, P>0.1 in all cases), in direct contrast to the significant diversity changes observed for plant and animal taxa across the same montane gradient (r2>0.75, P<0.001 in all cases). This finding suggests that the biogeographical patterns exhibited by bacteria are fundamentally different from those of plants and animals, highlighting the need for the development of more inclusive concepts and theories in biogeography to explain these disparities.     

植物根圈污染生态研究进展

阐述了植物根圈的概念 ,根圈三大结构主成份是 (1)植物根系 ,(2 )微生物 ,(3)土壤或水等 ,并从它们的相互关系出发讨论了国内外有关根圈污染生态的研究情况 ,同时提出了根圈污染生态的研究前景和意义。     

Knowledge gain and behavioral change in citizen-science programs

Citizen-science programs are often touted as useful for advancing conservation literacy, scientific knowledge, and increasing scientific-reasoning skills among the public. Guidelines for collaboration among scientists and the public are lacking and the extent to which these citizen-science initiatives change behavior is relatively unstudied. Over two years, we studied 82 participants in a three-day program that included education about non-native invasive plants and collection of data on the occurrence of those plants. Volunteers were given background knowledge about invasive plant ecology and trained on a specific protocol for collecting invasive plant data. They then collected data and later gathered as a group to analyze data and discuss responsible environmental behavior with respect to invasive plants. We tested whether participants without experience in plant identification and with little knowledge of invasive plants increased their knowledge of invasive species ecology, participation increased knowledge of scientific methods, and participation affected behavior. Knowledge of invasive plants increased on average 24%, but participation was insufficient to increase understanding of how scientific research is conducted. Participants reported increased ability to recognize invasive plants and increased awareness of effects of invasive plants on the environment, but this translated into little change in behavior regarding invasive plants. Potential conflicts between scientific goals, educational goals, and the motivation of participants must be considered during program design.     

Modelling plant species richness using functional groups

Conservation biologists increasingly rely on spatial predictive models of biodiversity to support decision-making. Therefore, highly accurate and ecologically meaningful models are required at relatively broad spatial scales. While statistical techniques have been optimized to improve model accuracy, less focus has been given to the question: How does the autecology of a single species affect model quality? We compare a direct modelling approach versus a cumulative modelling approach for predicting plant species richness, where the latter gives more weight to the ecology of functional species groups. In the direct modelling approach, species richness is predicted by a single model calibrated for all species. In the cumulative modelling approach, the species were partitioned into functional groups, with each group calibrated separately and species richness of each group was cumulated to predict total species richness. We hypothesized that model accuracy depends on the ecology of individual species and that the cumulative modelling approach would predict species richness more accurately. The predictors explained plant species richness by ca. 25%. However, depending on the functional group the deviance explained varied from 3 to 67%. While both modelling approaches performed equally well, the models of the different functional groups highly varied in their quality and their spatial richness pattern. This variability helps to improve our understanding on how plant functional groups respond to ecological gradients.     

高速公路中央分隔带景观设计——以焦新高速公路为例

中央分隔带是高速公路中对视觉景观影响最重要的一部分,在对其具体的生念、环境、景观和安全要求进行分析的基础上,提出景观设计的方法。根据笔者在焦新高速公路种植设计中的体验,从植物配置、生态要求等方面对中央分隔带的绿化景观设计进行了总结。     

土壤种子库研究的几个热点问题

土壤种子库是指存在于土壤表层凋落物和土壤中全部活性种子的总和。土壤中有活性的种子是植物群落的一部分,是新植株的来源。土壤种子库可以分为瞬时土壤种子库和持久土壤种子库。随着群落生态学的发展,土壤种子库的研究已经成为植物生态学重要的一部分,研究内容主要包括:(1)土壤种子库的组成和分布;(2)土壤种子库的动态;(3)地上植被与土壤种子库的关系;(4)干扰对土壤种子库的作用;(5)土壤种子库在生态恢复中的作用。文章在对目前土壤种子库的研究方法、主要研究内容方面总结的基础上,认为土壤种子库在合适的干扰作用下对退化生态系统的恢复以及植被更新发挥重要的作用,同时需进一步加强对这一过程中种子萌发、幼苗建立限制因素的研究。     

Random forests for classification in ecology

Classification procedures are some of the most widely used statistical methods in ecology. Random forests (RF) is a new and powerful statistical classifier that is well established in other disciplines but is relatively unknown in ecology. Advantages of RF compared to other statistical classifiers include (1) very high classification accuracy; (2) a novel method of determining variable importance; (3) ability to model complex interactions among predictor variables; (4) flexibility to perform several types of statistical data analysis, including regression, classification, survival analysis, and unsupervised learning; and (5) an algorithm for imputing missing values. We compared the accuracies of RF and four other commonly used statistical classifiers using data on invasive plant species presence in Lava Beds National Monument, California, USA, rare lichen species presence in the Pacific Northwest, USA, and nest sites for cavity nesting birds in the Uinta Mountains, Utah, USA. We observed high classification accuracy in all applications as measured by cross-validation and, in the case of the lichen data, by independent test data, when comparing RF to other common classification methods. We also observed that the variables that RF identified as most important for classifying invasive plant species coincided with expectations based on the literature.     

