种、种的多样性及退化生态系统功能的恢复和维持研究

物种多样性是生态系统的重要特征并维持系统的功能支行,生物种和不同种类构成的群落为人类提供诸如营养物质循环、生物生产力、营养功能等形式的重要生态服务,特种多样性与生态系统抵御逆境和干扰的能力紧密相关,多样性的提高会增加系统的稳定性,与单个种和种类的数量相比,功能群和功能多样性对生态系统功能的影响效应要大得多,且易于被用来测度稳定性和预测群落变化,本文提出并探讨了种对生态系统功能作用的几种形式,理解物种多样性与生态系统的功能关系能指导退化生态系统恢复和维持其功能的实践活动,尤其为恢复的初始阶段进行群落的“种类组装”提供生态理论基础。     

群落可侵入性及其影响因素

 可侵入性用于评价群落易遭受生物入侵的程度,受外来种死亡率、区域气候、干扰水平、生态系统抵抗入侵的能力、本地种竞争和抗干扰能力等因素的影响。当前对群落或区域间可侵入性的比较常以外来种数量或丰度为据,然而这两者仅代表了群落内单一的动态过程,不足以作为衡量群落可侵入性的广泛标准。借助一个描述外来种数量的简单模型阐明,由于影响可侵入性因素的复杂性,各地之间的可侵入性几乎不可比较。并从入侵过程、入侵种特性及本地种、本地群落对入侵的抵抗性几方面对群落可侵入性进行了阐述分析,其中着重介绍入侵生态中几个重要的概念,如可侵     

Engineering role models: do non-human species have the answers?

A shift from traditional engineering approaches to ecologically-based techniques will require changing societal values regarding ‘how and what’ is defined as engineering and design. Non-human species offer many ecological engineering examples that are often beneficial to ecosystem function and other biota. For example, organisms known as ‘ecosystem engineers’ build, modify, and destroy habitat in their quest for food and survival. Similarly, ‘keystone species’ have greater impacts on community or ecosystem function than would be predicted from their abundance. The capacity of these types of organisms to affect ecosystems is great. They exert controlling influences over ecosystems and communities by altering resource allocation, creating habitats and modifying relative competitive advantages.Species’ effects in ecosystems, although context-dependent, can be evaluated as ‘beneficial’ or ‘detrimental’. The evaluation depends on whether effects on other species or ecosystem function are more or less desirable from a given perspective. Organisms with beneficial impacts facilitate the presence of other species, employ efficient nutrient cycling, and are sometimes characterized by specific mutualisms. In contrast, many cases of detrimental engineering are found from introduced (i.e., exotic) species and are characterized by a loss of species richness, a lack of nutrient retention and the degradation of ecosystem integrity. Species’ impacts on ecosystems and community traits have been quantified in ecological studies and can be used similarly to understand, design and model human engineering structures and impacts on the landscape. Emulation of species with beneficial impacts on ecosystems can provide powerful guidance to the goals of ecological engineering. Using role model organisms that have desirable effects on species diversity and ecosystem function will be important in developing alternatives to traditional engineering practices.     

Restoration of wetland vegetation using soil seed banks: lessons from a project in Lake Kasumigaura, Japan

The restoration of degraded wetland ecosystems and the recovery of wetland biodiversity are important global issues. Generally, wetland restoration projects include activities to recover vegetation. A promising revegetation technique is one in which soil seed banks are utilized as the source of plant recolonization. Using such a technique, a pilot project to restore lakeshore vegetation was launched at Lake Kasumigaura, Japan, in 2002. In the project, lake sediments containing the seed banks were spread thinly (∼10 cm) on the surfaces of artificial lakeshores, which were constructed in front of concrete levees and had microtopographic variations. In total, 180 species, including six endangered or vulnerable species and 12 native submerged plants that had disappeared from the above-ground vegetation of the lake, were recorded in five recreated lakeshores (total area, 65,200 m²) during the first year of the restoration. The distribution of each restored species at the sites suggested the importance of microtopographic relief for recolonizing species-rich lakeshore vegetation. Furthermore, the origin of the source seed banks affected the species composition of the restored vegetation. On the other hand, the restoration sites were subject to exotic plant invasions. Here, we report lessons learned from the Lake Kasumigaura restoration project as a contribution to the establishment of ecologically sound revegetation techniques.     

云南木兰科植物物种资源及其种质库的研究

1980～1993年期间,在对云南省木兰科植物调查中,发现云南省有木兰科植物11属120余种并较集中地分布于滇东南,滇西南和滇西北地区。为了保存、发展和利用木兰科植物资源,建立了三个种质库基地,在24 hm 2面积内,共保存10属129种,初步建立起木兰科种质库网络。     

