As one of the key soil invertebrates, earthworms can greatly impact soil processes, and thus was named as “ecosystem engineer”. Earthworm activities such as feeding, digestion, excretion, and burrowing, facilitate the formation of various drilosphere in their guts or soils around, through which they alter the biological, chemical and physical processes of the ecosystem. Earthworms act as consumer, decomposer and modulator in ecosystem. The ecological functions of earthworm include: (1) effects on key soil ecosystem processes such as decomposition of soil organic matters and nutrient cycling; (2) effects on soil chemical and physical properties; and (3) interaction with plants, microorganisms and other animals. Earthworm activities and their functions in ecosystem are determined by various factors such as ecological groups of earthworms, population size, vegetation, parent materials of soil, climate, time scale, and history of soil utilization. The development of earthworm ecology was constrained by the complex feature of soil, the scarce knowledge of natural history and biogeography of earthworms, and the low efficiency of approaches in field manipulation of earthworm community. We suggest that new technologies such as the C and N isotope technique for nu-trient cycling and the image analysis approaches for soil micro-structure should be applied on earthworm ecological research in order to better understand the functions of earthworms.

Based on the environmental variables that associated with species’ occurrence records, ecological niche modeling (ENM) seeks to characterize environmental conditions suitable for a particular species and then identify where suitable environmental habitats are distributed in the space. Recently, ENM has been used increasingly in biological invasion, conservation biology, biological responses to climate change, disease spatial transmission, and variety aspects of ecology and evolutionary biology research. However, the theoretical background of these applications is generally poorly understood, leading to artifactual conclusions in some studies (e.g. niche differentiation during species’ invasion). In this paper we discuss the relationship between niche and geographic distribution and introduce the theoretical basis of ENM, along with relationships between the niche and ENM. Abiotic/biotic, historical and dispersal factors are three key elements that determine species’ geographic distributions at different scales. By using environmental variables derived from distributional records, ENM is based on observations that already include effects of biotic interactions, therefore ENM is used to characterize somewhere between the realized niche and potential niche, not the fundamental niche. Grinnellian and Eltonian niches are both manifested in ENM calibration, depending on the types of variables used to fit model, the natural spatial scale at which they can be measured, and the dispersal of individuals throughout the environment. Applications of ENM in understanding ecological requirements of species, discovery of new species or populations, nature reserve design, predicting potential invasion, modeling biological responses to climate change, niche conservatism, and species delimitation are discussed in this paper.

We used the literature, field investigations, specimen records and taxonomic research to categorize 515 alien invasive plant species from 72 families and 285 genera reported from China according to their biological and ecological characters, extent of spread within China, and amount of damage caused. Each species was put into one of 5 categories: malignant invasion (34 species), serious invasion (69 species), local invasion (85 species), general invasion (80 species), and species requiring further observation (247 species). According to our analyses of geographic distributional patterns, Chinese alien invasive plants were highly concentrated in the southwestern and eastern coastal provinces of China, and were rapidly spreading to inland China. These categories and distributional patterns of alien invasive plants could help to assess and control their invasive risk. Our results provide baseline information on Chinese alien invasive plants; and, at the same time, we put forward preliminary suggestions for further study, public education and the management of the important alien invasive plants in China.

Alien invasive species have become a serious environmental issue throughout the world. It is necessary to launch a nationwide investigation on alien invasive species, so as to obtain baseline data, identify causes of invasion, and put forward effective control strategies and measures. Data on classification, origin, pathway and environmental impacts of alien invasive micro-organisms, invertebrates, amphibians and reptiles, fish, birds, mammals, weeds, trees in terrestrial and aquatic ecosystems and alien invasive species in marine ecosystems of China were analyzed, based on literature research, field survey and consultation. 283 alien invasive species have been identified in China, and the number of species of alien invasive micro-organisms, aquatic plants, terrestrial plants, aquatic invertebrates, terrestrial invertebrates, amphibians and reptiles, fish, and mammals were 19, 18, 170, 25, 33, 3, 10, and 5, respectively. The proportion of alien invasive species originating from America, Europe, Asia, Africa and Oceania were 55.1%, 21.7%, 9.9%, 8.1% and 0.6%, respectively. Many institutions and individuals in China lack adequate knowledge of ecological and environmental consequences caused by alien invasive species, with some blindness in the introduction of alien species. For instance, 50.0% of alien invasive plants were intentionally introduced as pasture, feed stock, ornamental plants, textile plants, medicinal plants, vegetables, or lawn plants. 25% of alien invasive animals were intentionally introduced for cultivation, recreation, or biological control. In addition, much effort has been made on introduction of alien species, and little attention has been paid to the management of introduced alien species, which may allow their escape into natural environments and potential threats to the environment. There are also gaps in the quarantine system in China. All invasive micro-organisms were unintentionally introduced, through timber, seedlings, flowerpots, or soil. 76.3% of alien invasive animals invaded through commodity or transportation facilities because of the failure of quarantine. It is recommended that quarantine measures should be strictly implemented. At the same time, the intentional introduction of alien species should be strictly managed and a system of risk assessment should be implemented.

As increasing attention has been paid to below-ground ecosystems in recent years, the impact of exotic plant invasions on soil ecosystems has emerged as a central issue in invasion ecology. In this paper, effects of exotic plant invasions on soil biota and soil nutrient cycling processes are reviewed, and the mechanisms that underlie these impacts are discussed. The available literature suggests that no consistent pattern exists on the impacts of exotic plant invasions on soil microbes, soil animals, soil carbon cycling and nitrogen cycling. The mechanisms underlying the impacts of exotic plant invasions are also complex and diverse. The discrepancies most likely arise from the differences between invasive and native plants in a variety of physiological and ecological traits, such as litter quality and quantity, root distribution, and phenology. Future studies are recommended to (a) compare the impacts across multiple scales and multiple ecosystems; (b) intensify mechanical studies of the impacts; (c) link the impacts on biodiversity and ecosystem processes; and (d) explore the mutualistic interactions between soil ecosystems and exotic plants.

