浅论沙湾县荒漠生态区荒漠植被的保护与开发利用

沙湾县是以农业生产力支柱产业的地处准噶尔盆地南缘的半干旱荒漠内陆区域,区域内荒漠植物被较脆弱,随着经济与人口的快速增长及农、林、牧业的大发展、如何保护县域内荒漠生态区荒漠植被,更好的开发和利用这种资源、将是一个十分重要的研究课题。     

应用遥感技术监测和评价太湖水质状况

利用遥感信息和有限的实地监测数据建立了太湖水质参数预测模型 ,该方法可以用于太湖水质污染的预测、分析和评价 ,能够较好地反映水质的空间分布特征 ,尤其适合于大范围水域的快速监测 .研究结果表明 ,利用单波段、多波段因子组合以及主成分分析等手段可以使遥感信息得到更充分的利用 ,从而使预测结果更加精确 .预测结果显示 ,太湖流域已经呈现了严重的富营养化趋势 ,且空间分布不均衡 .东太湖以及靠近无锡和苏州的湖体附近相对污染更为严重 .     

Urban expansion and its contribution to the regional carbon emissions: Using the model based on the population density distribution

The method is used for calculating regional urban area dynamics and the resulting carbon emissions (from the land-conversion) for the period of 1980 till 2050 for the eight world regions. This approach is based on the fact that the spatial distribution of population density is close to the two-parametric Γ-distribution [Kendall, M.G., Stuart, A., 1958. The Advanced Theory of Statistics, vol. 1.2. Academic Press, New York; Vaughn, R., 1987. Urban Spatial Traffic Patterns, Pion, London]. The developed model provides us with the scenario of urbanisation, based on which the regional and world dynamics of carbon emissions and export from cities, and the annual total urban carbon balance are estimated. According to our estimations, world annual emissions of carbon as a result of urbanisation increase up to 1.25 GtC in 2005 and begin to decrease afterwards. If we compare the emission maximum with the annual emission caused by deforestation, 1.36 GtC per year, then we can say that the role of urbanised territories (UT) in the global carbon balance is of a comparable magnitude. Regarding the world annual export of carbon from UT, we observe its monotonous growth by three times, reaching 505 MtC. The latter, is comparable to the amount of carbon transported by rivers into the ocean (196–537 MtC). The current model shows that urbanisation is inhibited in the interval 2020–2030, and by 2050 the growth of urbanised areas would almost stop. Hence, the total balance, being almost constant until 2000, then starts to decrease at an almost constant rate. By the end of the XXI century, the total carbon balance will be equal to zero, with the exchange flows fully balanced, and may even be negative, with the system beginning to take up carbon from the atmosphere, i.e., becomes a “sink”. The regional dynamics is somewhat more complex, i.e., some regions, like China, Asia and Pacific are being active sources of Carbon through the studied period, while others are changing from source to sink or continue to be neutral in respect the GCC.     

Effects of Detectability on Estimates of Geographic Range Size in Bignonieae

Abstract: Extinction risk has not been evaluated for 96% of all described plant species. Given that the Global Strategy for Plant Conservation proposes preliminary conservation assessments of all described plant species by 2010, herbarium specimens (i.e., primary occurrence data) are increasingly being used to infer threat components from estimates of geographic range size. Nevertheless, estimates of range size based on herbarium data may be inaccurate due to collection bias associated with interspecific variation in detectability. We used data on 377 species of Bignonieae to test the hypothesis that there is a positive relationship between detectability and estimates of geographic range size derived from herbarium specimens. This relationship is expected if the proportion of the true geographic range size of a species that is documented by herbarium specimens is given by the product of the true geographic range size and the detectability of the species, assuming no relationship between true geographic range size and detectability. We developed 4 measures of detectability that can be estimated from herbarium data and examined the relationship between detectability and 2 types of estimates of geographic range size: area of occupancy and extent of occurrence. Our results from regressing estimates of extent of occurrence and area of occupancy on detectability across genera provided no support for this hypothesis. The same was true for regressions of estimated extent of occurrence on detectability across species within genera. Nevertheless, regressions of estimated area of occupancy on detectability across species within genera provided partial support for our hypothesis. We considered 3 possible explanations for this mixed outcome: violation of the assumption of no relationship between true geographic range size and detectability; the relationships between estimated geographic range size and detectability may be an artifact of a negative relationship between estimated area of occupancy and the sampling variance of detectability; detectability may have had 2 opposite effects on estimated species range sizes: one determines the proportion of the true range of a species documented by herbarium specimens and the other determines the distribution of true range size for the species actually observed with herbarium data. Our findings should help improve understanding of the potential biases incurred with the use of herbarium data.     

