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Table of Content
    Volume 19 Issue 4
    20 July 2011

    Ammopiptanthus mongolicus is a leguminous plant distributed in Mongolia and Inner Mongolia, Ningxia and Gansu of China. Its upper later developing flowers within sequentially flowering inflorescences show male-biased sex allocation in Turpan Eremophytes Botanical Garden of the Chinese Academy of Sciences. Its major pollinators land first on the intermediate ?owers and finally fly away from the upper flowers. Xiaoli Ma et al. studied the relationship between sex allocation of A. mongolicus and the pollinators’ directionality within inflorescence and adaptative strategy to pollination environment (For details see pages 432–440 of this issue). (Photographed by Xiaoli Ma).

    A process-based theoretical framework for community ecology
    Biru Zhu, Dayong Zhang
    Biodiv Sci. 2011, 19 (4):  389-399.  doi:10.3724/SP.J.1003.2011.11060
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    Understanding what maintains species diversity in a community is a central challenge in community ecology. However, consistent answers to this very question are not yet available. This dilemma has led some ecologists to call community ecology “a mess” and to rethink whether it is appropriate for community ecology to move only unidirectionally from patterns to processes. A new and promising theoretical framework is proposed. According to this new framework, there are four basic processes possible in a community: selection, drift, speciation, and dispersal. The relative importance of these four processes varies among communities. All current theories can be readily incorporated into this framework, because they individually consider a subset of the four processes. In this study we give a brief introduction to this process-based theoretical framework and use it to analyze the processes underlying existing community theories relating to niche, local and regional interactions, and ecological drift. Niche theory only considers balancing selection, whereas theories of local and regional interactions emphasize the role of speciation and dispersal, besides selection. Theories incorporating ecological drift focus on drift, dispersal and speciation but discount selection. We are confident that this new framework provides new insights that will help to integrate existing community theories.

    Conservation forum
    Climate change issue in Convention on Biological Diversity: negotiations and focuses
    Jun Wu, Chengyi Zhang, Haigen Xu
    Biodiv Sci. 2011, 19 (4):  400-403.  doi:10.3724/SP.J.1003.2011.04040
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    Recently, the issue of biodiversity and climate change is becoming a focus of the Convention on Biological Diversity (CBD), and parties to the convention have carried out heavy multilateral negotiations on the issue. This paper reviews the background pertaining to biodiversity and climate change, discusses the disputes and standpoints of major parties, and highlights two opposing groups: the developed countries represented by the European Union (EU), and the mega-diversity developing countries represented by Brazil, Columbia and China. The main disputes of the negotiations include: (i) Expansion of the climate change concept: EU nations hope to expand consideration of climate change and integrate it into various issues within the CBD, and to promote synergy among three Rio Conventions (Convention on Biological Diversity, United Nations Framework Convention on Climate Change, and United Nations Convention to Combat Desertification). However, the developing countries are more leery of these tendencies. (ii) Geoengineering and ocean fertilization: EU suggests forbidding geoengineering and establishing a global management framework, whereas the developing countries suggest applying the “precautionary principle” to these issues. (iii) Reducing Emissions from Deforestation and Forest Degradation (REDD): EU urges development of “Biodiversity Safeguards” for REDD, while the developing countries oppose this proposal. We surmise that the main reason for these debates is that the developing countries are afraid of being restricted by the EU and related developed countries, and that these debates will become more fierce in the future. In the end, we proposes some strategies for debate resolution: (i) strengthen communication and coordination of relevant domestic agencies; (ii) summarize and propagandize successful practices and experiences in the area of climate change in China; and (iii) improve research on REDD mechanisms.

    Original Papers
    A model for designing nature reserves with minimal fragmentation using a primal-dual graph approach
    Yicheng Wang
    Biodiv Sci. 2011, 19 (4):  404-413.  doi:10.3724/SP.J.1003.2011.10020
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    Habitat fragmentation is one of the most important causes of biodiversity loss. In order to maximize a nature reserve’s effectiveness it is important to minimize habitat fragmentation during the design phase. However, due to economic or geographic constraints, it is often infeasible to acquire a large area of contiguous land for a reserve; designing a nature reserve consisting of several smaller components is often a more realistic choice. Selecting these smaller components with which to assemble a reserve with minimal fragmentation then becomes an important way to reduce fragmentation. However, reserve site selection models which incorporate spatial attributes may encounter computational difficulties. Williams (2002) presented a linear integer programming model based on primal and dual graph concepts to select contiguous sites. This paper modified this model to design a nature reserve which can protect a set of target species while incurring minimal fragmentation among selected sites. The modified model defines two variables for each site, and the difference in the value of these two variables represents the extent of fragmentation. Computational performance tests showed that the model can solve a minimal fragmentation reserve design problem involving 100 potential sites in a reasonable period of time. As an empirical application, the model was employed to design reserve networks for the endangered and threatened bird species of Illinois, USA. Several reserve networks with minimal fragmentation under different scenarios were designed. The computational efficiency of linear integer programming models needs more improvement for designing large-size optimal nature reserves. The practical use of these models requires complete and accurate data sets including species distribution, cost of site selection, etc.