Soil seed bank in different habitats of the Eastern Desert of Egypt

The floristic composition and species diversity of the germinable soil seed bank were studied in three different habitats (desert salinized land, desert wadi, and reclaimed land) in the Eastern Desert of Egypt. Moreover, the degree of similarity between the seed bank and the above-ground vegetation was determined. The seed bank was studied in 40 stands representing the three habitats. Ten soil samples (each 25 × 20 cm and 5 cm depth) were randomly taken per stand. The seed bank was investigated by the seedling emergence method. Some 61 species belonging to 21 families and 54 genera were identified in the germinable seed bank. The recorded species include 43 annuals and 18 perennials. Ordination of stands by Detrended Correspondence Analysis (DCA) indicates that the stands of the three habitats are markedly distinguishable and show a clear pattern of segregation on the ordination planes. This indicates variations in the species composition among habitats. The results also demonstrate significant associations between the floristic composition of the seed bank and edaphic factors such as CaCO₃, electrical conductivity, organic carbon and soil texture. The reclaimed land has the highest values of species richness, Shannon-index of diversity and the density of the germinable seed bank followed by the habitats of desert wadi and desert salinized land. Motyka’s similarity index between the seed bank and the above-ground vegetation is significantly higher in reclaimed land (75.1%) compared to desert wadi (38.4%) and desert salinized land (36.5%).     

甘肃鸡类物种多样性研究

甘肃鸡类有19种,随纬度变化形成了物种多样性梯度。本文通过气候(年无霜天数、元月均温、年均温、7月均温和年降水量),海拔高差,纬度和植被类型多样性与各县鸡类多样性相关统计分析,揭示了7月均温,年均降水量,海拔高差和纬度是控制甘肃鸡类多样性的主要因素,而甘肃鸡类多样性与植被类型多样性无关。在降水量400—650mm和海拔高差1500—3500m的地带种类最多。一个地区物种的多少不仅取决于其离物种库的远近,还取决于这一地区环境空间异质性程度。     

Biotic resistance to plant invasion in grassland: Does seed predation increase with resident plant diversity?

Seed predation impacts heavily on plant populations and community composition in grasslands. In particular, generalist seed predators may contribute to biotic resistance, i.e. the ability of resident species in a community to reduce the success of non-indigenous plant invaders. However, little is known of predators’ preferences for seeds of indigenous or non-indigenous plant species or how seed predation varies across communities. We hypothesize that seed predation does not differ between indigenous and non-indigenous plant species and that seed predation is positively related to plant species diversity in the resident community. The seed removal of 36 indigenous and non-indigenous grassland species in seven extensively or intensively managed hay meadows across Switzerland covering a species-richness gradient of 18–50 plant species per unit area (c. 2 m²) was studied. In mid-summer 2011, c. 24,000 seeds were exposed to predators in Petri dishes filled with sterilized soil, and the proportions of seeds removed were determined after three days’ exposure. These proportions varied among species (9.2–62.5%) and hay meadows (17.8–48.6%). Seed removal was not related to seed size. Moreover, it did not differ between indigenous and non-indigenous species, suggesting that mainly generalist seed predators were active. However, seed predation was positively related to plant species richness across a gradient in the range of 18–38 species per unit area, representing common hay meadows in Switzerland. Our results suggest that generalist post-dispersal seed predation contributes to biotic resistance and may act as a filter to plant invasion by reducing the propagule pressure of non-local plant species.     

物种多样性指数及其分形分析

提出了一个新的群落α多样性测度方法。定义物种多样性指数DIV =2S -∑Si =1(1/Ni) a,式中S为群落物种数 ,Ni 为种i的个体数 ,a为对个体数敏感程度的控制参数。物种丰富度指数只是DIV指数中参数a =0时的一个特例。在存在自相似性的尺度范围内 ,利用分形维数可以对任意尺度上的群落α多样性进行较为准确地定量描述。以广东黑石顶自然保护区常绿阔叶林作为应用实例进行分析 ,结果表明 ,DIV指数与取样尺度在双对数坐标上的线性相关系数明显高于常用的Shannon指数和Simpson指数。     

Woody species diversity influences productivity and soil nutrient availability in tropical plantations

We investigated the relationship between plant diversity and ecological function (production and nutrient cycling) in tropical tree plantations. Old plantations (65–72 years) of four different species, namely Araucaria cunninghamii, Agathis robusta, Toona ciliata and Flindersia brayleyana, as well as natural secondary forest were examined at Wongabel State Forest, in the wet tropics region of Queensland, Australia. Two young plantations (23 years) of Araucaria cunninghamii and Pinus caribaea were also examined. The close proximity of the older plantations and natural forests meant they had similar edaphic and climatic conditions. All plantations had been established as monocultures, but had been colonised by a range of native woody plants from the nearby rainforest. The extent to which this had occurred varied with the identity of the plantation species (from 2 to 17 species in 0.1 ha blocks). In many cases these additional species had grown up and joined the forest canopy. This study is one of the few to find a negative relationship between overstorey plant diversity and productivity. The conversion of natural forest with highly productive, low-diversity gymnosperm-dominated plantations (young and old Araucaria cunninghamii and Pinus caribaea) was found to be associated with lower soil nutrient availability (approximately five times less phosphorus and 2.5 times less nitrogen) and lower soil pH (mean = 6.28) compared to the other, less productive plantations. The dominant effects of two species, Araucaria cunninghamii and Hodgkinsonia frutescens, indicate that ecosystem functions such as production and nutrient availability are not determined solely by the number of species, but are more likely to be determined by the characteristics of the species present. This suggests that monoculture plantations can be used to successfully restore some functions (e.g. nutrient cycling and production), but that the level to which such functions can be restored will depend upon the species chosen and site conditions. Electronic supplementary material The online version of this article (doi:) contains supplementary material, which is available to authorized users.     