Ecological niche models (ENMs), which are widely employed to predict the potential geographic distribution of species, provide an important tool to quantify the risks imposed by invasive alien species. The problem of how to evaluate the performance of different models has attracted more and more attention. In the present paper, we introduced the principle of the method of Receiver Operating Characteristic (ROC) curve analysis in assessing the accuracy of different ENMs. We predicted the suitable distribution area of Radopholus similis, an important banana toppling disease nematode, with five widely used ENMs and evaluated the performance of different models by ROC curve analysis. The area under ROC curve (AUC) for BIOCLIM, CLIMEX, DOMAIN, GARP, and MAXENT models was 0.810, 0.758, 0.921, 0.903, and 0.950, respectively. Among these, the biggest value of AUC was assigned to MAXENT, indicating that the result gained by MAXENT should be better than the other four models. According to the results of analysis of variance (ANOVA), there was a remarkable difference in AUC between each model except for DOMAIN and GARP.

Roads serve multiple functions that enhance exotic species invasion. In this paper, we examined the roles of disturbance, light availability, slope aspect, and climate in explaining density and frequency of exotic invasive plants. We analyzed the effect of main environmental factors along 13 roads with different levels of anthropological disturbances (heavy, moderate, and light) in the north tropical and south subtropical mountainous zones in Yunnan Province. The results demonstrated that density of four species, Eupatorium adenophorum, E. odoratum, Ageratum conyzoides and Tithonia diversifoli, and frequency of E. adenophorum were significantly associated with distance from roads. The curves of these four alien plants all presented a single-peak pattern, and their maximum abundance occurred within 4 m of roads. These four alien plants invaded native plant communities from primary colonization points along road margins. Density of E. adenophorum, E. odoratum, A. conyzoides, T. diversifoli and Synedrella nodiflora and frequency of E. adenophorum, E. odoratum, A. conyzoides and T. diversifoli tended to be significantly higher along highly disturbed roads than moderately and lightly disturbed roads, indicating that plant communities adjacent to highly disturbed roads might be more prone to invasion. Density of E. adenophorum, E. odoratum and A. conyzoides and frequency of E. adenophorum, A. conyzoidesand S. nodiflora were significantly higher in areas with high light level than those that had medium or low light levels. E. adenophorum, E. odoratum and A. conyzoides might obviously invade farther in habitats along roads that had high light level. Density of E. adenophorum, A. conyzoides and S. nodiflora were significantly higher on warm aspects than on cool aspects. E. adenophorum and T. diversifoli were mainly distributed in the south subtropical mountainous zones, while E. odoratum and S. nodiflora were mainly in the north tropical mountainous zones. A. conyzoides and Malvastrum coromandelianum were distributed in both zones. Tridax procumbens were very few along roadsides, which had no statistical significance. Management of roadside habitats should be considered a key to preventing and controlling alien plant invasion, and the maintenance of a dense canopy of native vegetation would benefit control of alien invasive plants.

Spartina alterniflora，originating in North America, has been introduced to China and has now invaded many inter-tidal zones of gulfs and estuaries in China. With its spread, Scirpus mariqueter,a native grass species, has experienced a concurrent decrease in area. Based on field investigation at Chongming Dongtan Wetland and potted plant competition experiments at Fudan University, we compared growth characteristics and relative competitive ability between the two species. The results indicated that in terms of height, coverage, above-ground biomass, below-ground biomass, and mean seed number per spike, values for Spartina alterniflora were all significantly higher than those of Scirpus mariqueter.However, the density and number of flowering tillers per square meter for Spartina alterniflora were significantly lower than those of Scirpus mariqueter.In terms of seed output per square meter and seed germination rate, there were no significant differences between the mature populations of the two species. Both interspecific and intraspecific competition between Spartina alterniflora and Scirpus mariqueter remarkably reduced the number of ramets, the proportion of fruiting ramets, the above-ground biomass and the number of corms (only Scirpus mariqueter has corms). The interspecific relative competitive ability (measured as relative neighbour effect index, RNE) of Spartina alterniflora was significantly greater than that of Scirpus mariqueter. The obvious growing advantage of Spartina alterniflora compared with Scirpus mariqueter might explain its greater interspecific competitive ability, which might explain its successful invasiveness into the native Scirpus mariqueter community in the Yangtze River estuary.

The impacts and invasion method of alien invasive species (AIS), and prevention and management of biological invasion are discussed. Biological invasion is becoming one of the most important factors threatening biodiversity and stability of various ecological systems in China. The impacts of these biological invasions are becoming a more serious problems with development and increase of global trade, transportation, international travel and ecological tourism. Harmful AIS often leads to irreversible species extinction, and results in substantial economic losses within managed and natural ecosystems, including agriculture, forestry, fishery and animal production. Newly invading weeds, insect pests and plant diseases frequently result in large scale outbreaks and persistent use of chemical pesticides. Successful invasion and spread of some major insect pests and weeds in China were caused by man made factors. These include decision mistakes and unintentional introduction of some plants, such as water hyacinth and alligator weed as pig food, irresponsible introduction actions taken by individual/group without any ecological concerns, and lack of rapid response mechanism for eradicating potentially AIS as soon as they appear. China is an agricultural country. Any biological invasion will be a "big bomb" for our agriculture and inevitably result in ecological and economic losses in specific ecosystem and specific geographic regions. Prevention of biological invasion is an important aspect for safeguarding the state′s ecological safety. Development and researches should focus on building the state capacity, research capacity, and management capacity for addressing AIS problem. Based on the urgent situation of AIS in China, priority for research and action plans concentrate on: developing methods to identify the origin and pathways of invasive population; understanding the biological and ecological bases of AIS; developing environmentally friendly methods for control of AIS; developing environmental impact assessment and risk analysis methods for AIS; and developing methods for the recovery of habitats after control of AIS.

