废弃物基水热炭改良对水稻产量及氮素吸收的影响

生物炭农田回用是实现农林废弃物资源化利用和碳封存的有效手段.近年来,水热碳化技术由于在炭产率、能耗及生产过程中的烟气排放等方面显著优于常规热解碳化技术而受到关注.为实现农林废弃物的资源化利用,明确水热炭农田应用对作物生产力的影响,本研究通过原状土柱模拟试验和表征分析,研究了4种不同类型改良水热炭对两种典型土壤的水稻产量和氮素吸收的影响及可能的驱动因素.结果表明,锯末水热炭和秸秆水热炭经物理或生物改良后,在两种类型土壤上均能够增加水稻产量和氮素吸收,减少氮素损失,且其效应不受水热炭添加量影响(5‰,15‰;质量分数).与对照相比,水热炭添加处理的产量和氮素吸收量分别提高9.2%～20.7%和7.7%～17.0%.高C/N比的锯末水热炭更有利于高肥力土壤水稻氮素吸收量的增加;而低肥力土壤由于限制性因子较多,受水热炭类型的影响较小.通过对水热炭的表征分析发现,其表面养分元素丰富;水洗或生物改良后其表面孔隙结构有较大改善,C元素相对含量明显降低,N和O元素相对含量明显增加,这对养分的固持/供应可能产生影响.因此,水热炭改良后孔隙结构的改变和N、O元素含量的增加可能是其施用后水稻产量和氮素吸收增...     

The importance of incorporating functional habitats into conservation planning for highly mobile species in dynamic systems

The distribution of mobile species in dynamic systems can vary greatly over time and space. Estimating their population size and geographic range can be problematic and affect the accuracy of conservation assessments. Scarce data on mobile species and the resources they need can also limit the type of analytical approaches available to derive such estimates. We quantified change in availability and use of key ecological resources required for breeding for a critically endangered nomadic habitat specialist, the Swift Parrot (Lathamus discolor). We compared estimates of occupied habitat derived from dynamic presence‐background (i.e., presence‐only data) climatic models with estimates derived from dynamic occupancy models that included a direct measure of food availability. We then compared estimates that incorporate fine‐resolution spatial data on the availability of key ecological resources (i.e., functional habitats) with more common approaches that focus on broader climatic suitability or vegetation cover (due to the absence of fine‐resolution data). The occupancy models produced significantly (P < 0.001) smaller (up to an order of magnitude) and more spatially discrete estimates of the total occupied area than climate‐based models. The spatial location and extent of the total area occupied with the occupancy models was highly variable between years (131 and 1498 km²). Estimates accounting for the area of functional habitats were significantly smaller (2–58% [SD 16]) than estimates based only on the total area occupied. An increase or decrease in the area of one functional habitat (foraging or nesting) did not necessarily correspond to an increase or decrease in the other. Thus, an increase in the extent of occupied area may not equate to improved habitat quality or function. We argue these patterns are typical for mobile resource specialists but often go unnoticed because of limited data over relevant spatial and temporal scales and lack of spatial data on the availability of key resources. Understanding changes in the relative availability of functional habitats is crucial to informing conservation planning and accurately assessing extinction risk for mobile resource specialists.     

Pollution,habitat loss,fishing, and climate change as critical threats to penguins

Cumulative human impacts across the world's oceans are considerable. We therefore examined a single model taxonomic group, the penguins (Spheniscidae), to explore how marine species and communities might be at risk of decline or extinction in the southern hemisphere. We sought to determine the most important threats to penguins and to suggest means to mitigate these threats. Our review has relevance to other taxonomic groups in the southern hemisphere and in northern latitudes, where human impacts are greater. Our review was based on an expert assessment and literature review of all 18 penguin species; 49 scientists contributed to the process. For each penguin species, we considered their range and distribution, population trends, and main anthropogenic threats over the past approximately 250 years. These threats were harvesting adults for oil, skin, and feathers and as bait for crab and rock lobster fisheries; harvesting of eggs; terrestrial habitat degradation; marine pollution; fisheries bycatch and resource competition; environmental variability and climate change; and toxic algal poisoning and disease. Habitat loss, pollution, and fishing, all factors humans can readily mitigate, remain the primary threats for penguin species. Their future resilience to further climate change impacts will almost certainly depend on addressing current threats to existing habitat degradation on land and at sea. We suggest protection of breeding habitat, linked to the designation of appropriately scaled marine reserves, including in the High Seas, will be critical for the future conservation of penguins. However, large‐scale conservation zones are not always practical or politically feasible and other ecosystem‐based management methods that include spatial zoning, bycatch mitigation, and robust harvest control must be developed to maintain marine biodiversity and ensure that ecosystem functioning is maintained across a variety of scales. Contaminación, Pérdida de Hábitat, Pesca y Cambio Climático como Amenazas Críticas para los Pingüinos     