    Geographic patterns of endemic seed plant genera diversity in China
    Shengbin Chen, Zhiyun Ouyang, Yu Fang, Zhenji Li
    Biodiv Sci. 2011, 19 (4):  414-423.  doi:10.3724/SP.J.1003.2011.10289
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    Endemism describes the phenomenon that the distribution of individual species/taxa is critically restricted to a specific region. Seed plant genera endemic to China (endemic genera) are those with their main geographic distribution range within the borders of China. The geographic patterns of endemic genera can not only guide conservation planning, but these organisms are also important biological resources. We gathered data of 173 localities on environmental and spatial factors, and regional seed plant genera richness (GRN), endemic genera richness (EGRN) and endemic genera ratio (EGR), which was calculated by dividing EGRN by GRN. Multiple regression and variance partitioning were used to examine how environmental and spatial variables affect GRN, EGRN, and EGR. Our results showed that: (1) EGRN and EGR had stronger spatial variability than GRN, with highest values (richness and ratio) in central China and lower near national borders and continental edges. GRN exhibited an evident latitudinal gradient. (2) EGRN and EGR were mainly determined by habitat heterogeneity and spatial factors. Regional theoretical EGR was constrained by its geographical location, and was further adjusted by habitat heterogeneity (topographical complexity) and climatic factors. Geographical patterns of GRN, on the other hand, were mainly determined by climatic conditions and habitat heterogeneity rather than spatial factors. (3) Seed plant genera endemic to China could be rather difficult to define, and probably reflected inadequate information on phylogenetic evolution of local flora. Further studies are needed to examine the variance explained by spatial factors through a phylogenetic lense. Finally, flaws in the definition and classification of seed plant genera endemic to China were discussed. Theoretically, genera endemic to China should not be defined according to the political borders. But, in practice, nearly all the lists of seed plant genera endemic to China proposed by several authors were based on the relationship between the geographic distribution of specific genus and national borders. Thus, we recommend that, the concept of seed plant genera endemic to China should be used carefully in both theoretical research and biodiversity conservation practices.

    Effects of disturbance, topography, and soil conditions on the distribution of invasive plants in Wenzhou
    Mo Gao, Renyong Hu, Xianxing Chen, Weicheng Li, Bingyang Ding
    Biodiv Sci. 2011, 19 (4):  424-431.  doi:10.3724/SP.J.1003.2011.08325
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    In order to understand factors regulating the distribution of invasive plants in Wenzhou, we used route-checking and fixed-plot sampling to evaluate the distribution of invasive species and associated agrotype, topographical and anthropological factors. Relationships between the distribution of invasive plants and the environmental factors were assessed using canonical correspondence analysis (CCA). Analysis of variance was used to test for differences in species composition and abundances of the invasive plants among different parts of the region, and to explore the major factors responsible for the differences. Our investigations showed: (1) 64 invasive plant species from 28 families and 51 genera were found in Wenzhou. More than 70% of those species were either annual or biennial dicotyledonous, and 68.8% of them were of American origin. (2) The number of invasive plant species differed among the 11 investigated counties of the region, among which Yueqing County had the highest number of species (51 spp.), followed by Cangnan (43 spp.), while Dongtou had the fewest (27 spp.). (3) The distribution of exotic invasive plants in Wenzhou was most affected by traffic frequency, the degree of settlement, and landform type. (4) The distribution of common eurychoric species was not affected strongly by any single environmental factor. The distribution of rare species with limited distributions, however, was affected significantly by both traffic frequency and landform; (5) Human activities played an important role during the initial stage of the invasion for the successfully invaded plants. Environmental factors were critical to the invading plants during the establishment stage of the invasion, while their biological characteristics had the major effect on their successful spread and on the extent of the damage they would cause in the areas they invaded.