Remote sensing, in conjunction with Geographical Information Systems (GIS) and Global Positioning Systems (GPS), has been used successfully in many studies on coastal resources, dynamical monitoring of the environment, and quantifying tidal flat vegetation. We investigated the potential of using multispectral satellite remote sensing to map and quantify an exotic plant, Spartina alterniflora, on tidal flats in Shanghai. A Landsat5-Thematic Mapper image, dated 2^nd August 2003, was geometrically corrected using ERDAS Imagine 8.6, and a sub-sample of the study area was then extracted. The sub-image was then analyzed using a Tassel Cap transformation (K-T) and the Normalized Difference Vegetation Index (NDVI) was used to identify different types of salt marsh vegetation. Based on these results, a series of classes were identified and a supervised classification was carried out using the Maximum Likelihood Classifier in ERDAS Imagine. The results of the classification were then checked using an in situ field survey of selected areas. The classification had an overall accuracy of 80%. The classified image was then integrated with other data in a GIS to analyze the spatial distribution of the S. alterniflora communities in Shanghai. The results showed that the total area of the S. alterniflora community in Shanghai was 4,553.37 hm² in 2003, which accounted for 22.1% of the total vegetation on tidal flats. Excepting Chongming Xitan and Hengsha Island, the S. al-terniflora community was distributed extensively on the tidal flats in the Changjiang Estuary. Nanhui Bian-tan accounted for 2,069.01 hm²; Chongming Dongtan, 910.17 hm² and Jiuduansha, 769.05 hm². The distribu-tion pattern of S. alterniflora showed that anthropogenic transplantation and the rapid proliferation of clones could be the main cause for successful expansion of this exotic. The results of this research indicate the po-tential of this approach for providing timely data for quantitative inventory of invasive plants over large ar-eas, and a scientific basis for biodiversity protection and sustainable utilization of tidal flats resources.

Water hyacinth (Eichhornia crassipes), a noxious invasive species, has infested vast aquatic ecosystems. Besides its extraordinary adaptive ability and clonal growth, the eutrophication of water bodies also account for its rapid spread. Based on a series of pot experiments, we examined the growth characteristics of water hyacinth at three different nutrient levels, as well as its competitive effects on two native plants Ludwigia peploides ssp. stipulacea and Hydrilla verticillata. Our results showed that the mean number of ramets, mean height and total biomass of water hyacinth significantly increased with increase of nutrient level, indicating that nutrient-enriched water accelerated the growth and propagation of water hyacinth, which, as a result, reduced the growth of L. peploides ssp. stipulacea and H. verticillata. This suggests that eutrophication further boosts the competitive advantages of water hyacinth over native plants, and thus facilitates the invasion of this weed in water bodies. Thus, alleviating water pollution is a key method for controlling the spread of water hyacinth in order to protect native biodiversity and ecosystem function.

The flora of Hong Kong has been well-surveyed since the mid nineteenth century and has had a long history of alien plant invasions. To the present day, more than 2130 wild plant species have been recorded, including 238 species that are probably naturalized alien species. Among them, Mikania micrantha, Ipomoea cairica, Eupatorium catarium, and Panicum maximum are most abundant. Naturalized alien plants are most prominent in human-disturbed habitats, such as abandoned farmland, wasteland and roadsides, and are rarely important in relatively undisturbed forest habitats, or in fire-maintained impoverished shrubland and grassland. Impacts of naturalized alien plants on local ecosystems are so far limited to lowland habitats, including wetlands and forest margins, where they form monospecific thickets, outcompete native plant species, and reduce local habitat and animal diversity. The biggest impact on the local flora by an alien species, however, was caused by the Pinewood Nematode introduced in the 1970s. Introduction of alien vertebrates may also have an impact on Hong Kong's vegetation. As the biggest port on the southern coast of China, Hong Kong has probably been an important entry point for alien species to China. Among Hong Kong's naturalized alien plants, some have only recently been noticed, and have few or no records from the mainland. The potential for these species to invade the mainland should not be neglected. Appropriate measures to control spread of these plants, both locally and regionally, are essential.

The six meetings of the Conference of the Parties to the Convention on Biological Diversity held in 2002 adopted the goal of “significantly reducing the rate of biodiversity loss worldwide by 2010”, and requested Parties to develop biodiversity assessment indicators and to conduct biodiversity assessment. This paper puts forward five indicators for comprehensive biodiversity assessment, i.e. species richness, diversity of ecosystem types, completeness of vertical stratification of vegetation, endemism, and extent of biological invasions, based on the principles of scientific approach, representativeness, and practicality. Methods for comprehensive biodiversity assessment were established, and a national biodiversity assessment was con-ducted by taking 31 provinces (including municipalities and autonomous regions) as the basic assessment units. Biodiversity of provinces was classified into four grades. Yunnan, Sichuan and Guangxi boast highly rich biodiversity. Guizhou, Hubei, Guangdong, Hunan, Chongqing, Fujian, Tibet, Jiangxi, Zhejiang, Hainan, Gansu, Xinjiang, and Shaanxi boast quite high biodiversity. Henan, Anhui, Shandong, Shanxi, Hebei, and Beijing have moderate biodiversity. Jilin, Inner Mongolia, Shanghai, Liaoning, Ningxia, Qinghai, Jiangsu, Heilongjiang, and Tianjin have poor biodiversity.

