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Table of Content
    Volume 14 Issue 3
    20 May 2006

    Exotic invasive alligator weed (Alternanthera philoxeroides) can easily form dense monotypic mat in shallow water along shorelines. For details see pages 232–240 of this issue. (Photographed by Xiaoyun Pan)

      
    Identification of similar non-thermophilic Crenarchaeota in four Chinese and American pristine soils
    Haoxin Fan, Derek J. Fairley, Christopher Rensing, Ian L. Pepper, Gejiao Wang
    Biodiv Sci. 2006, 14 (3):  181-187.  doi:10.1360/biodiv.050267
    Abstract ( 3962 )   PDF (129KB) ( 3550 )   Save
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    Archaea have been discovered in non-extreme environments recently but not in Chinese pristine soils so far. This study was conducted to assess the presence of Archaea in two Asian pristine soils from Xinjiang and Guangxi of China and in two North American soils from southern Arizona region of the United States. Four 16S rDNA clone libraries were generated and 16S rDNAs related to 28 Crenarchaeota were identified in all four soils. All of the 16S rDNA sequences grouped closely with non-thermophilic terrestrial Crenarchaeotae, which is distinct from marine and freshwater crenarchaeotal clusters. Phylogenetic analysis indicated that the recovered 28 crenarchaeotal 16S rDNA sequences belong to two distinct clades that can be distinguished on the basis of either 16S rDNA sequence or G+C content. Our results demonstrate the presence of non-thermophilic Crenarchaeota in two Chinese and two American pristine soils for the first time in these regions, indicating that the range of these organisms is not restricted to extreme conditions. In addition, Clade 2 contains clones only from the American soils, indicating that the geographic locations and soil char-acteristics may influence the types of terrestrial crenarchaeotal populations.

    Karyotype diversity of Drosophila melanogaster species group in China
    Yuanhuai Qian, Wenyan Zhang, Qiuhong Deng, Jing Zhang, Qingtao Zeng, Yanling Liu, Shoutao Li
    Biodiv Sci. 2006, 14 (3):  188-205.  doi:10.1360/biodiv.050259
    Abstract ( 3743 )   PDF (736KB) ( 2686 )   Save
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    In the present study, 18 karyotypes in 40 species belonging to eight subgroups of Drosophila melanogaster species group in China were analyzed. Of the 18 karyotypes, six (A, A′′, C′′′, C′′′′, D′′ and F′) were novel. In the eight subgroups, F, F′, G and H were basic karyotypes for the Drosophila ananassae subgroup, A and A′′ for D. elegans subgroup, C for D. eugracilis subgroup, C′ for D. ficusphila subgroup, C and C′ for D. melanogaster subgroup, C, C′, C′′, D, D′, D′′, E, E′, E′′ and I for D. montium subgroup, C′′′ and C′′′′ for D. suzukii subgroup, and C, C′′′ and C′′′′ for D. takahashii subgroup. In D. lucipennis, the karyotype for female was 2n=8, while that for male was 2n=7, in which one of the chromosome Ⅳ was absent. In addition, B chromosomes were found in D. kikkawai, D. lini, D. ogumai, D. pseudoananassae, and D. triauraria. The karyotypes of six undescribed species were reported in this study, namely D. sp. like elegans, D. sp. like nyinyii, D. sp. like trapezifrons1, D. sp. like takahashii, D. sp. like trapezifrons2 and D. sp. like auraria. In this paper, the karyotype of a newly recorded species D. giriensis was also determined to be 2n=8, which be-longs to the C type. Our karyotype analysis reveals diversity in karyotypes of the Drosophila melanogaster species group in China, which will provide cytological evidence for further studies on genetics and evolution of Drosophila.

