生境对无芒雀麦幼穗分化进程及生殖格局的影响

以乌苏1号无芒雀麦为材料,设置2个生长环境（荒漠绿洲区、高海拔地带）,通过观测幼穗分化进程及开花习性,探究生境对无芒雀麦幼穗分化及生殖格局的影响。结果表明,无芒雀麦幼穗分化从分蘖期开始至抽穗期结束,分为初生期、伸长期、结节期、小穗原基分化期、小花原基分化期、雌雄蕊原基分化期、雌雄蕊形成期和完穗期8个时期。幼穗分化是从生长锥顶端第1枝梗原基与小花原基开始分化,相同小枝梗上原基与小花原基均是自下逐渐向上发育;整穗是从顶部向下逐渐开花,下部枝梗开花时间小于上部枝梗;小穗上的小花由下向上逐步开花。与荒漠绿洲区相比,高海拔地带的无芒雀麦幼穗分化时间晚,周期缩短,穗部赤霉素（GA）、脱落酸（ABA）及叶片可溶性蛋白含量相对较高,细胞分裂素（CTK）含量和种子千粒重较低,但高海拔地带单穗成熟种子粒数与单位面积内种子产量高,更适合无芒雀麦种子生产。     

平潭主岛陆相区域景观格局动态变化分析

运用景观生态学的理论和方法,以平潭综合实验区主岛陆相区域为研究对象,利用1996年、2002年、2008年3个时相遥感影像为主要数据源,分析了与防护林关系密切的土地利用类型的景观格局指数,以期为平潭防护林乃至区域生态建设提供参考依据。结果表明:研究区景观格局呈现进一步破碎的趋势,与平潭经济社会发展的趋势一致;建筑用地、农用地等与林地关系密切的土地利用方式各项景观格局指数变化较强烈。最后从维护海岛生态安全的角度提出了4点建议。     

大亮子河国家森林公园典型植物群落物种组成与结构调查

采用典型取样的方法,对大亮子河国家森林公园内9个主要森林类型植被群落的物种多样性进行了调查。结果表明：9种典型森林植被类型的空间分布结构特征明显,从主要乔木树种的空间聚集分布上可以看出,不同物种对生境具有不同的要求,它们的分布与生境紧密关联,以典型森林群落类型的垂直分布结构规律性突出。     

从空间尺度论述陆生野生动物生境选择研究进展

指出了生境是动物生存和繁衍的重要场所,生境的质量及其可利用程度是决定动物种群生死存亡的关键因素。因此,研究动物的生境利用特点成为生物保护学研究的热点。综述了不同空间尺度上陆生野生动物生境选择研究的概况,以期对今后开展生境利用研究工作时在方法的选取方面提供借鉴和指导。     

基于BIOCLIM模型的元江干热河谷稀树灌木草丛空间分布研究

根据影响干热河谷稀树灌木草丛分布的温度、数字高程模型（DEM ）以及归一化植被指数（NDVI）三个因子,使用BIOCLIM模型模拟元江县干热河谷稀疏灌木草丛空间分布,实现了元江县干热河谷空间分布的可视化表达。结果表明：干热河谷分布主要集中于除元江县城外的河谷两侧,其中东部分布较为集中,而在南部地区分布较为分散。加之近年来人为活动的加剧,对元江河谷生态环境的变化也有一定影响,该模型很好地预测了未来元江县干热面积的分布情况,以期对生物多样性保护和植被恢复提供决策支持。     

桃蚜在辣椒上的空间分布及抽样技术研究

桃蚜作为世界范围内农作物主要害虫,在我国主要蔬菜种植区均有发生。因其繁殖能力强以及对蔬菜尤其是辣椒质量造成危害而成为重要防治对象。为了明确四川省成都主要辣椒种植区桃蚜空间分布格局,本试验运用2种回归方法和8个聚集度指标(K, C, CA, I, M*, m*/m, L*, L*/(1+m))对桃蚜盛发期种群的空间格局进行了研究；同时,通过Iwao回归法和Taylor幂法计算桃蚜种群理论抽样数,Iwao和kuno序贯抽样技术拟合桃蚜的序贯抽样模型。结果表明桃蚜种群呈聚集分布,聚集强度随种群密度的升高而增加,且个体间相互吸引,其聚集原因是由桃蚜习性与环境因素共同引起的,但8月下旬开始聚集原因主要有环境因素决定；通过种群密度与聚集度指标相关性分析表明,用平均拥挤度(m*/m)、负二项分布指标(K),久野指数(CA)及L*/(m+1)分析桃蚜空间分布型更具说服力；并利用空间格局参数确定了理论抽样数和序贯抽样模型。     

起垄沟播和常规平播下滴灌棉田土壤水盐的运移

为明确滴灌条件下植棉方式对土壤水盐运移的影响，采用田间调查与室内分析相结合的方法，在滨海重度盐碱地开展了起垄沟播和常规平播植棉方式下的水盐运移试验，调查了滴灌前后两种植棉方式不同点位及不同土壤深度的土壤水分、盐分和土壤溶液电导率等指标，分析不同植棉方式土壤水分、盐分和土壤溶液电导率的时空分布特征。结果表明：滴灌条件下起垄沟播的水分入渗深度和盐分淋洗深度均明显大于常规平播植棉方式，起垄沟播植棉膜下(0~20 cm)土壤溶液电导率明显低于常规平播植棉；滴灌对两种种植方式膜外土壤水分和盐分运移未产生明显影响。起垄沟播联合滴灌技术更有利于为棉花生长的水盐环境。研究结果可为盐碱地植棉提供理论参考和实践依据。     

