土壤多样性: 中国山东省基于1:100万比例尺的SOTER的实例研究

The diversity of soils derived from different parent materials and developed on different terrains inShandong Province, China, was analyzed with the theory of pedodiversity using a 1:1000000 scale soilsand terrain digital database (SOTER) of Shandong Province in a geographical information system (GIS)environment. Diversity index of soils derived from different parent materials followed the sequence of igneousrock ＞ sedimentary rock ＞ metamorphic rock ＞ unconsolidated material. Diversity index of soils developedon different terrains followed the sequence of plain ＞ medium-gradient mountain ＞ medium-gradient hill＞ valley floor ＞ medium-gradient escarpment zone ＞ depression ＞ high-gradient mountain. Abundancedistributions of these soil groups matched the logarithmic normal distributions.     

Recovery and dynamics of a primary tropical dry forest in Jamaica, 10 years after human disturbance

Changes in forest structure, the rate of recovery and stem turnover, 10 years after experimental cutting of a primary tropical dry forest in Jamaica, were determined by conducting a post-disturbance inventory of permanent sample plots in 2009. In April 1999, two plots within each of four blocks were assigned to two randomly allocated treatments (partially and clear cut) and a plot was assigned as a control (uncut). The treatment intensities were intended to mimic wood extraction for charcoal or timber production, a common form of anthropogenic disturbance in Caribbean dry forests. The application of the treatments significantly reduced the number of trees per diameter size-class, but after 10 years, the size-class distribution for the small size-classes was similar to pre-disturbance measurements. However, larger size-classes (?14 cm) in 2009 had fewer individuals when compared with the pre-disturbance size-class distribution. Ten years after cutting, tree height, basal area and tree density in partially cut plots had recovered by 92%, 81% and 94% and in clear cut plots by 78%, 35% and 78% respectively, in comparison with control plots. Although the biomass lost due to cutting and the original state of this forest have not fully recovered 10 years after disturbance, our results showed that coppicing allows the establishment of some semblance of a canopy and offers a rapid route to reclaim space. This newly established canopy also helps to ameliorate environmental conditions facilitating regeneration by seed, which would otherwise take years to occur due to the harsh conditions found in open areas. No new species or any species that could be described as pioneers were recorded and despite a shift in dominance, secondary succession did not occur. Therefore gap dynamics, often used to describe the process of regeneration in tropical rainforests, cannot be used to describe regeneration in this dry forest ecosystem.     

苜蓿土壤氮磷钾丰缺指标初步研究

选取综合肥力差异较大的5种农田土壤,安排全肥(适量N,P,K肥)、缺氮、缺磷、缺钾盆栽试验,依据第一年干草产量用养分丰缺法确定了种植新牧1号紫花苜蓿土壤的氮、磷、钾丰缺指标。盆栽试验结果表明:种植新牧1号紫花苜蓿,土壤碱解氮含量10～21mg·kg-1为缺、21～29mg·kg-1为中、29～40mg·kg-1为丰,大于40mg·kg-1为极丰;土壤速效磷含量3.3～7.7mg·kg-1为缺、7.7～11.3mg·kg-1为中、11.3～17.8mg·kg-1为丰,大于17.8mg·kg-1为极丰;土壤速效钾含量49～123mg·kg-1为缺、123～191mg·kg-1为中、191～338mg·kg-1为丰,大于338mg·kg-1为极丰。     

稻油轮作田杂草种子库组成及其垂直分布特征

杂草种子库是潜在的杂草群落，对杂草可持续治理具有重要意义。在稻油轮作田杂草种子库中共检测到28种杂草，主要隶属于禾本科、玄参科和菊科，种子库密度达224 550 seed/m2，其中约64％为冬季油菜田杂草种子。从杂草种子库中种子的垂直分布来看，土壤表层的种子密度较高，占整个种子库数量的63.88%，而中层和下层的种子密度较小，其垂直分布主要有3种类型。种子库中优势恶性杂草有菵草Beckmannia syzigachne、异型莎草Cyperus difformis、看麦娘Alopecurus aequalis、稻槎菜Lapsana apogonoides和日本看麦娘Alopecurus japonicus等，随着土层深度的增加，各土层的优势种组成也有差异。通过采取措施调控杂草种子库的规模，有望实现稻油轮作田杂草的可持续治理。     

白纹伊蚊生活习性及年数量消长

结果表明:伊蚊白天产卵量大于晚上,而且喜在黑色、粗糙的容器中(靠近水面处)产卵;盛水容器离地面距离越高,白纹伊蚊产卵量越少.在福州,幼虫出现在3月中旬,成虫始见于3月下旬,7至9月为发生高峰期;10月底至翌年3月上旬不见成虫活动.     