    The species composition and diversity of zooplankton in Nanji Islands National Nature Reserve
    Huanhong Ji, Shufeng Ye, Xing Liu, Junchao Hong
    Biodiv Sci. 2006, 14 (3):  206-215.  doi:10.1360/biodiv.050218
    Abstract ( 3701 )   PDF (547KB) ( 3562 )   Save
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    In order to elucidate the variation of species composition and diversity of zooplankton in Nanji Islands National Nature Reserve 14 years after establishment, we conducted investigations in four seasons from May 2004 to February 2005. A total of 69 species were identified, belonging to six phyla and 12 taxa. These species, with copepods accounting for 39.1%, could be classified into five ecotypes, of which the warm-water eurytopic group and warm-temperate offshore group were dominant. There were 15 dominant species, such as Calanus sinicus, Euchaeta concinna, and Sagitta enflata. Shannon-Wiener index (H′) was more than 2.0 in all seasons except winter, and it peaked in autumn (3.29). The species number presented no-table positive correlation with water temperature. Compared with data from 1990, the species number in spring and autumn had decreased, which may have resulted from the difference in water temperature. The seasonal change in zooplankton species composition was principally due to the fluctuation of Taiwan warm current and Jiangsu-Zhejiang coastal current in alternation.

    Butterfly diversity along a gradient of urbanization: Chongqing as a case study
    Hua Yan, Xingzhong Yuan, Wenping Liu, Heli Deng
    Biodiv Sci. 2006, 14 (3):  216-222.  doi:10.1360/biodiv.060034
    Abstract ( 5007 )   PDF (350KB) ( 4874 )   Save
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    To investigate the butterfly diversity in Chongqing Municipality, we selected five sampling sections along a gradient of urbanization from Shaping District to Beibei District, namely Shaping Park, Nanxikou, Huitoupo, Jigong Mountain, and Jinyun Mountain. A total of 4,802 butterfly individuals were collected, belonging to 11 families and 41 genera. Of these, the dominant species are Pieris canidia, P. rapae, and Pseudozizeeria maha, while common species are Graphium sarpedon, Eurema hecabe, Lethe syrcis, Polygonia caureum, Tongeia filicaudis, and Parnara guttata. The diversity indexes ranked in the following order:Jinyun Moun-tain>Huitoupo>Jigong Mountain>Nanxikou>Shaping Park. It is concluded that butterfly diversity, which is the highest in Jinyun Mountain and lowest in Shaping Park, increases with vegetation richness, vegetation coverage, and sunlight. Being significantly impacted by urbanization, butterfly diversity can serve as an effective indicator of urban environmental quality and change.

    Assessment of giant panda habitat in the Daxiangling Mountain Range, Sichuan, China
    Weihua Xu, Zhiyun Ouyang, Zeyin Jiang, Hua Zheng, Jianguo Liu
    Biodiv Sci. 2006, 14 (3):  223-231.  doi:10.1360/biodiv.050191
    Abstract ( 4160 )   PDF (326KB) ( 3467 )   Save
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    The status of giant panda habitat is related directly to the panda’s survival and breeding. Based on field surveys and using Geographic Information Systems (GIS) and Remote Sensing (RS), we studied the distribution, quality, spatial pattern, and conservation status of giant panda habitat in the Daxiangling Moun-tains, Sichuan. We selected altitude, slope, vegetation type, bamboo distribution, traffic, and residential area as evaluating criteria. Remote Sensing data showed that deciduous and conifer forest, which were closely as-sociated with giant panda habitat, occupied the largest area of 344,970 hm2 , accounting for 58.4% of the total study area, while shrub land occupied 18.4% and other vegetation types 23.2%. A comprehensive evaluation showed that the potential habitat in the Daxiangling Mountains was 118,749 hm2. However, much of the habitat was affected by exploitation of forest, mining, traffic, and agricultural activities, so that only 93,115 hm2 remained suitable. Moreover, the remaining habitat was separated into two fragments by roads, which caused failure of exchange between Yinghe Panda Group and Wawushan Panda Group. In total, the current nature reserve has protected only 28.0% of the entire habitat. For effective protection of giant pandas in this area, three aspects should be strengthened: (1) extending boundaries of the nature reserve to protect most of the giant panda habitat; (2) improving dispersal between giant panda populations through reforestation; and (3) at the altitudes of 1,800–2,700 m, controlling human activities to decrease impacts on giant panda habitat.