As one of the five major global environmental problems, invasive species have posed serious threats to native ecosystems, public health, and regional economies. Although much progress has been made in the field of biological invasions research in China over the last decade, there are still large knowledge gaps. This paper reviews progress in the field of biological invasions research since 2000 as it relates to China, covering the diversity, colonization and immigration patterns of invasive species, mechanisms and ecological effects of biological invasions, and management and control of invasive species. In China, 529 invasive alien species have been identified, which originated primarily from South and North America, and the major taxa included terrestrial plants, terrestrial invertebrates, and microorganisms. We found a higher prevalence of invasive species in the eastern and southern provinces, compared to the western and northern provinces in China. This pattern is likely due to the differences in the level of economic development and environmental suitability between the two regions. Moreover, with further economic development, China may face more serious biological invasions in the future. These invasions of alien species are largely the combined results of the interactions between the intrinsic traits of these species along with resource opportunities and disturbances by human beings. Many mechanisms are responsible for successful invasions of alien species, but phenotypic plasticity, adaptive evolution, enemy release, interspecific mutualism or commensalism, and new allelochemicals may be primary causative factors. Biological invasions in China have caused serious impacts on native ecosystems, including biodiversity and ecosystem services, alteration of biogeochemical cycles, threats to agricultural and forestry production, traffic and shipping, environmental safety, and public facilities. China has also made progress in the detection and monitoring of invasive species, risk analysis, biological control, radical elimination, and ecological restoration of degraded ecosystems. We suggest several issues that need to be addressed in invasive species research in the future, including territory-wide inventories, evolutionary ecology and genomics, direct and indirect ecosystem-level consequences, interactions between major components of global change and biological invasions, and management and control technologies.

Biotic homogenization is the process whereby the genetic, taxonomic and functional similarity of two or more biotas increases over time. As a new research agenda for conservation biogeography, biotic homogenization has become a rapidly emerging topic of interest in ecology and evolution over the past decade. However, research on this topic is rare in China. Herein, we introduce the development of the concept of biotic homogenization, and then discuss methods to quantify its three components (genetic, taxonomic, and functional homogenization), and their driving mechanisms. Species invasions and extinctions are the root cause of biotic homogenization, whilst other habitat alterations that facilitate these two processes, such as environment degradation and disturbance, urbanization, and habitat homogenization, also influence biotic homogenization. Biotic homogenization was tempo-spatial-scale dependant. The homogenization degree differed between various ecosystems and taxa, as well as in different regions. We also reviewed ecological and evolutionary consequences and effects on human dimension (economics and biodiversity conservation) due to biotic homogenization. Considering the distinctness of China’s biodiversity, we suggest that it is time to strengthen research on biotic homogenization in China. In our view, the most fundamental need is to establish open, reliable databases to foster biotic homogenization research. We hope this review will stimulate biotic homogenization research in China.

How the traits of invasive plants determine their invasiveness is one of the major issues in invasion biology. Invasive plants usually have broad ecological amplitudes, and hence can exploit a great diversity of habitats. Genetic differentiation and phenotypic plasticity are two major strategies that invasive plants can use to invade broad geographical areas and diverse ecosystems. Phenotypic plasticity is a trait that has a certain genetic basis and can evolve independently. Although some of the invasive plants have low genetic variation, they can still invade diverse habitats. Phenotypic plasticity may play a critical role in invasion of these species into new environments. In this review, the concept of phenotypic plasticity and its significance for adaptation were introduced. The relationship between phenotypic plasticity and the invasiveness of alien plants was discussed, supported by theoretical analysis and published experimental evidence.We also suggest some issues that might be addressed in future studies for better understanding of the mechanisms of successful invasion with reference to phenotypic plasticity. Although successful invasion cannot be explained by phenotypic plasticity alone, the positive correlation between invasiveness and phenotypic plasticity seems to be a rule rather than an exception for those invasive species with low genetic diversity but a broad geographic distribution.

Alternanthera philoxeroides is a perennial herbaceous amphibious aquatic weed of the family Amaranthaceae, native to South America. It was first found in Shanghai, China in 1892. After a stagnant phase of 50 years (1890s-1940s), A. philoxeroides spread rapidly throughout areas of central and southern China, and the range is still expanding. It is one of the most harmful and widely distributed alien species in mainland China. We applied Genetic Algorithm for Rule-Set Production (GARP) ecological niche modeling to predict the species’ potential range in China on the basis of occurrence points within colonized areas whereA. philoxeroides had reached equilibrium. Environmental factors such as slope, flow accumulation, mean annual temperature, annual precipitation greatly influenced the size of A. philoxeroides’s potential range, while parameters such as solar radiation and elevation had little impact. Areas that we predict to have potential for invasion were still larger than those areas that had been invaded. Therefore,A. philoxeroides is predicted to continue to expand in China. Most Chinese provinces excluding Tibet, Qinghai, western Sichuan, southern Xinjiang, western Gansu, north-eastern Inner Mongolia, Jilin, Heilongjiang and Hainan are likely to be invaded. Because they are adjacent to areas that had been invaded, Shaanxi, Shanxi and south-eastern Gansu were most liable to be invaded; hence urgent measures should be taken there to prevent this species from further spreading.

