福建寿宁县兽害猖獗的成因及对策初探

1998～2006年,以寿宁县为调查对象,运用机械抽样法调查样带69条,运用访问调查法调查猎户农户100余户,运用点面互换法调查全县范围内农田作物受害程度。结果表明,全县近半数的村,15%的耕地存在兽害,99%的兽害及其损失源于野猪的活动。分析表明,兽害的成因有种群爆发、物种灭绝和生态系统衰败诸多因素,而人为干扰是各种现象的起因。最后提出治理山区兽害的对策,尤其应加强生态系统恢复和自然保护区建设。     

甜槠群落主要种群空间分布格局对人为干扰的响应

研究了不同人为干扰强度对甜槠天然群落中主要种群甜槠和赤楠的分布格局的变化动态.结果表明,人为干扰会使甜槠种群的聚集性加强,而赤楠种群的聚集性降低.干扰强度对甜槠聚集性的影响随树龄的增大而逐渐减小,而对赤楠聚集性的影响则是随林龄增大呈现由小→大→小的规律.     

Fine roots refilling process in an artificial gap in a Picea mongolica forest

Picea mongolica is an endemic but endangered species in China. The spruce forest is only found in sandy forest-steppe ecotones. In this study, we examined the initial response of the quantity and refilling process of fine roots in an artificial canopy gap with a diameter of 36 m in a P. mongolica forest. Under the canopy, the fine root length densities of trees, shrubs and herbs were 2,622, 864 and 3,086 m·m–2, respectively. The fine root biomass of trees, shrubs and herbs were 148, 62 and 65 g·m–2, respect...     

火干扰与气候因子对兴安落叶松径向生长的影响

火干扰对森林生态系统的稳定具有重要影响。以1987年5月森林火灾后的漠河林区为研究对象,按照不同的林火强度设置样地,在不同强度火干扰样地内,分别采集兴安落叶松(Larix gmelinii(Rupr.) Kuzen)的树轮样芯,建立树木年轮的宽度年表,分析不同强度的火干扰及气候对兴安落叶松径向生长的影响。结果表明:(1)不同强度火干扰对落叶松径向生长影响程度不同,轻度火干扰样地落叶松生长存在胸径加速生长期,重度火干扰样地落叶松生长存在胸径减速生长期。(2)轻度火干扰样地落叶松年轮宽度与前一年7月份和当年7月份降水量呈显著正相关(P<0.05),与前一年9、11月份和当年9月份最高气温呈显著正相关(P<0.05);重度火干扰落叶松年轮宽度与前一年7月份和当年7月份最高气温呈显著负相关(P<0.05)。(3)不同强度的火干扰对年轮宽度和气候因子的相关性影响不同,重度火干扰样地落叶松年轮宽度与气候因子的相关关系在火干扰前后的变化比轻度火干扰更加明显;该地气温过度升高不利于重度火干扰后落叶松的恢复,而对轻度火干扰后落叶松的径向生长的影响不显著。     

Factors affecting fish assemblage structure during seasonal stream drying

Abstract –  We evaluated fish assemblage structure during stream drying in north west Arkansas in 2002 and 2003. We sampled fish with a seine and backpack electrofisher and measured habitat variables along transects. Linear regression models were selected a priori and ranked according to Akaike's Information Criterion. In 2002, total fish density was negatively related to pool area and maximum depth, and positively related to canopy openness and substrate diversity. Similarly, central stoneroller ( Campostoma anomalum , Rafinesque) and creek chub ( Semotilus atromaculatus , Mitchill) densities were negatively related to maximum pool depth. In 2003, fish species richness was positively related to pool area whereas total fish, central stoneroller, and creek chub densities were negatively related to maximum pool depth. In addition, total fish density was negatively related to substrate diversity. Results indicated that physical factors are important predictors of fish assemblage structure during stream drying. However, differences among response variables between years indicated that the magnitude of stream drying might be critical in intermittent streams.     