    Variation in floral sex allocation, pollinator movement and reproductive success in Ammopiptanthus mongolicus inflorescences
    Xiaoli Ma, Dunyan Tan, Xinrong Li
    Biodiv Sci. 2011, 19 (4):  432-440.  doi:10.3724/SP.J.1003.2011.09032
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    The theory of sex allocation can be used to predict the optimal allocation of reproductive resources and considered as individual fitness between male and female function. Variations in resource allocation between sexes and among different positions in the flower inflorescence have great significance for understanding how choice of reproductive strategy affects reproductive success. Changes in floral sex allocation among different positions, pollinator movement and reproductive success within sequentially flowering inflorescences of Ammopiptanthus mongolicus were studied at the Turpan Eremophytes Botanical Garden of the Chinese Academy of Sciences. Our major results are as follows: (1) Floral longevity shortened significantly, stamen mass/(stamen mass + pistil mass), pollen number and pollen/ovule ratio all increased among positions along with the turn of intermediate earlier developing flowers→lower flowers→upper later developing flowers. Corolla diameter, corolla mass and nectar production, on the other hand, all diminished and ovule number showed no differences. Upper flowers showed male-biased sex allocation; (2) Within an inflorescence, Apis mellifera and Lasiglossum sp.1 landed first on the intermediate flowers, moved among different positions in the inflorescence, and finally flew away from the upper flower. Intermediate flowers had the highest first visiting rate but lowest last visiting rate while upper flowers had the lowest last visiting rate but highest first visiting rate; (3) During the two years of our study, the seed set rate and seed weight increased after supplying outcross pollen to the upper flowers; the fruit set rate, seed set rate and seed weight all increased significantly after simultaneously supplying outcross pollen to the upper flowers and removing the intermediate and lower flowers, and these measures did not differ between the two treatments. These results suggested that lower fruit set, seed set and seed weight of upper flowers under natural conditions can be attributed to the pollinators’ directionality within inflorescence and a lack of outcrossing pollen in upper flowers rather than resource limitation in A. mongolicus. Increasing investment in male functions on the upper fowers may be an adaptive strategy to sustain pollination success for the species.

    Diversity of ground-dwelling beetles within the southern Gurbantunggut Desert and its relationship with environmental factors
    Qiaozhe Lou, Yangcheng Xu, Jihong Ma, Zhaozhi Lü
    Biodiv Sci. 2011, 19 (4):  441-452.  doi:10.3724/SP.J.1003.2011.12287
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    To study the diversity of ground-dwelling beetle communities and their environmental relationships, and to understand their efficacy as habitat indicators and sensitivity to habitat perturbations, we used pitfall traps to investigate patterns of ground-dwelling beetle diversity along ecotones between the desert hinterland and desert-oasis ecotone along a desert edge in the southern Gurbantunggut Desert, including a disturbed habitat by desert highway protecting system. Our main results were as follows: (1) In total, we trapped 54,527 individuals of 81 species, belonging to 14 families, among which Tenebrionidae and Curculionidae were most dominant and accounted for 93.65% and 5.14% of abundance, respectively. Tenebrionidae was most abundant in the desert hinterland, while Curculionidae dominated ecotones both in terms of richness and abundance. All Platyope spp. showed a preference for aeolian sandy soil, while Adesmia aweiensis and Trigonoscelis sublaevigata sublaevigata showed a preference for alkaline desert soil. (2) Species richness, activity density, diversity, dominance, and evenness indices all showed difference among habitats (df = 32, P<0.05). (3) DCA (detrended correspondence analysis) ordinations of habitats based on ground-dwelling beetle communities or dominant groups showed that desert edge was the transitional area in our study area, and that communities on slopes were more similar to those in desert hinterland while those on interdunes were more similar to those in ecotones. (4) Factors including species richness and diversity, evenness and dominance indices were linearly correlated (P<0.05) with soil water content, nutrient content, total N, and total P content. Among them, the correlation with soil water content was the highest, and activity density showed the lowest and negative correlations with all environmental factors. (5) A significant decline in beetle activity density was detected within the highway protecting system (P<0.05); species richness, diversity index and evenness index all declined in the same area, although the differences were insignificant. The relative importance of main species also changed. Conclusions we can draw based on these results are: These communities show low richness, diversity, and evenness but high dominance and abundance. This becomes more pronounced as one moves from the desert-oasis ecotone to the desert hinterland. Desert ground-dwelling beetles showed certain habitat-indicative value at the family, genus and species levels. Soil type is likely the primary mechanism leading to the observed community ordination results. The negative relationship between activity density and soil water content might be a general rule of desert ground-dwelling beetle’s distribution at local scales. The desert highway protecting system within our study results has affected ground-dwelling beetle communities, and associated artificial plants (straw barrier, Haloxylon ammodendron and Calligonum sp.) might be the driving factor leading to these changes.

