Conservation genetics deals with the genetic factors that affect extinction risk and genetic management regimes required to minimize these risks. In this review, we introduce the advance from the genetic diversity study and the influence of genetic diversity on ecosystem. Until now, most of conservation genetic studies still adopt selective neutral genetic markers, which generate a large amount of valuable information for conservation theory and practice. Two important implications of conservation genetics are introduced: (1) the identification of individuals, genetic unit or species, which is very important for conservation strategy making and efficiency improving; and (2) cryptic bottleneck caused by reproduction and dispersal limitation, which is often neglected in conservation practice. Generally, neutral genetic markers may not provide enough information for the genetic basis of species adaptation. In recent years, along with the development of genomics, more and more studies begin to investigate the genetic basis of adaptation by using adaptive genetic markers. Limited by lack of the functional gene information, most of these studies adopt the genome scanning approach. The development of landscape genetics promotes the understanding of the neglected relationship between genetic diversity and the landscape heterogeneity. In addition to the genetic diversity study itself, some studies found that plant genetic diversity may influence the ecosystem structure and function. This illustrates that genetic diversity in both endangered species and common species can play an important role to ecosystem integrity and sustainability. Finally, we briefly discuss how to integrate the genetic diversity into conservation practice more effectively. And, we also indicate the gap between Chinese and international advanced studies at the area of conservation genetics.
Ex situ conservation, complementary to in situ conservation, plays an important role in preservation and recovery of endangered species. Tsoongiodendron odorum is a relic species that was listed in the Second Grade of the List of Wild Plants Under State Protection (First Batch) in China. For protection of its genetic diversity, ex situ conservation populations have been established and managed outside of natural habitats in several nature reserves since 1980. However, only dozens of individuals are currently saved from each planted population. To assess the actual protective effectiveness of these planted populations, we detected and compared the genetic diversity of three planted populations from Nanling Mountains with four natural populations using ISSR markers. Overall, we detected 362 total ISSR discernible bands with 16 ISSR primers, of which 301 were polymorphic. The percentage of polymorphic bands (P) was 83.2%. At the population level, the percent of polymorphic bands ranged from 37.9% to 62.2%, with an average value of 53.1%. This result showed that T. odorum had high genetic diversity both at population and species levels. However, the percentage of polymorphic bands and Shannon information index (I) of ex situ conservation populations (66.6% and 0.2990) were much lower than those of natural populations (80.9% and 0.3629). We deduced that there was a narrow genetic base for plantations of T. odorum. Population structure analysis revealed that three planted populations could be collected from the same wild population (i.e., YK population). The genetic variation of four natural populations (GST=0.2495) showed that there was significant isolation among populations, which would limit gene flow and population differentiation among populations. We present suggestions on regulating seed collection from different natural habitats to establish planted populations and strengthening research on the reproductive biology of T. odorum.
Molecular ecology is an integrated scientific discipline that applies evolutionary theory to resolve various macroscopic biology questions. After approximately a half-century of development, it has become a well-established and active research field. It has not only penetrated numerous study areas of macroscopic biology, but also successfully bridged multiple disciplines such as ecology, physiology, geoscience and evolutionary biology. The research scope of molecular ecology ranges from developing the basic theories and methodologies, to uncovering and describing fundamental modes and patterns, to exploring processes and mechanisms, to excising research outcomes in practical applications such as conservation or pest control. The rising of molecular ecology has transformed macroscopic biology research, making it possible to leap into an epoch where systematical investigations on specific or general mechanisms are possible from joint genetic, ecological and evolutionary perspectives. Molecular ecology has already entered into the omic era, making many research dreams readily realisable. The omic era also brings challenges, of which the ones with the most profound influence on molecular ecology would be breakthroughs in basic evolutionary theories, such as theories of genetic variation, population differentiation, the evolutionary roles of epigenetic modification and variation, etc. Predictably, this will trigger an unprecedented revolution in biology, thus affecting undoubtedly all branches of ecology and even forging some new subdisciplines such as ecological epigenomics. For Chinese scientists, the opening of the omic era of molecular ecology has provided a rare and great opportunity for developing and establishing new methodologies, hypotheses and theories in macroscopic biology. Thus far, we have made no significant contributions. Nevertheless, theoretical, conceptual, and methodological research are the weakest areas of molecular ecology studies in China. Both research funding organizations and scientists should be clearly aware of the trends of research development and the challenges facing us; new funding management policies should be amended, and the proper research attitude and posture re-established.
