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41.
42.
Orpheus M. Butler Mehran Rezaei Rashti 《Communications in Soil Science and Plant Analysis》2018,49(18):2231-2237
Optimised pre-analytical methods for measuring the chemical properties of soil macro-organisms are needed. We tested the effects of ethanol immersion, freezer storage, and drying method on the reliability of estimates of key stoichiometric elements (carbon [C], nitrogen [N], phosphorus [P]) and abundances of 13C and 15N in samples of crickets (Acheta domestica), cockroaches (Nauphoeta cinerea) and mealworms (larval Tenebrio molitor). Ethanol immersion tended to increase A. domestica C and N, and reduced A. domestica P, relative to the reference treatment (deep freezing and oven drying). For N and P these effects were only present after 28-day ethanol immersion. Nauphoeta cinerea and T. molitor samples were generally unaffected by storage treatments, while δ13C and δ15N were not affected by any storage treatment for any species. Thus, five days of ethanol immersion may be acceptable prior to elemental and stoichiometric analyses of hard-bodied soil invertebrates in comparative studies. 相似文献
43.
本文主要介绍了利用可视化开发语言、数据库技术和网络技术将历史的蠡湖鱼类种质资源数据进行整理、整合,最终通过网络发布,使蠡湖鱼类种质资源数据得到保存和共享。客户端录入平台和网站通过网络数据库被有机的结合在一起,更大程度的满足了数据维护和操作的需要。 相似文献
44.
Robert J. Rolls 《Biological conservation》2011,(1):339-349
Water resource development in coastal river catchments contributes to poor fish assemblage health due to the effects of barriers to migration and altered flow regimes. Impacts of migration barriers on fish assemblages depend primarily on the location of each barrier within the river network and migration needs of regional fish fauna. This study examined how temporal and spatial patterns in the distribution and composition of fish assemblages was associated with varying estuarine connectivity and migration barriers in higher altitude reaches in the eastern Hunter River catchment, temperate Australia. Species richness and abundances of diadromous species were expected to be greater in a tributary catchment with unrestricted connectivity to the Hunter River estuary when compared to a neighbouring tributary catchment with restricted connectivity. Six diadromous species were sampled only, or in greater abundances, in the unrestricted tributary when compared to the restricted tributary. As a consequence, assemblage composition in the restricted tributary was dominated by non-diadromous species. Greater abundances of the amphidromous Cox’s gudgeon (Gobiomorphus coxii) were sampled in the unrestricted tributary following their estuarine-freshwater upstream juvenile migration period when compared to the restricted tributary. Differences in the accumulations of migratory species immediately downstream of upland barriers between the two levels of estuary connectivity indicate that migration barriers in lowland reaches have significant effects throughout the entire catchment. Results of this study indicate that the location of each barrier to migration within river networks has varying consequences for catchment-scale connectivity loss and assessing the impacts of multiple barriers. Determining the effects and most appropriate management of migration barriers requires that all obstructions within a river network are recognised, as multiple barriers can have cumulative and interacting consequences for freshwater fish fauna, especially diadromous species. 相似文献
45.
陕北枣林土壤动物功能类群及其害虫生态调控 总被引:1,自引:0,他引:1
在陕北枣林研究区域内,以土壤动物为研究对象,采取野外调查取样、定点动态观测与室内鉴定分类的研究方法,选取了延安万花山、延川县、清涧县、佳县枣林4个样点7个样地,于2007年3月、6月、9月、11月,对土壤动物功能类群进行了初步研究。陕北枣林土壤动物可划分为植食性、捕食性、腐食性、枯食性、菌食性土壤、杂食性土壤动物6个功能类群,基于土壤动物功能类群与枣林病虫害生态调控的内在关系,建构陕北枣林害虫生态调控体系,为深入探讨土壤动物与枣林害虫生态调控的关系提供基础资料和理论依据。 相似文献
46.
采用石灰和有效微生物群(Effective Microoganisms,EM)处理改善了大兴安岭森林生态系统土壤微酸性环境和较低的微生物活性特征,于2003~2005年采用网袋分解法,揭示土壤动物群落多样性特征,为土壤动物生态地理研究和森林生态系统管理提供科学依据。研究表明,分解袋内土壤动物多样性对石灰和EM处理的响应表现出以下特征:(1)处理样地土壤动物个体数增加但类群数减少,其中螨类和弹尾类增加明显。(2)石灰和EM处理降低了土壤动物群落的多样性,对应分析表明石灰样地与其他样地有所差异。(3)各样地不同网孔分解袋中土壤动物类群数表现为大孔>中孔>小孔,而个体数基本上为中孔>大孔>小孔,是由于网袋内中小型土壤动物占优势而大型土壤动物数量较少引起的。(4)土壤动物类群数、个体数和多样性指数在针叶和阔叶网袋中响应特征不同,但彼此间没有显著差异。 相似文献
47.
陇东子午岭林区天蛾科昆虫区系研究 总被引:3,自引:0,他引:3
报道了陇东子午岭林区天蛾科昆虫的种类和区系组成。共获标本980号,经鉴定为42种,隶属于24属5亚科,其中甘肃省新记录10种。区系分析表明,古北界的种类15种,占总种数的35.7%;东洋界的种类5种,占总种数的11.9%;古北、东洋两界共有的22种,占总种数的52.4%。显然,古北、东洋两界共有的种类占优势。 相似文献
48.
永康市有两硒类20种,隶属2目6科8属。其中蝾螈目2种,蛙形目18种,占浙江省已知属的50.00%,种的41.86%。 相似文献
49.
50.
Results of several long-term studies of non-woody litter decomposition in forests indicate that we need to rethink why and how we measure rates of litter decomposition. Effects on litter decomposition rates were postulated to explain some of the nutritional effects of factors such as tree species, forest harvesting and fertilization. However, the accumulated experimental evidence indicates that litter decomposition rates do not mediate these responses. Many studies have reported litter mass loss becoming extremely slow at values considerably below 100%, indicating that early decay rates may not accurately foreshadow the entire decay process. Exclusion of soil faunal activities from current measurements of decomposition rates seriously reduces the likelihood that we are properly modeling decomposition. Finally, the use of regression and correlation analyses to determine which climate or initial litter quality factors control decay rate has led to many unwarranted and potentially misleading conclusions. These concerns are illustrated with examples from a suite of litter decomposition studies in British Columbia, Canada. Insights into nutrient cycling and carbon storage in ecosystems are more likely to arise from measuring the mass and nutrient content of annual litter input and determining the maximum decomposition limit and nutrient content at that stage, than by measuring early rates of decay. Improved predictions of relative decay rates of plant litters are likely to arise from a holistic approach based on plant life attributes rather than correlations based on individual initial litter chemistry parameters. Finally, a better understanding of the fate of faecal material of soil fauna is necessary before we can accurately predict and model litter decomposition. 相似文献