    Patterns of morphological variation of alligator weed (Alternanthera philoxeroides): from native to invasive regions
    Xiaoyun Pan, Hanzhao Liang, Alejandro Sosa, Yupeng Geng, Bo Li, Jiakuan Chen
    Biodiv Sci. 2006, 14 (3):  232-240.  doi:10.1360/biodiv.050223
    Abstract ( 4737 )   PDF (335KB) ( 3998 )   Save
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    The damage caused by biological invasions has traditionally been thought to result from alien species taking advantage of ecological differences between the native and introduced regions. In contrast, evidence is in-creasing that invasive plants can undergo rapid adaptive evolution during the process of range expansion. Using a common garden approach, we compared 19 morphological and anatomical traits of Alternanthera philoxeroides collected in native (Argentina) and invasive (China and USA) regions. The results show that native and invasive A. philoxeroides have become genetically differentiated. Populations from Argentina had significant morphological variation in nine traits, with heritability varying from 49% to 89%. The nine traits are stomatal density, stomatal index, diameter of stem, diameter of pith cavity, thickness of vascular cylinder, thickness of cortex, area ratio of vascular cylinder, area ratio of pith cavity, and leaf index. However, populations from introduced regions showed no significant variations in any of the 19 traits, indicating that the morphological differences within introduced regions might be based on phenotypic plasticity.Based on the result of PCA (primary component analysis), all five introduced populations and one population from Argentina (Santa Fé, 59°49′W, 29°16′S) can be clustered as one group, implying that the Santa Fé population may have similar genotypes with the lineage introduced to China. The existence of genetically differentiation of A. philoxeroides between native and introduced regions should be considered in any pro-grams that attempt management or utilization of this plant.

    Comparison of flowering phenology of two species of Ammopiptanthus (Fabaceae) under ex situ conservation in the Turpan Eremophytes Bo-tanical Garden, Xinjiang
    Xinrong Li, Dunyan Tan, Jiang Guo
    Biodiv Sci. 2006, 14 (3):  241-249.  doi:10.1360/biodiv.060024
    Abstract ( 3936 )   PDF (249KB) ( 3472 )   Save
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    The genus Ammopiptanthus (Fabaceae) , a typical evergreen broadleaf shrub of the northwestern deserts of China, comprises two species: A. mongolicus and A. nanus. Both are semi-endemic and relict species in China. In order to detect the differences between the two species in flowering phenology as well as factors influencing flowering, we investigated and compared flowering in the Turpan Eremophytes Botanical Garden in 2004 and 2005. (1) The two species are similar in terms of flowering frequency, flowering order of inflorescences, flowering amplitude curves, and the mean longevity of individual flowers, but differ consid-erably in the onset, the flowering duration of individuals, flower number per inflorescence, mean and fre-quency distribution of duration, and flowering amplitude. (2) At both individual and population levels, onset was earlier and duration was longer in A. mongolicus than in A. nanus . (3) A. mongolicus bore more flowers and had longer duration of flowering than A. nanus. There were significant differences both in flower number (F=17.51, P<0.01) and duration of inflorescences (F=14.08, P<0.01) between the two species. (4) The flow-ering of both species initiated from near the base spreading to the two ends, presenting a unimodal flowering amplitude, but A. nanus had a relatively higher flowering amplitude. (5) There were obvious differences in the frequency distribution of duration of inflorescences between the two species, but the mean longevities of individual flowers were similar (about seven days). (6) Pearson correlation analysis showed that the fruit number of an inflorescence was positively correlated with its flowering number per day(A. mongolicus, r=0.885, P<0.05; A. nanus, r = 0.827, P<0.01), while the flowering and fruit number of inflorescences per day had different correlations with onset, which may result from the different pollinators and genetic charac-ters of the species. The results showed that the similarity in flowering parameters in two species of Am-mopiptanthus may be explained by their phylogenetic relationships, while the differences, which are heredi-tary, may result from their evolutionary history in heterogeneous habitats. The differences in flower number and the duration of inflorescences in two years may be caused by temperature changes. These results can provide useful information for research on reproductive biology and conservation for the two Ammopiptan-thus species.