Endemism, the restriction of a taxon’s distribution to a specified geographical area, is central to the study of biogeography. Understanding endemism not only concerns a number of evolutionary and biogeographical issues, but also plays an important role in maintaining biodiversity and in the selection of priority areas for conservation. In recent years, various measures and analytical methods have been used to investigate patterns of endemism for various taxa from different regions. The emergence of these new measurements has benefited from the construction of phylogenetic trees and the implementation of data from spatial statistics. Some of these measures, such as phylogenetic diversity, phylogenetic endemism, and biogeographically weighted evolutionary distinctiveness deserve much more attention. Here, we review progress in the methodology used to measure the distribution patterns of endemism. These metrics have generally developed from a single time or space perspective to space-time united patterns. Specifically, the metrics include species richness, phylogenetic diversity and evolutionary distinctiveness, plus all there in combination as well as the weight of species range size. Moreover, we propose that studies on the distribution patterns of Chinese endemic taxa should pay attention to species diversity, phylogenetic diversity, species β-diversity, and phylogenetic β-diversity. In particular, model simulation analysis should be emphasized and implemented during investigations. These studies will provide fundamental knowledge for comprehensive recognition of scale-induced differences and for the detection of mechanisms underlying the distribution patterns of endemic taxa, and therefore provide theoretical support for biodiversity conservation.
Microbes with rich species and genetic diversity are widely distributed throughout various habitats in the world. China possesses a variety of climate zones, geographic environments, and complex ecosystems, which play a large role shaping the complex biodiversity of this country. Microbial diversity has been widely studied and well documented by Chinese scientists. For example, a total of ca. 14,700 eukaryotic microbe species have been recorded, including ca. 14,060 fungi, ca. 300 oomycetes, and ca. 340 slime molds. Within the Fungi, there have been 473 medicinal fungal species and 966 edible fungal taxa recorded. However, recent studies have documented much high species diversity of prokaryotic microbes using molecular techniques, which have greatly promoted the study level of microbial diversity in China. This review paper summarizes recent research progress of microbial (i.e., archaea, bacteria, fungi, oomycetes, and slime molds) diversity in China based on traditional and molecular techniques.
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.
Spatial patterns of biodiversity are results of contemporary climate, disturbance, and geological history. In this paper, we review the historical hypothesis which explains historical importance in shaping biodiversity patterns, focusing on the recent development in its studies on mechanisms, parameter selection, and relative importance of historical factors versus contemporary climate. Based on literature research, we conclude that, (1) the historical events significantly affect the present patterns of biodiversity, and that these effects are masked by the strong collinearity between historical processes and contemporary climate; (2) historical processes are more significant in influencing distributional patterns of species with small ranges (or endemic species) than those of wide-spread species; (3) measurement of historical processes is a challenge in testing historical hypothesis, as the surrogates currently used are strongly collinear with contemporary climates. Phylogenetic analysis may be help assess the importance of historical hypothesis in controlling spatial patterns of biodiversity.