Impacts of water resource planning on regional water consumption pattern: A case study in Dunhuang Oasis,China

Water resources are critical for the existence and development of oases in endorheic basins. Thus, to enable sustainable development, it is fundamentally important to understand how to allocate and use these resources in a reasonable way. We therefore simulated and analyzed changes in water consumption pattern within the Dunhuang Oasis of China under three scenarios using a system dynamic model that corresponds to different water consumption pattern. This was done to assess the impacts of regional water resource planning (comprehensive planning of the rational use of water resource and protection of ecosystem services in the Dunhuang Basin) on water consumption pattern within the Dunhuang Oasis. The first of these, Scenario 1, is a baseline in which the status quo is maintained, while Scenario 2 incorporates the comprehensive effects of agricultural water-saving irrigation measures with an inter-basin water diversion project, and Scenario 3 focuses on ecological rehabilitation. In the baseline Scenario 1, the total water consumption within the Dunhuang Oasis increased progressively while agricultural water consumption remained extremely high and threatened overall ecological security. In contrast, Scenario 2 would decrease agricultural water consumption by almost 5.30×10⁷ m³ following the implementation of water-saving practices. The additional water allocated from an inter-basin water diversion project would play an important role in alleviating ecological strain on the oasis. Finally, in Scenario 3, the total irrigated land must be decreased to 20.6×10³ hm² by 2025 assuming that water supply for ecosystem restoration would be at least 50% of the total consumption. Although water resource planning plays a very important role in alleviating the ecological water crisis within the oasis, it is necessary to consider the suitable scale of oasis with regard to current water consumption pattern.     

Bio‐physical models of marine environments reveal biases in the representation of protected areas

1. The significant shortfall in global marine protection targets is likely to continue to drive rapid growth in marine protected areas (MPAs). Systematic conservation planning to fill gaps in marine protection requires sufficient knowledge of both the distribution of biodiversity and the threats to species and ecosystems. Yet such data are lacking for much of the marine environment, creating significant challenges for planning effective marine protection.
2. In the absence of habitat mapping data, critical environmental variables associated with species' distributions can be used to model the spatial distribution of different environments. Although this approach has been used in some jurisdictions to assist MPA planners, the increased availability and resolution of spatial data now provide an opportunity to improve assessments of MPA representation.
3. Capitalizing on advances in spatial data, this study uses a range of biological and physical environmental attributes to model the distribution of Australian marine environments. Given many Australian MPAs were implemented without knowledge of the distribution of species and benthic habitats, this Bio‐physical model is used to assess MPA coverage and equality of protection for Australian marine environments.
4. Results of the Bio‐physical model revealed that Australian MPAs overrepresent warm, offshore waters (such as the Coral Sea) and underrepresent temperate environments. Furthermore, the distribution of protection in Australian MPAs is heavily skewed, with no‐take protection disproportionately targeting tropical environments, leaving major gaps in the protection of both temperate and nearshore habitats.
5. Without comprehensive habitat mapping, the representativeness and adequacy of an MPA system cannot be accurately evaluated, nor can the required expansion of MPAs be planned effectively. In the interim, the biological and physical attributes chosen for this model provide useful proxies to assist in efforts to better target current and future protection based on the most up‐to‐date knowledge.

     

Distribution and habitat characteristics of three sympatric cetacean species in the coastal waters of Matang,Perak, Peninsular Malaysia

1. Coastal cetaceans in Southeast Asia are poorly studied and are particularly vulnerable to anthropogenic threats, especially in intensive fishing grounds.
2. To investigate the distribution and habitat characteristics of cetaceans in the productive coastal waters of Matang, Perak, Malaysia, boat‐based line transect surveys were conducted between 2013 and 2016.
3. The Irrawaddy dolphin (Orcaella brevirostris) was most frequently encountered at 3.87 sightings per 100 km, followed by the Indo‐Pacific finless porpoise (Neophocaena phocaenoides) at 1.72 sightings per 100 km, and the Indo‐Pacific humpback dolphin (Sousa chinensis) at 0.66 sightings per 100 km.
4. The mean group size was largest for humpback dolphins (8.4 individuals), followed by Irrawaddy dolphins (6.4 individuals), and finless porpoises (2.8 individuals).
5. Humpback dolphins exhibited a clustered distribution concentrated mainly in shallow estuarine waters (<10 m deep and <5 km from river mouths), whereas Irrawaddy dolphins were more widely distributed in farther coastal waters (<15 m deep and <15 km from river mouths), and finless porpoises were mostly found farthest from the shore in coastal waters (10–25 m deep and >15 km from river mouths).
6. The spatial distribution of the three cetaceans overlapped minimally, and this is likely to reflect the distribution of preferred prey resources, species interactions, and their differential responses to anthropogenic activities and species dominance.
7. The results from our study serve as baseline information for future research, conservation, and habitat management of these vulnerable and endangered coastal cetaceans. Conservation actions are recommended for the Matang area.