Biomass‐based targets and the management of multispecies coral reef fisheries

The failure of fisheries management among multispecies coral reef fisheries is well documented and has dire implications for the 100 million people engaged in these small‐scale operations. Weak or missing management institutions, a lack of research capacity, and the complex nature of these ecosystems have heralded a call for ecosystem‐based management approaches. However, ecosystem‐based management of coral reef fisheries has proved challenging due to the multispecies nature of catches and the diversity of fish functional roles. We used data on fish communities collected from 233 individual sites in 9 western Indian Ocean countries to evaluate changes in the site's functional composition and associated life‐history characteristics along a large range of fish biomass. As biomass increased along this range, fish were larger and grew and matured more slowly while the abundance of scraping and predatory species increased. The greatest changes in functional composition occurred below relatively low standing stock biomass (<600 kg/ha); abundances of piscivores, apex predators, and scraping herbivores were low at very light levels of fishing. This suggests potential trade‐offs in ecosystem function and estimated yields for different management systems. Current fishing gear and area restrictions are not achieving conservation targets (proposed here as standing stock biomass of 1150 kg/ha) and result in losses of life history and ecological functions. Fish in reefs where destructive gears were restricted typically had very similar biomass and functions to young and low compliance closures. This indicates the potentially important role of fisheries restrictions in providing some gains in biomass and associated ecological functions when fully protected area enforcement potential is limited and likely to fail. Our results indicate that biomass alone can provide broad ecosystem‐based fisheries management targets that can be easily applied even where research capacity and information is limited. Of particular value, is our finding that current management tools may be used to reach key ecosystem‐based management targets, enabling ecosystem‐based management in many socioeconomic contexts.     

土地资源对珠三角地区人口增长的约束分析

改革开放以来，随着经济高速发展，大量外来人口涌入珠三角地区。1979─2012年间，珠三角地区的常住人口从1797.42万人增至5681.70万人。大规模的人口增长使得珠三角地区的资源供给压力增大，特别是土地资源。2010年珠三角地区已开发的建设用地面积为8867 km2，其中深圳、东莞等城市的建设用地规模已经接近其土地资源的适宜开发上限，土地资源对人口增长的约束作用也日趋显著。为了评判珠三角地区土地资源压力对人口增长的影响，利用Malthus模型和Logistic模型分别对该地区9个城市的人口变化进行拟合，结果表明，2组模型对2000年前各城市的人口变化均有较高的拟合精度且拟合结果与实际情况较为相近，主要是由于该地区早期发展阶段的资源压力对人口增长的约束作用较小。2000年以后不同城市的Logistic模型与Malthus模型对人口变化预测呈现出不同的趋势，主要与各城市的土地资源压力密切相关。根据2组模型模拟结果的差异和土地资源的压力，将9个城市分为3组。其中深圳、东莞为第一组，这2个城市的人口增速最快、土地资源压力最大，相应的Malthus模型的估计值分别在2003年、2005年超过了实际人口，且其后估计值与实际值的差距逐渐增大。依据Malthus模型2020年深圳、东莞的人口预测值分别为6469.58万人、2386.81万人，这大大超过了这2个城市的资源环境承载极限。这一结果说明在深圳、东莞的人口高速增长已经不可持续，Malthus模型已不能反映其未来人口的变化趋势。第二组包括广州、佛山、珠海和中山4个城市。这组城市的人口增速相对缓慢，Malthus模型的估计值与实际人口较为接近，但2010年以来这4个城市人口的增长呈放缓趋势，Malthus模型估计值逐渐偏大。第三组城市包括人口增速最慢的江门、惠州和肇庆3个城市。这组城市的人口?     

MISSOURI RIVER DEVELOPMENT POLICY AND RURAL COMMUNITY DEVELOPMENT1

ABSTRACT: Federal planners, in proposing the massive main stem Missouri River water developments in Montana and North Dakota, promised economic and social benefits to the local residents. Five main stem dams, Fort Peck, Garrison, Oahe, Big Bend and Fort Randall, were evaluated for community and rural development effectiveness. Thirty-seven development factors were examined and improvements noted. Only small differences were noted between areas with water developments and the control area. Further analysis revealed that water development benefits moved downstream and to existing urban areas. The Missouri River's rural areas and small communities were not developed significantly by the water projects. Several problems associated with water development policy were illustrated by the study. Cultural differences between planners and the population impacted were ignored. Second, the allocation of social costs was not considered and related to this, serious geographic maldistribution of benefits and costs resulted. The differences between pre-development promises and development performance was dramatic. While the large dams remain as landmarks to engineering prowess, the projects need to be evaluated for their success in meeting humanistic development objectives. Major redevelopment may be warranted by such an ex-post evaluation.     

巢湖水资源开发和水环境保护

巢湖是我国五大淡水湖之一,也是安徽省最大淡水湖,对安徽省的工农业生产和人民生活起着举足轻重的作用。本文分析了对巢湖水资源开发中产生的主要环境问题,并提出了在保护生态环境的前提下开发巢湖水资源的战略措施。     

农业资源开发规划优化与评估方法

本文把项目评估与农业资源开发规划模型的优化结合起来,用净现值法、益本比法和内部报酬率法进行项目评估,以净现值作为规划目标进行优化规划,并试用于泗阳县黄河故道滩区荒地资源开发的评估与规划,取得了显著的效果。     

湘中涟源煤盆地煤层气形成气藏的条件及其资源预测

湘中涟源煤盆地早石炭世测水组、晚二叠世龙潭组煤系是中国东南诸省境内最重要的煤系，具有较大的生气、储气能力。本文从煤系的构造热滨化、构造、沉积及煤层理深等方面论述了研究区测水组、龙潭组煤系中煤层气形成气藏的条件，并指出煤层气的开发远景区应该在煤盆地近南缘的诸含煤向斜南西扬起端，其中各主要区域性断裂交汇而成的断块是最重要的靶区。     

小凌河中华鳖自然保护区划分

随着人们消费观念的转变，中华鳖和野生鱼类价格的不断上涨，造成了掠夺性捕捞现象，其资源受到严重破坏。为保护中华鳖和野生鱼类资源特设立保护区，实现中华鳖物种恢复、繁衍，保护自然生态平衡。并创造一定的经济价值。