    Effects of habitat loss and fragmentation on species loss and colonization of insect communities in experimental alfalfa landscapes
    Zihua Zhao, Ying Wang, Dahan He, Rong Zhang, Mengmeng Zhu, Fenglin Dong
    Biodiv Sci. 2011, 19 (4):  453-462.  doi:10.3724/SP.J.1003.2011.10293
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    In agro-ecosystems, habitat loss and fragmentation may alter insect assemblages such as ladybug beetles and aphids, potentially affecting important ecological interactions. We used an experimental model system (EMS) with multiple micro-landscapes in which the habitat loss and habitat fragmentation impacts were distinguishable to test the following hypotheses: (1) Habitat removal results in short-term increases in population density in remaining habitat patches (crowding effect); (2) For the same total habitat area on a landscape, insect density will be higher in landscapes with more but smaller patches and more habitat edge than in less fragmented landscapes; (3) This positive effect of fragmentation on density is larger in landscapes with small inter-patch distances, and these last two effects on colonization should be reduced or disappear over time following habitat removal. This EMS included 18 fragmented and 18 clumped experimental plots. Alfalfa was cut to 1 m×1 m patches in fragmented plots (H=1) and retained the whole patches in continual plots (H=0). Habitat loss was designed to 90%, 80%, 70%, 50%, 20% and 0% respectively. Every plot was 3 times replicated and 0% of habitat loss was CK. Net sweeping, barber traps and clapper boards were used to investigate insect species in experimental alfalfa landscapes. 38 species were divided into 4 groups and diversity and abundance of every group were caculated and the relationship between diversity and habitat loss was analyzed. In our EMS, there was little support for the threshold phenomenon or for general effects of habitat loss and fragmentation, although this conclusion needs to be tempered by the limited duration of the experiment. We observed no threshold in species loss after habitat fragmentation and habitat loss in experimental alfalfa landscapes. The species number in fragmented habitat was higher than that in continual habitat under the same degree of habitat loss. Insect abundance was lower in micro-landscapes with 80-90% habitat loss than in CK. As for species, individuals in fragmented habitat were higher than that in continual habitat under the same degree of habitat loss. Insect diversity did not differ among variously treated micro-landscapes. It appears that insect colonization is low in micro-landscapes with 80-90% habitat loss; species richness, abundance and diversity were all significantly lower than that in CK, especially in fragmented habitats. Herbivorous species appear to colonize more rapidly than predatory species after habitat fragmentation and loss in experimental alfalfa landscapes. Our results did not support our first, but provided some support for the other two hypotheses. We suggest that fragmentation decreased the rate of immigration to patches, resulting in lower population densities in more fragmented landscapes. These results could be used to guide spatial and temporal aspects of the design of agricultural systems in order to enhance natural predator populations in agricultural landscapes and suppress pest population to the greatest extent.

    Fish species diversity and community pattern in coral reefs of the Xisha Islands, South China Sea
    Xuehui Wang, Feiyan Du, Zhaojin Lin, Dianrong Sun, Yongsong Qiu, Shuolin Huang
    Biodiv Sci. 2011, 19 (4):  463-469.  doi:10.3724/SP.J.1003.2011.07267
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    We assessed fish communities using bottom gillnet surveys in 7 coral reefs (Beijiao Reef, Huaguang Reef, Jinyin Island, Dongdao Island, Langhua Reef, Yuzhuo Reef and Yongxing Island) of the Xisha Islands in May, 2003 and analyzed species composition and diversity, dominant species, and community pattern using the software Primer. A total of 146 fish species belonging to 31 families and 10 orders were collected during the survey. Fishes in the coral reefs were dominated by the typical tropical species, including members of the families Scaridae, Chaetodontidae and Lutjanidae. According to the Index of Relative Importance (IRI), the six most dominant fish species were Myripristis murdjan, Lutjanus kasmira, Paracaesio sordidus, Caesio diagramma, Axinurus thynnoides and Hexanchus griseus, respectively. Shannon-Wiener diversity indices (H') ranged from 1.91 to 3.33 among reefs, with an average of 2.81. Overall, diversity indices for the Xisha Islands were higher than those found in the East China Sea, the Yellow Sea and the Bohai Sea, all of which are found at a higher latitude. The spatial pattern of fish communities was analyzed using hierarchical clustering and non-metric multidimensional scaling. Two major groups based on fish assemblages were indentified, with group I located in the Yongle Islands and Group II in the Xuande Islands. ANOSIM and RELATE tests showed significant differences (R=0.685, P=0.029<0.05) in fish assemblages between these groups and the community pattern were quite stable (R=0.958, P=0.003<0.01).