An overview of research progress of urbanization impacts on plant biodiversity was given. With a worldwide expanding of urbanization, especially in developing countries, effects of urbanization on biodiversity are attracting more attention. Urbanization reduces native plant species whilst increases introduced plant species. As for distribution of plant species, richness of native plant decreases along rural, rural-urban fringe and urban gradient. However, richness of introduced plant species increases, which results in increasing of total plant species richness along the same gradient. Urbanization also produces the great influence on plant species composition and makes the dominant species varying along the gradient. The mechanism of urbani-zation affecting plant biodiversity mainly lies on three aspects, i.e., introduction of exotic species, change of microhabitat, and altering of landscape pattern. Concerning further researches, four main trends will become more and more important: (1) systematical integration of different regions, various methods and multi-disciplines, (2) long-term site monitoring the urban expanding and plant biodiversity changing, (3) re-search on interior mechanism of native plant species’ loss and characteristics’ change, especially the in-ter-actions between the exotic and native plant species, and (4) urban plant biodiversity conservation.

In recent years, tourism has developed rapidly in Jiuzhaigou Nature Reserve, which has been designated a World Heritage Natural Site. To measure the effect of tourism on vegetation in Jiuzhaigou, we selected two scenic spots, namely the Virgin Forests and the Grass Lake, as study sites and compared the species composition and diversity of understory plants in Abies fargesii var. faxoniana forest. The results showed that (1) the species composition and their frequency were significantly impacted by tourism. Some native shade-tolerant or hygrophilous plants had disappeared, while some xerophilous, disturbance-resistant species, as well as some exotic and synanthropic species, had expanded their populations. (2) In the Virgin Forests, the coverage of understory plants was reduced and the shrubs and bryophytes were markedly depressed (both in height and density). In the Grass Lake, which was only slightly disturbed, there were no obvious effects on herbaceous and shrub communities except for bryophyte. It is concluded that bryophytes are more sensitive to the degree of tourism disturbance, and the species composition can be a better indicator for disturbance degree than other indices such as height, coverage and density. The results indicate that tourism in Jiuzhaigou had an obvious negative effect on the indigenous biodiversity, and conflicted with biodiversity conservation. Therefore, it is necessary to restrict tourism activities to an appropriate extent.

The impacts of invasive alien species on the genetic diversity and evolutionary responses of native species are poorly understood. Accumulating evidence shows that invasive plant species can lead to genetic erosion of natives directly through hybridization and gene infiltration, or even affect genetic diversity of natives through creation of new “genotypes”. Exotic species can also alter genetic diversity of natives indirectly through habitat fragmentation and modification, processes which influence gene flow within and among populations and result in inbreeding and genetic drift. On the other hand, some studies show that native species can respond evolutionarily to invasive plants, thereby reducing or eliminating invasive impacts. While interacting with invasive species, native species in both above- and below-ground ecosystems exhibit a series of evolutionary events such as adaptation, speciation or extinction. To more comprehensively evaluate the ecological impacts of biological invasions and the adaptive potential of natives, here we review the impacts of invasive plants on biological (genetic) diversity of native species, and the evolutionary responses of natives. We also discuss relationships between the genetic and evolutionary responses of natives and the success of invasive plants, and propose topics for further research.

A list of invasive alien species (IAS) is essential for initiating an analysis of the biological and ecological traits of such species and for improving our understanding of patterns of biological invasions. An inventory of IAS in Shanghai was prepared through a literature survey. A total of 212 IAS belonging to 63 orders and 87 families were recorded. Of these, 65% were plants, 29% were animals, and the rest were microorganisms. Dominant groups could be distinguished in both plant and animal groups. Species originating from the Americas made up 51% of the total, while 52% of plant species were introduced intentionally and 82% of animal species unintentionally. Of the invasive plants, 93% are distributed in highly disturbed habitats with rich resources, whereas 76% of invasive animals occur in storehouses and farmlands. The present information on diversity and ecological features of IAS is crucial for designing management strategies against the negative impacts of such species in Shanghai.

The pine wood nematode (Bursaphelenchus xylophilis) has been causing widespread losses to pines in China since it was first found in 1982. It can bring about forest degradation. To study the effect of 　nematode-induced forest succession on avian communities, we chose three forest types at different seral stages, including evergreen broad-leaved coppice infested by the pine wood nematode for five years and ev-ergreen broad-leaved forest infested for 12 years, both from Xiangshan County, Zhejiang, and one 40-year-old evergreen broad-leaved forest from Tiantong National Forest Park, Zhejiang. The results showed that bird species richness and diversity were significantly greater in the two infested evergreen broad-leaved forest types with little difference between them, while there existed little difference in bird abundance and evenness in the three types. It suggested that the evergreen broad-leaved forests at early successional stage had higher bird species richness and diversity. Stepwise multiple regression models of bird community vari-ables indicated that microhabitat feature such as stand age was an important predictor of bird community composition.

Rapid worldwide urbanization during the last century has led to more than half the world’s population living in urban regions. Studies of how urbanization affects insect diversity have focused on the following: insect abundance, distribution, extinction, food habits and ecosystem services. Native insect populations have declined greatly in urban areas, where studies of their spatial distribution have revealed that abundance decreases along what is termed the rural-city center gradient (RCG), many native insects even extinct with urbanization process. Most specialist insect communities have declined in abundance due to urbanization, while some generalist species, such as aphids, cockroaches and termites, have increased slightly in abundance. It is also the case that herbivorous, parasitic, saprophagous and flower-visiting insects are much more negatively influenced by urbanization than predator insects. This has a significant effect on the ecosystem services of insects. The decline of many insects due to urbanization can be attributed to environmental pollution (including air pollution, water pollution, light pollution, and heat pollution), habitat fragmentation, road hardening, clustering of buildings, and occurrence of introduced invasive species. As urbanization continues, measures should be taken to protect insects in urban areas. This will entail improving basic scientific research on the problem, construction of suitable habitats, and informing the general public of the benefits of environmental protection.