Multiple paternity in the cooperatively breeding fish <Emphasis Type="Italic">Neolamprologus pulcher</Emphasis>

In cooperative breeders, mature males may compete for fertilizations. In this study, we measured the degree of multiple paternity in a natural population of a cooperatively breeding fish. Neolamprologus pulcher (Perciformes: Cichlidae) is a highly social cichlid endemic to Lake Tanganyika. We used highly variable microsatellite loci to survey 12 groups with an average number of 10.6 brood care helpers per group and a total of 43 offspring (mean 3.6 per brood). In 11 of 12 groups, all young were assigned to the dominant female. The dominant male sired all offspring in three groups, part of the offspring in four groups, and in five groups, he had no paternity at all. In total, 44.2% of young were not fathered by the current male territory owner. Multiple paternity was found in 5 of 12 broods (41.7 %), with 8 of 35 young (22.9 %) being sired by males other than the respective territory owners. This is an exceptionally high rate of extra-pair paternity among cooperatively breeding vertebrates. Neither helpers present in these territories during collection nor neighbouring males were unequivocally assigned to have sired these extra-pair young. However, behavioural observations suggest that male helpers may have produced these young before being expelled from the territory in response to this reproductive parasitism. We discuss these results in the light of reproductive skew theory, cooperative breeding in vertebrates and alternative reproductive tactics in fish.     

集约化蔬菜种植区地下水中反硝化细菌的分离鉴定

从研究我国典型集约化蔬菜种植区地下水中硝酸盐的来源和浓度人手,进行富集、培养、分离、纯化,筛选出一株具有反硝化作用的菌株,通过形态学、革兰氏染色结合16SrDNA序列同源性分析鉴定,其鉴定结果为农杆菌(Agrobacterium sp.).该研究为开展地下水硝酸盐污染的生物修复储备宝贵的菌种资源,为地下水中硝酸盐污染的原位微生物修复和相关污水的生物处理提供微牛物基础,对于经济、有效的解决地下水硝酸盐污染和水资源短缺的问题有着十分重要的意义.     

区域人均基本农田需求面积测算模型及应用——以江苏省为例

为估计一定区域内基本农田保护面积,论文在探讨基本农田涵义的基础上,提出了区域人均基本农田需求面积的计算模型。该模型综合考虑了城乡居民对农产品的消费、复种指数、粮食作物播种面积比例、单产水平以及城市化水平等因素。以江苏省为例,计算1985-2004年江苏省城乡居民人均粮食消耗总当量。在此基础上,计算1985-2004年江苏省人均基本农田需求面积以及估计2005-2020年江苏省人均基本农田需求面积。结果表明,1985-2004年之间,江苏省人均基本农田需求面积平均值为0.054hm₂,考虑在外饮食情况时,该值为0.059hm₂;2005-2020年之间江苏省人均基本农田需求面积平均值为0.057hm₂。     

鄱阳湖湿地重金属形态分布及植物富集研究

研究了鄱阳湖湿地土壤中Cu,Zn,Pb和Cd形态与植物富集的关系. 结果表明:鄱阳湖土壤中Cu,Pb和Zn主要以有机态和残渣态为主,水溶态和离子交换态等生物有效性态含量很少;而Cd则主要以水溶态和离子交换态等生物有效性态为主,因此Cd的生态危害较大. 相关分析和偏相关分析均显示:植物中重金属含量与其生存环境中重金属水溶态或离子交换态含量直接相关,这与理论上植物只能吸收重金属水溶态相符. 植物对重金属的富集能力表现出Zn＞Cu＞Cd＞Pb的趋势. 用重金属水溶态或离子交换态进行植物富集研究,更具有可比性和科学性.      

东湖沉积物中微生物量与碳、氮、磷的相关性

对武汉东湖3个采样点柱状沉积物中总氮、总磷、总有机碳及微生物量的垂向分布进行了测定,并对生源要素与微生物量之间垂向分布的相关性进行了研究.结果表明,东湖柱状沉积物中总有机碳与总氮之间存在明显的同步变化趋势,其含量随着沉积物深度的增加而不断降低,处于纳污区的1号点的各种营养盐含量均显著高于其它各点.沉积物中的有机质有着明显的双重来源,1号点含有较高的陆源有机质成分,而远离排污口部分的2号和3号点的有机质来源则以水生生物为主.微生物量在沉积物表层最高,随着沉积物深度的增加而不断下降.微生物量与有机质含量之间存在极显著的相关性,但是受有机质来源不同的影响,微生物量与总氮、总磷之间仅在远离排污口部分存在极显著相关性.     

长荡湖底泥污染特征及水体富营养化状况

根据长荡湖底泥和水体实测资料,分析了底泥的污染及营养物质释放特征,发现底泥释放再悬浮产生的污染负荷占到入湖污染负荷总量的比例分别是:高锰酸盐指数为16%,TN为25%,TP为21%,是引起近年来长荡湖水体富营养化加剧的重要因素,特别是湖西区和湖南区达到富营养水平,湖心区水体含氮磷浓度也较往年有明显增大。为控制长荡湖底泥污染及水体富营养化的加剧,提出了长荡湖水环境保护的相关对策措施。