Insect herbivores, density dependence, and the performance of the perennial herb Solanum carolinense

How insect herbivores affect plant performance is of central importance to basic and applied ecology. A full understanding of herbivore effects on plant performance requires understanding interactions (if any) of herbivore effects with plant density and size because these interactions will be critical for determining how herbivores influence plant population size. However, few studies have considered these interactions, particularly over a wide enough range of densities to detect nonlinear effects. Here we ask whether plant density and herbivores influence plant performance linearly or nonlinearly, how plant density affects herbivore damage, and how herbivores alter density dependence in transitions between plant size classes. In a large field experiment, we manipulated the density of the herbaceous perennial plant Solanum carolinense and herbivore presence in a fully crossed design. We measured plant size, sexual reproduction, and damage to plants in two consecutive years, and asexual reproduction of new stems in the second year, allowing us to characterize both plant performance and rates of transition between plant size classes across years. We found nonlinear effects of plant density on damage. Damage by herbivores and plant density both influenced sexual and asexual reproduction of S. carolinense; these effects were mostly mediated via effects on plant size. Importantly, we found that herbivores altered the pattern of linear density dependence in some transition rates (including survival and asexual reproduction) between plant size classes. These results suggest that understanding the ecological or evolutionary effects of herbivores on plant populations requires consideration of plant density and plant size, because feedbacks between density, herbivores, and plant size may complicate longer-term dynamics.     

丛枝菌根对盐胁迫的响应及其与宿主植物的互作

丛枝菌根真菌(Arbuscular Mycorrhizae Fungi,AMF)作为陆地生态系统的组成部分之一,在促进宿主植物对土壤养分和水分的吸收、提高植物生物量生产、调节种群和群落的结构、维持生态系统的稳定性等方面发挥了重要作用。其中,盐渍化是自然生态系统中广泛存在的一种胁迫生境条件,全球盐渍化土地约占耕地总面积的10%,因而探讨AM菌根在此胁迫生境下对宿主植物生长的影响具有重要意义。从以下几个方面,围绕盐胁迫条件、AM菌根和宿主植物三者之间的关系对当前国际上相关领域的研究进展进行了综述:1)AM真菌对盐胁迫的响应,包括菌根共生体形成、菌根侵染率、AM真菌的分布、菌丝体生长发育、孢子的形成和分布等;2)盐胁迫条件下AM菌根对宿主植物的效应,包括AM菌根促进宿主植物对P、N等元素的吸收、降低植物体内Na 的含量、提高光合作用能力,进而提高植物的生物量和对植物的群落结构产生影响等;3)AM菌根提高宿主植物耐盐性的机理,分别从植物根系形态的改变、水分吸收能力的加强、细胞内营养物质的平衡,以及细胞生理代谢的调节等方面对AM菌根促进植物抗盐性的机理进行了剖析。     

中国北方典型污染城市主要绿化树种的滞尘效应(英文)

为研究城市人工植被的滞尘效应及其对城市生态环境的改善作用,以中国北方典型污染城市--临汾市为例.通过野外典型采样法和室内分析,测定了不同生活型主要绿化植物的滞尘能力,讨论了植物的滞尘量与滞尘时间的关系,并且研究了污染程度及距污染源距离对植物滞尘能力的影响.结果表明,在同一降尘条件下,不同生活型植物滞尘能力差异表现为草本植物的滞尘能力显著高于其它生活型植物(落叶乔木,灌木和藤本植物),而其它生活型植物间的滞尘能力无显著差异性;对针叶林来说,圆柏和雪松的滞尘能力间亦存在显著差异.在不同的污染情况下(污染程度及和污染源的距离不同),同种植物的滞尘能力亦有明显的差异,这与植物的高度和生长特性有关.而且,随时间推移,植物叶片的滞尘量呈现周期变化.而不是一个随时间无限增长的量,也有其饱和量.因此,在进行城市绿化设计时,需要综合考虑绿化树种的滞尘能力、滞尘周期及其生长环境情况等.     