Status of aquatic and riparian biodiversity in artificial lake ecosystems with and without management for recreational fisheries: Implications for conservation

1. Humanity is facing a biodiversity crisis, with freshwater-associated biodiversity in a particularly dire state. Novel ecosystems created through human use of mineral resources, such as gravel pit lakes, can provide substitute habitats for the conservation of freshwater and riparian biodiversity. Many of these artificial ecosystems are subject to a high intensity of recreational use, however, which may limit their biodiversity potential.
2. The species richness of several taxa (plants, amphibians, dragonflies, damselflies, waterfowl, and songbirds) was assessed and a range of taxonomic biodiversity metrics were compared between gravel pit lakes managed for recreational fisheries (n = 16) and unmanaged reference lakes (n = 10), controlling for non-fishing-related environmental variation.
3. The average species richness of all the taxa examined was similar among lakes in both lake types and no substantial differences in species composition were found when examining the pooled species inventory. Similarly, there were no differences between lake types in the presence of rare species and in the Simpson diversity index across all of the taxa assessed.
4. Variation in species richness among lakes was correlated with woody habitat, lake morphology (surface area and steepness), and land use, but was not correlated with the presence of recreational fisheries. Thus, non-fishing-related environmental variables had stronger effects on local species presence than recreational fisheries management or the presence of recreational anglers.
5. Collectively, no evidence was found that anglers and recreational fisheries management constrain the development of aquatic and riparian biodiversity in gravel pit lakes in the study region; however, the conservation of species diversity in gravel pit lakes could benefit from an increasing reliance on habitat enhancement activities.

     

农用纸膜破损试验

为了解地膜替代品——农用纸膜在水田中应用过程中的破损情况,采用模拟试验的厅法,对造成纸膜破损的气液泡大小进行研究试验结果表明：和不考虑泥断不平度的情况下,能够引起纸膜破损的最小气泡直径为9cm,最小液泡直径为6cm。     

楚雄州2012～2014年6种猪繁殖障碍性疫病的血清流行病学调查

[目的]了解楚雄州猪繁殖障碍性疫病的流行情况.[方法]采用血清学方法调查了楚雄州2012～2014年6种猪繁殖障碍性疫病的感染情况.[结果]楚雄州猪圆环Ⅱ型病毒病总阳性率达到89.41％,猪伪狂犬病总阳性率达到47.00％,猪细小病毒病阳总性率达到47.46％,猪乙型脑炎病总阳性率达到49.39％,猪衣原体病总阳性率达到24.36％,猪弓形虫病总阳性率达到23.98％.[结论]6种繁殖障碍性疫病广泛存在于楚雄州,此调查结果为控制繁殖障碍性疫病的流行提供了一定的参考依据.     

毛竹种群空间格局及分株间关联性——重复空间点格局分析

随着空间调查数据的增多和有重复的空间格局试验设计的需要,重复空间点格局分析方法不断得到研究和应用。采用有重复的空间点格局分析方法研究了不同营林模式下毛竹种群的空间分布格局及其分株间的空间关联性。结果表明：I类经营模式下形成的毛竹种群空间格局呈现随机分布,II类和III类经营模式分别在1.6-2.2 m和0.4-2.6 m尺度上达到了均匀分布的显著水平,表现为随着经营干扰强度的增大,毛竹种群在小尺度（〈3 m）上趋向于均匀分布;在较大尺度（〉4 m）上,3种营林模式毛竹种群空间格局均表现为随机分布;母株与新分株的空间关联性在3种营林模式下较为一致的表现出小尺度上的正关联,并在III类经营模式下,0.6 m、0.8 m和2.2 m尺度上达到了正关联的显著水平,而在较大尺度上,3种营林模式母株与新分株空间格局均表现为无明显的关联性。     

清香木天然林物种多样性及稳定性对不同干扰强度的响应

选择清香木(Pistacia weinmannifolia)典型群落样地,划分为不同干扰类型。采用物种丰富度、Simpson指数(D)、Shannon-Wiener指教(H)和均匀度指数(E)等物种多样性指数及改进的M-Godron稳定性测定方法,对清香木天然种群的物种多样性和稳定性进行分析。结果表明:清香木群落乔木层和草本层物种多样性表现为干扰弱干扰强,而灌木层为干扰弱干扰强;在不同干扰强度下群落稳定性均靠近稳定状态,其相对的稳定性比较是干扰强干扰弱,表现出与群落物种多样性不同的趋势。