    The distribution and habitat use of Branchiostoma belcheri at the mouth of Jiaozhou Bay, Qingdao in Autumn
    Wei Yuan, Jun Wang, Qun Lin, Chenghua Wang, Jianqiang Sun
    Biodiv Sci. 2011, 19 (4):  470-475.  doi:10.3724/SP.J.1003.2011.06260
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    Branchiostoma belcheri is a second class protected animal species in China, and is distributed mainly in Jiaozhou Bay and adjacent areas. Based on an ecological survey in November, 2009, the distribution of the lancelet and its relationship with bottom sediments were studied. We found that Beisha waters may be the predominant habitat of lancelet in autumn. Most individuals within three year classes fit in a body size range of 30-40 mm. The abundance and biomass of lancelets in Beisha were 162 ind./m2 and 11.93 g/m2, respectively. No obvious length classes were observed in Nansha waters. The abundance and biomass of lancelets were 17.33 ind./m2 and 0.57 g/m2 in Nansha, respectively. We found that the sediment type in Beisha waters was gravel and sand while it was sand and silty sand in Nansha waters. Lancelets generally were found in areas with sandy sediment where the range of mean grain-size was very large with a water depth of 10-20 m. To cope with declining lancelet populations, an adequate reserve should be established in Beisha waters.

    Diversity and plant growth promoting activities of the cultivable rhizobacteria of Dongxiang wild rice (Oryza rufipogon)
    Fei Luo, Ya Wang, Qinggui Zeng, Riming Yan, Zhibin Zhang, Du Zhu
    Biodiv Sci. 2011, 19 (4):  476-484.  doi:10.3724/SP.J.1003.2011.09002
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    In order to understand the diversity of cultivable rhizobacteria associated with Dongxiang wild rice at different growth stages and to discover new species and strains of plant growth-promoting rhizobacteria (PGPR), we isolated 118 bacteria strains with different colony morphology using the dilution plate counting method and tested their plant growth promoting activities (PGPA) in May, August and November 2009. Phylogenetic analysis based on partial 16S rRNA sequences indicated that 118 strains clustered into 11 genera, and the dominant bacteria genera were Bacillus, Pantoea and Sphingomonas. The rhizobacteria displayed a high diversity with Shannon-Wiener indices of 2.037-2.741. PGPA analyses indicated that most strains displayed PGPR effects, including nitrogen-fixation, phosphorus-solubilization, IAA-production and siderophore-secretion, and that the dominant PGPR was Pantoea. Additionally, we found that the total amount and PGPA of cultivable rhizobacteria began to increase gradually at seedling stage of Dongxiang wild rice, and reached its peak at heading stage, then decreased at grain filling stage. Our results show that the diversity of bacterial communities in the rhizosphere soil of Dongxiang wild rice is abundant, and that the rich rhizobacteria may be a fascinating PGPR reservoir.

    Genetic diversity in rhizosphere soil microbes detected with SRAP markers
    Chunnan Li, Hairui Cui, Weibo Wang
    Biodiv Sci. 2011, 19 (4):  485-493.  doi:10.3724/SP.J.1003.2011.09232
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    We have attempted to use the SRAP (sequence-related amplified polymorphism) markers, a new molecular technology, to study genetic diversity in soil microbes. We sampled rhizosphere soil microbes from 20 plant species and employed 22 SRAP primer combinations. A total of 237 scorable fragments were identified, of which 221 (93.2%) were polymorphic loci. The average percentage of polymorphic loci (PPL), polymorphism information content (PIC), allele haplotype (Ah), and expected heterozygosity (He) for each primer combination were 93.78%, 0.94, 18.05 and 0.92, respectively. Our results revealed rich genetic diversity in rhizosphere soil microbes and the high ability of SRAP to resolve samples based on their genetic basis. Differences in genetic distance for rice rhizosphere microbes between two locations, and that among four different developmental stages were both significant at 0.01 level, but the difference was not significant between two varieties. Shannon diversity indices indicated that the genetic diversity of rhizosphere soil microbes was lowest in rice and highest in lettuce. The rhizosphere soil microbes from 20 plant species could be clustered into three groups at the 0.454 (GD) level based on UPGMA, in which the first group was from rice, while the second group was from celery planted in plastic green house, and the third group was from 18 other plant species cultivated in dry lands. Our results suggest that SRAP is an efficient method for analyzing the genetic diversity in rhizosphere soil microbes.

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