Vegetation changes along gradients of long-term soil development in the Hawaiian montane rainforest zone

The development of the Hawaiian montane rainforest was investigated along a 4.1-million-year soil age gradient at 1200 m elevation under two levels of precipitation, the mesic (c. 2500 mm annual rainfall) vs. wet (>4000 mm) age gradient. Earlier analyses suggested that soil fertility and foliar nutrient concentrations of common canopy species changed unimodally on the same gradients, with peak values at the 20,000–150,000 yr old sites, and that foliar concentrations were consistently lower under the wet than under the mesic conditions. Our objectives were to assay the influences of soil aging and moisture on forest development using the patterns and rates of species displacements. The canopies at all sites were dominated by Metrosideros polymorpha. Mean height and dbh of upper canopy Metrosideros trees increased from the youngest site to peak values at the 2100–9000 yr sites, and successively declined to older sites. A detrended correspondence analysis applied to mean species cover values revealed that significant variation among sites occurred only on one axis (axis 1), for both soil-age gradients. Sample scores along axis 1 were perfectly correlated with soil age on the mesic gradient, and significantly correlated on the wet gradient. Higher rainfall appeared to be responsible for the higher rates of species turnover on the wet gradient probably through faster rock weathering and greater leaching of soil elements. We concluded that the changes in species cover values and size of the canopy species was a reflection of the changing pattern of nutrient availability associated with soil aging.     

松嫩平原盐碱植物群落种子库的比较分析

本文对松嫩平原碱化草甸6种单优盐碱植物群落土壤中有发芽力的种子贮量及其物种多样性进行了比较分析。虎尾草群落、角碱蓬群落、翅碱蓬群落3种一年生植物群落所具有的共同特征,表现为种子库存量大,优势种的种子数量占绝大多数,种子库的物种多样性指数相对较小。星星草群落和獐毛群落这两种过渡性的多年生群落,地上优势种均为种子库中的优势种,种子库的物种多样性指数趋于中等。羊草群落与其他演替阶段的群落相比,种子库存量最小,种子库的物种多样性指数最大。     

A review on the relationships between plant genetic diversity and ecosystem functioning北大核心CSCD

The loss of genetic diversity is accelerating due to habitat loss and population reduction caused by global change and anthropologenic activities. For species-poor ecosystems, the effect of genetic diversity on ecosystem functioning may not be smaller than that of species diversity. Therefore, understanding the relationship between genetic diversity and ecosystem functioning (GD-EF) and its underlying mechanisms is important for biodiversity conservation, responses of ecosystems to environmental change and ecological restoration. Here, we reviewed the studies on the effects of plant genetic diversity on ecosystem structures (community structure of the higher tropic level) and ecosystem functions (primary production, nutrient cycling and ecosystem stability), and the mechanisms underlying these relationships. We also discussed the influence of functional diversity on GD-EF, the comparison of effects of the genetic and species diversity on ecosystem functioning, and the application of GD-EF in the ecological restorations. We finally pointed out the limitations in current studies to provide references for the future: (1) further studies on the mechanisms of GD-EF are needed; (2) no study has evaluated the influence of genetic diversity on maltifunctinarity; (3) the impacts of different measurements of genetic diversity on ecosystem functioning are unclear; (4) there are lack of long-time GD-EF studies and GD-EF studies conducted at multidimensional scales; (5) the relative importance of genetic diversity and other factors on ecosystem functioning in the nature is unclear. © 2018 Editorial Office of Chinese Journal of Plant Ecology. All Rights Reserved.     

Development of modern benthic ecosystems in eutrophic coastal oceans: The foraminiferal record over the last 200 years,Osaka Bay,Japan

The ecosystem dynamics of a modern benthic community in Osaka Bay was studied by analyzing sediment cores and fossil foraminifera deposited during the past 200 years. The results suggest that the high-density/low-diversity assemblage has appeared in the early 1900s, coinciding with the eutrophication of the bay resulting from the Japanese industrial revolution. This assemblage proliferated during the period 1960 to 1970 when the eutrophication and bottom-water hypoxia were most pronounced. The development of the assemblage has been characterized by an increase in the relative and absolute abundance of eutrophication-tolerant species (Ammonia beccarii, Eggerella advena, and Trochammina hadai) and a decrease in many other foraminiferal species, such as Ammonia tepida, Elphidium, Miliolinella subrotunda, and Valvulineria hamanakoensis, that are unable to tolerate low-oxygen conditions. Approximately thirty years after the imposition of discharge restrictions in the 1970s, this assemblage continues to predominate in the inner part of the bay, and E. advena is currently found across the entire bay. These records make a significant contribution to understanding the long-term relationship between anthropogenic impact and ecosystem change.