In order to reveal the impacts of Spartina alterniflora invasion on macrobethos communities, during October 2004 to January 2005, we studied the distribution pattern of macrobenthos and its correlation with soil factors in Jiuduansha intertidal mudflat of the Yangtze River estuary. We selected 57 sample sites representing six habitat types, i.e., Phragmites australis, Scirpus mariqueter, S. triqueter, and Spartina alterniflora plant communities, and low tidal and high tidal mudflats. A total of 28 macrobethos species were found, consisting of Mollusca, Annelida, Crustacea, and Insect larva, with the dominant species being Stenothyra glabra, Assiminea violacea, A. latericea, Limnodriu hoffmeisteri, and Ilyrplax deschampsi. The low tidal mudflat supported more species abundance of macrobenthos, but low density, whereas the habitat of Scirpus mariqueter held the highest density. Statistical analysis demonstrated that Pielou evenness index significantly differed between bulrush areas (Scirpus mariqueter) and other habitat types. Further analysis revealed that habitat dominated by the invasive species Spartina alterniflora supported average species richness and density of macrobenthos, although some species were absent.

During May to July, 2006 and April to May, 2007, we studied pollination biology in Ipomoea cairica, an invasive weed in Guangdong Province, China. Ipomoea cairica is a perennial creeping or climbing herbaceous vine, blooming all year round in Guangdong. The flowers gathered in cymes, with a purple or bluish purple bell-formed corolla. The petals unfolded at about 4:30–5:20 and closed at 17:40, lasting for about 12 hours. The proximity of the stigma and anthers during flowering period facilitated the transfer of self-pollen. The mean volume of nectar per flower was 5.82 ± 2.47 μL (n = 10), with a sugar concentration of 41.03 ± 6.52% and an amino acid concentration of ca. 0.042 mg/mL. During anthesis, both pollen viability and stigma receptivity remained at a high level (>90%). The mean P/O ratio was 4,778.18 ± 264.58 (n = 10). Carpenter Bees (Xylocopa sp.) were considered as effective pollinators, while flies and butterflies were occa-sional visitors. Ipomoea cairica is self-incompatible as determined by an absence of fruit set in the flowers following controlled hand self-pollination, producing fruits and viable seeds only after cross-pollination.

The genotypes of 10 indigenous Chinese cattle breeds and three introduced breeds were investigated using 10 microsatellite DNA markers recommended by the Food and Agriculture Organization of the United Nations (FAO) and the International Society of Animal Genetics (ISAG) through fluorescence-multiplex PCR. The allele frequency, polymorphism information content (PIC), and heterozygosity were computed to estimate the genetic variation of each population. To determine the genetic relationships among the breeds, phylogenetic trees were constructed based on Nei’s genetic distance and Nei’s standard genetic distance using the unweighted pair-group method with arithmetic mean. As a result, 13 breeds were clustered into three groups. The first group belongs to the common cattle breeds including Yanbian, Changbai, Yanjiang, Monggol, Altay White Head, Hazake, Fuzhou, and Tibetan, while the second group contains those with zebu blood including Xigazê Humped and Apeijiaza. The third group consists of foreign breeds including German Yellow, Simmental, and Charolai. The results may provide a scientific basis for the study of characteristics of Chinese indigenous cattle breeds so as to preserve and utilize them.

Agricultural activities , such as land use , tillage , intercropping and rotation , grazing , and extensive usage of pesticides and fertilizers , exotic germplasms introduction , and screening of varying progenies in breeding program , have significant impacts on species diversity , genetic diversity of flora and fauna. Land use in an unreasonable way results in habitat fragmentation and biodiversity decrease. Species in soil were disturbed or became extinct on a large scale by tillage activities with agricultural machines. Extensive usage of pesticides causes loss of non2target insects and plants. Genetic erosion resulted from modern breeding program by means of limited interspecies hybridization decreases the genetic diversity of agroecosytem. Some agricultural activities such as intercropping , rotation , organic farming practice are favorable for biodiversity conservation. In most cases , agricultural activities focus only on crop production , while the impacts on wild plants and animals by agricultural activities are neglected. This paper provided an overview of the impacts of agricultural practices on biodiversity , and discussed how agricultural practices could be modified so as to enhance the conservation of biological resources and long term viability of agriculture.

Recent progress in studying mechanisms of biological invasion is reviewed involving several aspects , such as biological characteristics of exotic species , interaction among exotic species and their new neighbours , the relationships between species diversity and community resistance to invasion , the effects of changing ecological factors in new habitats. We also analyze the progress of research methodologies and some unsolved vague points in this field. According to recent studies , the mechanisms of biological invasion seem so diverse that no common pattern could explain all cases. A better understanding of invasive mechanisms is essential in developing ecological theory and significant in cont rolling exotic pests.

Fanjing Mountain is situated in Guizhou Province, southwestern China. Having the best preserved ecological system in the region, it has been designated as a national nature reserve. From 2001 to 2003, to explore the status and dynamics of the species diversity of fishes, we conducted three surveys in both the Wujiang River and the Yuanjiang River systems in the area around Fanjing Mountains. A total of 3,614 specimen were collected from 19 sites, belonging to 85 species/subspecies, 61 genera, 14 families, and 5 orders. Of these, Clarias fuscus is an introduced species while the others are indigenous. Pseudohemiculter hainanensis, Metahomaloptera omeiensis omeiensis, and Glyptothorax fukiensis fukiensis were newly recorded in this area. The fish fauna mainly comprised members of the family Cyprinidae of the order Cypriniformes, and fishes living in swift-flowing streams and small-sized species were dominant. Our study, combined with literature review, showed that indigenous fish species had decreased. Additionally, the species in Cypriniformes decreased much more than those in other orders in the area. The rapid decrease of species richness of indigenous fishes probably resulted from over-fishing and destruction of the river environment. Measures for protection of indigenous fish in this area are also discussed.