基于整合高通量绝对定量法的土壤微生物多样性分析

目前,常用的高通量测序技术只能得到微生物群落结构的物种种类和相对丰度,而整合高通量绝对定量法（iHAAQ）结合了高通量测序技术和qPCR技术,可以进一步计算得到微生物群落结构的绝对含量。相对丰度和绝对含量均是描述微生物群落结构的必备指标,其中相对丰度适合描述和评价微生物群落结构在单个样本内微生物之间的关系,而绝对含量更适于描述和评价微生物群落结构真实的数量变化以及在样本间微生物之间的关系。本研究基于发表的香蕉土传病害、再造沙地农业生态系统和微生物抑制剂作用3篇文献的高通量测序和qPCR数据,通过整合高通量绝对定量法获得3篇文献中古菌域、细菌域和真核生物域的真菌三类微生物群落结构的绝对含量数据,并进一步计算出这三类微生物整体（简称三域微生物）的绝对含量和相对丰度,从而对土壤微生物群落结构不同物种的相对丰度和绝对含量进行分析,旨在更加深入、准确地揭示土壤微生物群落及其生态功能。结果表明：（1）土壤中细菌的物种丰度和绝对含量高于古菌和真菌,在三域微生物中占据主导地位,缺乏绝对含量指标可能造成对微生物群落结构变化理解的偏差;（2）基于相对丰度和绝对含量数据分析,微生物群落结构α多样性指数结果相同,但β多样性指数结果不同;（3）在香蕉土传病害和再造沙地农业生态系统研究中,三域微生物的PCoA结果与细菌的结果较为相似,表明这两项研究中三域微生物群落结构主要受细菌的影响,但在微生物抑制剂的研究中未发现类似结果。整合高通量绝对定量法可以应用于所有同时进行高通量测序和qPCR测序的研究,在未来的土壤微生物群落结构研究中,采用高通量绝对定量法开展三域微生物群落的物种种类、相对丰度和绝对含量的整体评价,具有重要的生态学意义。     

高校招生就业数据分析与系统实现

本文分析了招生人数与相关数据的关系,研究了根据关联度的大小确定主要影响因素的计算机实现方法,从而可以进一步指导招生计划的编排。该系统对实际数据进行了分析,分析结果验证了系统功能具有良好的实用性。     

Empty forests: Large carnivore and prey abundance in Namdapha National Park, north-east India

Illegal hunting poses a dual threat to large carnivores through direct removal of individuals and by prey depletion. We conducted a camera-trapping survey in the Namdapha National Park, north-east India, conducted as part of a programme to evaluate carnivore and prey species abundance. Clouded leopard (Neofelis nebulosa) was the only large carnivore detected by camera-trapping. Indirect evidences indicated the presence of the wild dog (Cuon alpinus) and leopard (Panthera pardus), however, there was no evidence of tigers (Panthera tigris), suggesting their possible extinction from the lower elevation forests. Of the major ungulate prey species, sambar (Cervus unicolor) and wild pig (Sus scrofa) were the only large prey detected, while the Indian muntjac (Muntiacus muntjak) was the only small prey species detected. Relative abundances of all species were appreciably lower than estimates from other tropical forests in south-east Asia. We suspect that illegal hunting may be the cause for the low carnivore and prey species abundance. An ongoing community-based conservation programme presents an opportunity to reduce local people’s dependence on hunting by addressing their socio-economic needs and for using their skills and knowledge of the landscape for wildlife conservation. However, long-term wildlife monitoring is essential to assess the efficacy of the socio-economic interventions in bringing about wildlife recovery.     

The impacts of roads and other infrastructure on mammal and bird populations: A meta-analysis

Biodiversity is being lost at an increased rate as a result of human activities. One of the major threats to biodiversity is infrastructural development. We used meta-analyses to study the effects of infrastructure proximity on mammal and bird populations. Data were gathered from 49 studies on 234 mammal and bird species. The main response by mammals and birds in the vicinity of infrastructure was either avoidance or a reduced population density. The mean species abundance, relative to non-disturbed distances (MSA), was used as the effect size measure. The impact of infrastructure distance on MSA was studied using meta-analyses. Possible sources of heterogeneity in the results of the meta-analysis were explored with meta-regression.Mammal and bird population densities declined with their proximity to infrastructure. The effect of infrastructure on bird populations extended over distances up to about 1 km, and for mammal populations up to about 5 km. Mammals and birds seemed to avoid infrastructure in open areas over larger distances compared to forested areas, which could be related to the reduced visibility of the infrastructure in forested areas. We did not find a significant effect of traffic intensity on the MSA of birds. Species varied in their response to infrastructure. Raptors were found to be more abundant in the proximity of infrastructure whereas other bird taxa tended to avoid it. Abundances were affected at variable distances from infrastructure: within a few meters for small-sized mammals and up to several hundred meters for large-sized mammals.Our findings show the importance of minimizing infrastructure development for wildlife conservation in relatively undisturbed areas. By combining actual species distributions with the effect distance functions we developed, regions sensitive to infrastructure development may be identified. Additionally, the effect distance functions can be used in models in support of decision making on infrastructure planning.     

Gradients of abundance of fish across no‐take marine reserve boundaries: evidence from Philippine coral reefs

• 1. An abundance gradient from high inside to low outside a no‐take marine reserve may indicate net emigration of adult fish from the reserve (‘spillover’).
• 2. We examined spatial patterns of abundance of fish across two ～900 m long sections of coral reef slope at each of two small Philippine islands (Apo and Balicasag). One section sampled the entire length of a no‐take reserve and extended 200–400 m outside the two lateral reserve boundaries. The other section, without a reserve, was a control. The reserves had had 20 (Apo) and 15 (Balicasag) years of protection when sampled in 2002.
• 3. Significant spatial gradients of decreasing abundance of target fish occurred across only one (Apo Reserve northern boundary = ARNB) of four real reserve boundaries, and across none of the control ‘boundaries’. Abundance of non‐target fish did not decline significantly across reserve boundaries.
• 4. Abundance of target fish declined sharply 50 m outside the ARNB, but enhanced abundance extended 100–350 m beyond this boundary, depending on fish mobility.
• 5. Density of sedentary target fish declined 2–6 times faster than density of highly vagile and vagile target fish across the ARNB.
• 6. Habitat factors could not account for these ARNB results for target fish, but did influence abundance patterns of non‐target fish.
• 7. The lack of abundance gradients of target fish at Balicasag may reflect reduced fishing outside the reserve since it was established.
• 8. Apo Reserve had a gradient of abundance of target fish across at least one boundary, a result consistent with spillover.

Copyright © 2006 John Wiley & Sons, Ltd.