Exploring the mechanisms underlying community species richness is a key issue in ecology and conservation biology, and many hypotheses based on small-scale, local processes have traditionally been used as explanations. The species pool hypothesis developed by Zobel et al. suggests that the variation in community species richness is not only associated with contemporary environmental factors and ecological processes (e.g. competition and predation), but also limited by the regional species pool. The regional species pool is the set of species in a certain region that are capable of coexisting in a target community, which is shaped by historical (e.g. glaciation and geological age) and regional processes (e.g. speciation, immigration, dispersion, and extinction). The species pool hypothesis suggests that the larger the area of a habitat type and the greater its geological age, the greater the opportunity for speciation and hence the larger the number of available species adapted to that particular habitat, which will in turn lead to higher community diversity. The species pool is generally studied at two spatial scales: the regional and the actual scales. While the regional species pool is primarily determined by biogeographic processes, the actual species pool (species present in the target community) is determined by both ecological processes (e.g. competition) and the regional pool. In this review, we introduce and discuss the concepts relating to, and evidence for the species pool hypothesis, together with methods for estimating the species pool.
DNA barcoding technology provides molecular information, standard dataset platforms, and universal technical regulations for modern biological research. We briefly review the history of DNA barcoding between 2003 and 2012, and classify DNA barcoding into three types of biological function: basic function (e.g., storing data, and identifying species), extending function (e.g., building phylogenies, serving specific subjects, and compiling biological atlas) and potential function (e.g., revealing cryptic species). We sort DNA barcoding studies at three levels: clade scale (e.g., familial and/or generic taxa), community scale (e.g., biotic communities in nature reserves and permanent forest dynamics plots), and regional scale (e.g., biodiversity hotpots). We further list ten major research programs proposed by the International Barcode of Life, which are related to DNA barcoding approaches from the prospective of systematics and taxonomy, biodiversity conservation, evolutionary ecology and phylogenetics, and the construction of digital platforms. We appreciate the huge capability of barcoding technology in the field of biological sciences, and also realize the challenges of DNA barcoding utilizations in multidisciplinary studies and the essential to add more tests before the large-scale applications.
Biological invasions have caused tremendous ecological and socio-economic damages worldwide. Therefore, it is important to develop methods for their effective management. Biological invasion is a process of adaptive evolution in which hybridization and introgression play an important role in promoting invasive species by changing their invasiveness. Therefore, understanding how the genetic mechanisms of hybridization and introgression influence biological invasion will facilitate effective control of invasive species. The escape of transgenes with special functions into populations of wild relatives through hybridization and introgression may change the invasiveness and weediness of the wild relatives, causing undesired environmental problems. This paper introduces the role of hybridization and introgression in adaptive evolution and speciation, and discusses how an alien species can change its adaptability, competitive ability, and invasiveness in new habitats through introgressive hybridization. Hybridization and introgression can cause polyploid and homoploid evolution of plant species, thereby influencing the fitness of new species and promoting the formation of an invasive species in new habitats. At the same time, with the rapid development of transgenic technologies, transgenic crops are being extensively released into the environment for commercial production. Biological invasion is a complicated evolutionary and ecological process, and future research should investigate the roles of hybridization and introgression in biological invasions in the context of the myriad factors that influence the process.
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.
The phylogenetic conservatism of plant functional traits and its association with community structure are important topics in ecological research. Plant functional traits are simultaneously affected by their evolutionary background, local habitat conditions and large-scale climate. In this study we asked whether functional traits have a significant phylogenetic signal and significantly affect species abundance in a community. For this objective, we used data from a 24 ha Gutianshan forest plot, which included species abundance and six functional traits of 156 woody species: leaf nitrogen content, leaf phosphorus content, leaf area, wood density, specific leaf area and seed mass. We found that all functional traits showed significant phylogenetic signal, suggesting that all functional traits are significantly affected by their evolutionary history. We also found that species abundance was correlated with leaf nitrogen content, leaf phosphorus content, leaf area, woody density and specific leaf area except seed mass, suggesting that resource acquisition significantly affects species abundance distribution in a community, and that these functional traits impact community structure in different ways.
Sponsors
Biodiversity Committee, CAS
Botanical Society of China
Institute of Botany, CAS
Institute of Zoology, CAS
Institute of Microbiology, CAS
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