洞庭湖区的湖垸农业与可持续发展对策

在调查分析洞庭湖区围湖垦殖和湖垸农业形成的历史的基础上，归纳了湖垸农业面临的生态环境问题：洪涝灾害发生频率加大；水面减少，生物多样性降低；环境污染严重，湿地生态功能衰退；土壤退化和潜育化严重；血吸虫病死灰复燃。并结合已有的经验，提出了湖垸农业可持续发展的对策措施：认真实施生态保护工程，减少泥沙淤积；调整湖垸农业结构，建立有利于避灾、减灾新模式；退田还湖，发展替代农业，发展莲藕、籽藕、茭白等水生经济植物种植；与企业结合，发展油菜、马铃薯、亚麻等工业原料作物；利用欧美杨耐涝性强的特点，在地势较高的季节性淹没的洲滩地，发展以林为主的林农复合经营模式，湖洲草地发展草食畜禽替代模式。     

锡林河河漫滩湿地植物群落特征及物种多样性分析

内蒙古高原草原区湿地具有不同于典型湿地的特征,同时还兼具草原的一些特征,在保持生物多样性和珍惜物种资源方面具有不可替代的重要作用.通过样方调查,以重要值为数量特征,采用指示种分析法和多样性指数测定,对内蒙古高原典型内陆河流——锡林河中游河漫滩湿地植被群落特征及物种多样性进行了系统分析和研究.结果表明:(1)锡林河中游河漫滩湿地植被依微地形由高河漫滩向低河漫滩可分为芦苇+羊草,黄花苜蓿+无茫雀麦,灰脉苔草+早熟禾,水甜茅群落,小糠草+蒙古扁穗草等5个群落,以禾本科、菊科、豆科三大草本为主,建群种有别于典型湿地和典型草原群落.(2)植物水分生态类型以湿生、中生为主且无水生类型,具有典型湿地和草原的双重特征;(3)湿地植物群落物种多样性、均匀性和丰富度表现出相似的变化趋势,多样性和丰富度较草甸草原低但高于典型草原;(4)锡林河河漫滩湿地植物群落是典型河流湿地和典型草原之间的过渡类型.表6,参28.     

Mycorrhizal fungal identity and diversity relaxes plant-plant competition

There is a great interest in ecology in understanding the role of soil microbial diversity for plant productivity and coexistence. Recent research has shown increases in species richness of mutualistic soil fungi, the arbuscular mycorrhizal fungi (AMF), to be related to increases in aboveground productivity of plant communities. However, the impact of AMF richness on plant-plant interactions has not been determined. Moreover, it is unknown whether species-rich AMF communities can act as insurance to maintain productivity in a fluctuating environment (e.g., upon changing soil conditions). We tested the impact of four different AMF taxa and of AMF diversity (no AMF, single AMF taxa, and all four together) on competitive interactions between the legume Trifolium pratense and the grass Lolium multiflorum grown under two different soil conditions of low and high sand content. We hypothesized that more diverse mutualistic interactions (e.g., when four AMF taxa are present) can ease competitive effects between plants, increase plant growth, and maintain plant productivity across different soil environments. We used quantitative PCR to verify that AMF taxa inoculated at the beginning of the experiment were still present at the end. The presence of AMF reduced the competitive inequality between the two plant species by reducing the growth suppression of the legume by the grass. High AMF richness enhanced the combined biomass production of the two plant species and the yield of the legume, particularly in the more productive soil with low sand content. In the less productive (high sand content) soil, the single most effective AMF had an equally beneficial effect on plant productivity as the mixture of four AMF. Since contributions of single AMF to plant productivity varied between both soils, higher AMF richness would be required to maintain plant productivity in heterogeneous environments. Overall this work shows that AMF diversity promotes plant productivity and that AMF diversity can act as insurance to sustain plant productivity under changing environmental conditions.     

Effects of More Frequent and Prolonged El Niño Events on Life-History Parameters of the Degu, a Long-Lived and Slow-Reproducing Rodent

Abstract:  Global climate change (GCC) can have profound effects on species whose ecology is governed primarily by climatic factors. The ecology of small mammals inhabiting semiarid Chile is strongly affected by the El Niño Southern Oscillation (ENSO). During La Niña events in this area, dry conditions prevail and species may disappear from the thorn-scrub habitat. Conversely, El Niño events bring high rainfall, and associated pulses of food trigger small-mammal population increases. We used capture–mark–recapture to study responses of the degu ( Octodon degus ), a dominant small mammal, to variation in rainfall over 18 years. In response to a recent trend toward wetter conditions, degus reached record-high densities and maintained more stable numbers in the area. Underlying mechanisms involved variation in adult survival, juvenile persistence, and fecundity linked to rainfall changes during consecutive years (i.e., rainfall phases). During prolonged droughts, degus had low survival and produced fewer offspring, with low persistence. Following high rainfall, these parameters reversed; consecutive wet years resulted in further increases. Weak declines in fecundity and adult survival and high persistence of juveniles explained delayed responses to deteriorating conditions in initial dry years. If GCC leads to increased frequency of El Niño events, we anticipate greater numerical dominance of degus in semiarid Chile and possible range expansion. Furthermore, degus have strong impacts on other small mammal and some plant species, are important prey species, and are agricultural pests and disease reservoirs. Hence, GCC has the potential to dramatically influence their ecology in northern Chile and to have cascading effects on other components of this system.