Biological invasion is recognized as one of the greatest threats to the global biodiversity because invasive exotic species not only alter the local environments but also have serious ecological effects on native species. Birds are positioned at high trophic level within the food web in the ecosystem, and thus any changes within the system can affect the birds in one way or another. The ecological effects of different exotic taxa like mammals, birds, invertebrates and plants on native birds are reviewed in this paper. In summary, the exotic species can affect native bird species in four main ways, 1) predation of birds or eggs by the exotic mammals; 2) competition for habitats and foods with exotic birds, and loss of genetic diversity by hybridization with the closely-related exotic species; 3) direct and indirect alterations of native habitats and food resources, and predation by the exotic invertebrates; and 4) loss and fragmentation of habitats for native birds through altering species composition and structure of native plant communities by exotic plants. The unsolved questions and future research directions in this field are also addressed.

Alligator weed (Alternanthera philoxeroides) is a notorious invasive alien species worldwide. How to limit its population expansion in terrestrial habitats has long been an intractable problem. To predict growth of alligator weed in local patches, a field planting experiment was performed. Using harvesting data, we established growth models of different growth variables; meanwhile, the allometric relationships of these variables were determined. The growth models of main stem length, biomass, leaf area and patch area all in-creased in an exponential pattern with growth period, and the daily growth rates (%) of main stem length, to-tal biomass, leaf area and patch area were 4.28, 11.27, 11.59 and 8.67, respectively. The result of allometric analysis showed that it was significantly correlated between all the growth variables. The allometric exponent b of shoot mass (x) vs. root mass (y) indicated that the root/shoot ratio decreased with the growth of the plant. From the allometric exponent b of main stem length vs. total biomass and of main stem length vs. leaf area, we could deduce that the total biomass and leaf area increased quadratic relative to main stem length, and in-creased proportionally to patch area. As for variables of biomass vs. leaf area, an isometric relationship was found, i.e. the canopy size kept relatively constant when plant size increased. Based on the relation between leaf area and biomass, leaf area ratio (LAR) and specific leaf area (SLA) of the alligator weed in terrestrial habitat were calculated, being 88.24 cm²/g and 287.97 cm²/g, respectively. These results provide basic data for future growth modeling further to effective and economical control.

Eupatorium adenophorum (Compositae), a highly invasive plant in southwestern China, has increasingly invaded the habitats of the gesneriaceous plants. All species of Gesneriaceae in China have been listed in China’s Red List and some of them have been categorized as the National Key Protected Species. To examine the possible allelopathic effect of E. adenophorum on Gesneriaceae, five species in three genera of Gesneriaceae (Chirita spinulosa, C. heterotricha,C. liboensis, Aeschynanthus acuminatus, and Titanotrichum oldhamii) were treated with three parts of E. adenophorum, i.e., aqueous root, stem, and leaf extracts (8%), respectively. The results indicated that aqueous leaf extracts of E. adenophorum had very different impacts on C. spinulosa, C. liboensis and C. heterotricha, of which it was the most obvious on C. spinulosa. Seedling growth of C. spinulosa were totally inhibited when aqueous leaf extracts 2.4%, 3.2% and 4.0%. The aqueous stem extracts of E. adenophorum showed some impacts on T. oldhamii. Seedling growth of T. oldhamii were inhibited 40% when the stem extracts of E. adenophorum was 1.6% . Aqueous leaf and stem extracts of E. adenophorum had little effect on seedling growth of A. acuminatus. However, aqueous root extracts of E.adenophorum also had no significant suppression on these five species. Therefore, our experiments con-firmed allelopathy of E. adenophorum on Chirita and Titanotrichum but not so much on Aeschynanthus. The gesneriaceous species on rocks seemed more susceptible to allelopathy of E. adenophorum than their allied species on trees.

In the context of increasing anthropogenic activities, nutrient enrichment and physical disturbances are among the most important environmental factors influencing biological invasions. On the other hand, clonal growth and vegetative propagation are considered important life history traits promoting the invasiveness of plants in high-resource and disturbed habitats. Alternanthera philoxeroides, endemic to South America, is an amphibious clonal weed invading areas worldwide. It is widely distributed in warm-temperate and subtropical regions, and tends to invade nutrient-rich and disturbed habitats such as riparian zones, wetlands, and arable areas. Throughout its introduced range, A. philoxeroides rarely produces viable seeds and reproduces mainly by vegetative propagation via storage roots and stems. Therefore, formation of storage roots, sprouting of root buds, and growth of new ramets are crucial characteristics in the life history of A. philoxeroides. We conducted three container experiments to examine the responses of vegetative propagation characteristics of A. philoxeroides to two factors—nutrient addition and physical disturbance (two types of physical disturbance: fragmentation and burial of storage roots). Nutrient addition increased total biomass and mean length of storage roots 1.5-fold, and biomass allocation to storage roots by 15% (i.e., vegetative reproductive allocation). Number of root buds increased by approximately 15 sprouts per g (dry mass) of storage root. Burial depth had no effect on number of sprouts per root fragment. Neither storage root size nor burial depth affected main stem length or mean relative growth rate of ramets. Our results suggest that adaptation of vegetative propagation characteristics to nutrient enrichment and physical disturbances may enable localA. philoxeroides populations to grow rapidly, and contribute greatly to the persistence of metapopulations at the watershed scale.