    Genetic diversity of wild Cymbidium goeringii (Orchidaceae) populations from Hubei based on ISSR analysis
    Li Gao, Bo Yang
    Biodiv Sci. 2006, 14 (3):  250-257.  doi:10.1360/biodiv.060015
    Abstract ( 4859 )   PDF (249KB) ( 4033 )   Save
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    Wild Cymbidium goeringii (Orchidaceae) plants in Hubei Province have become endangered due to over-harvesting and habitat fragmentation in recent years. The genetic diversity of 325 individuals from 11 populations in Hubei Province was investigated using inter-simple sequence repeat (ISSR) markers. As a re-sult, 127 bands were amplified by 11 informative and reliable primers, of which 112 were polymorphic loci. A relatively high level of genetic diversity was revealed: PPL=88.19%, He = 0.2628, Ho = 0.4037 (at species level); PPL = 63.06%,He = 0.1945, Ho = 0.2958 (at population level). A higher level of genetic differentia-tion was detected among populations with Nei's GST analysis and analysis of molecular variance (AMOVA; GST = 0.2440,FST = 0.2207). Some differentiation may result from habitat fragmentation and barriers to gene flow. UPGMA cluster analysis indicated that the five populations from Enshi region (BD, FBS, XE, MB, and LF) grouped together, whereas Dawu (DW) population clustered in an isolated clade. The Mantel test showed that genetic distance was positively correlated with geographical distance. Furthermore, the results showed that a mixed mating system was possibly the main factor influencing the genetic structure of this species. These results, combined with other information about C. goeringii, may provide a valuable basis for proposing conservation strategies. In situ conservation will be suitable for Laifeng (LF), Jingshan (JS), and Dawu (DW) populations with sufficient genetic diversity, while an ex situ strategy should be taken into consideration for Maoba and Xuanen populations, where only a few individuals are left.

    Community characteristics and interspecific association of the Songyang population of Isoetes sinensis
    Shengchao Zhu
    Biodiv Sci. 2006, 14 (3):  258-264.  doi:10.1360/biodiv.060014
    Abstract ( 3802 )   PDF (276KB) ( 3286 )   Save
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    Isoetes sinensis (Isoeteaceae), a critically endangered species in China, has declined rapidly in population size in recent years. Interspecific associations, which play an important role in ecosystem functioning, can reflect interspecific competition within communities. We investigated the habitat characteristics of the I. sinensis population in Songyang of Zhejiang Province using 1 m×1 m quadrats. Based on 2×2 contingency tables using test and association coefficients (AC), we analyzed the interspecific associations of I. sinensis with 27 common species frequently appearing in the community. The results showed that species abundance of the community was poor and the community was dominated by temperate elements. Isoetes sinensis can form the dominant population in a few microcoenses, but its density varied remarkably in different community types. The 2 values implied that I. sinensis had close relationship with seven species such as Neanotis hirsuta, Eclipta prostrata and Carex brevicuspis, but had no correlations with most species, with association coefficients (AC) ranging from –0.4 to 0.4. With poor ecological adaptability, I. sinensis is greatly affected by habitat and interspecific competition in the community. This result can provide information for design of an appropriate conservation strategy and restoration plan for I. sinensis.

    Economics in biological conservation
    Keming Ma, Xue Bai
    Biodiv Sci. 2006, 14 (3):  265-273.  doi:10.1360/biodiv.050137
    Abstract ( 4347 )   PDF (123KB) ( 3476 )   Save
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    Research in biological conservation has developed from conservation biology into conservation ecology. As the influence of societal and economic factors on biological conservation become more and more broad and profound, it is time now to further develop the field of conservation economics. Establishing nature reserves is one of the most important approaches for in situ biodiversity conservation. Unfortunately, present nature reserve management is mainly focused on biological and ecological aspects, economic considerations are badly lacking, which has led to some unsuccessful conservation practices and threats to sustainability. On the basis of reviewing relevant progress in economic studies on biological conservation, a concept and framework of conservation economics is proposed to provide a new approach for biological conservation from economic perspectives. Conservation economics is a more active approach to preserving biodiversity and managing nature reserves, and it will help conservation management authorities with investment deci-sion-making.


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