Crofton weed () seeds took a speculative strategy to germinate, and its seeds would germinate at any time all the year round as long as the conditions were suitable. The peak of the seeds’ germination occurred in the rainy season while few seeds germinated during the dry seasons. The un-flowering individuals of Crofton weed keep growing all year, and its growth rate would be influenced by the illumination intensity, humidity and temperature distinctly. The results showed that all of the growth pa-rameters of seedlings germinating during autumn changed slowly in the dry season. The optimum habitat was the sunny sites, then entirely shaded ones, and the shrub habitats were the last. The fastest growth of the seedlings period began in June and ended in October. Usually the seedling would flower and seed during the first dry season, but those germinated later or did not develop well would keep vegetative growth without flowering. The growth dynamic of un-flowering seedlings was similar to those flowering and seeding, but the life history periods between them were different: only those crossing two or enven more winters could the former seedlings bloom and fructify to finish their life history circle. The result of this study further indicated that reinforcement each other of both sexual reproduction and clone would promote the renewal and spread of their population increase of Crofton weed.

Plant invasions are unintended consequences of globalisation , which facilitates the transglobal movement of plant species across all geographical and physical boundaries with the vastly increasing movement of people and commercial goods. As an internationalised city that has various channels through which plant s′movements occur , Shanghai has been subject to a heavy invasion of plants. This paper firstly deals with some characteristics of plant invasions in Shanghai. It is concluded that : 1) alien plants play an important role in the flora of Shanghai , accounting for 57. 4 %of the total flora ; 2) annual and biennial plant s are the major component s of Shanghai′s alien flora , representing 69.1 %; 3) most alien plants belong to a relatively few families (e. g. Asteraceae and Poaceae) ; 4) monocotylous families tend to have a higher proportion of alien plants with respect to their world′s number of species than do dicotylous families ; and 5) plant invasions will continue to sweep across literally every part of Shanghai as the consequence of it s further urbanisation and increasing global trade (c. f . China′s ent ry into WTO by November 2001) . These patterns of plant invasions reflect the role of humans as global plant dispersers and of human disturbance in plant invasions. In the rest of the paper , we briefly review other issues in the field of plant invasions , including att ributes of invasive species , habitat invisibility , environmental and economic costs of plant invasions , and future research directions.

The leguminous Caragana species are important vegetation components, which are useful for rehabilitation of degraded ecosystems on the Loess Plateau, China. We studied the influence of seed predation by frugivores on the regeneration of two native leguminous species, C. licentiana and C. opulens, and one exotic species, C. intermedia. The results showed that before dispersal, 88.2% of the seeds of C. licentiana, 29.7%±1.7% of C. opulens, and 43.2%±4.8% of C. intermedia were infected by insects. After dispersal, 100% of the seeds of C. licentiana and C. opulens in all microhabitat were completely predated by seed predators in one to four days. Seed predation rate of C. intermedia was relatively low and differed with mi-crohabitats: 100% in shrub lands, 85.0%±10.0 in grasslands, and 31.0%±8.7% in open land. Seed predators greatly reduce seed quantity, seed dispersal and germination rate of C. licentiana and C. opulens. On the other hand, seed predators may effectively disperse the hard-coated seeds of C. licentiana, which may ex-plain why C. licentiana has become a dominant shrub species in Dingxi County, Gansu Province. Seed predators have little influence on the seeds of C. intermedia.

In order to examine the effects of the invasive plant Spartina alterniflora on insect diversity in Jiuduansha wetlands in the Yangtze River Estuary, we surveyed insects in monoculture stands of three species by net-sweeping and plant-harvesting methods from May 2004 to October 2005. A total of 11,300 insects were collected, belonging to 12 orders, 69 families and 97 species. We found that species number and Shan-non-Wiener index of the insect community in Spartina alterniflora monoculture were significantly lower than those in the two native monocultures (Phragmites australis and Scirpus mariqueter). However, Simp-son’s dominance index was higher in Spartina alterniflora monoculture. Cluster analysis indicated that, for both survey methods, the similarity of insect communities between Phragmites australis and Scirpus mari-queter was higher than that between Spartina alterniflora and the two native communities. We conclude that invasions of Spartina alterniflora might lead to reduction of insect diversity and alteration of insect commu-nity structure in Jiuduansha wetlands.

Cave fauna is an important component of biodiversity. Guangxi has the most spectacular Karst scenery in China beneath which lies a plenty of unexplored cave fauna. However, very little research has been carried out to document them. We collected and identified 180 cave animal specimens, from eight caves in Yachang Nature Reserve, Leye County, NW Guangxi between May and June of 2007. These specimens belonged to 4 phyla, 10 classes, 20 orders, 31 families, and 36 species/groups. Among them, cave crickets, millipedes and spiders are the most widely occurring animals, while Cololembola, Scolopendromorpha, the mosquitoes and flies of Diptera are widely distributed. Blattaria and Neuroptera are only occasionally found. There are more cave animals in wet or longer caves than in dry or shorter ones. In the same cave, dry segment has less cave animals than wet segment. In general, moderate temperature, high humidity, a stable cave environment and an absence of exotic invasive species provides an ideal habitat for cave animals. Unfortunately, we found that some caves have been seriously damaged due to the lack of conservation, which threatens the survival of cave fauna. To avoid loss of Chinese cave biodiversity, we should arouse public awareness of protecting the cave environment. Furthermore, laws of cave biodiversity protection should be made as soon as possible.