三江平原湿地典型草甸小叶章群落物种多样性的季节动态

本研究以三江平原湿地典型草甸小叶章群落为研究对象,从物种丰富度、均匀度和物种多样性指数等方面探讨其季节动态规律.典型草甸小叶章群落物种丰富度在7月份最高,生态优势度指数季节动态变化呈“V”型;多样性信息指数季节动态变化呈单峰型,6月末7月初群落群落的物种多样性最高,种类之间个体分配的均匀性最大;均匀度指数季节动态变化呈线型.群落α多样性的测度指标的季节动态变化表现出一致性.     

有机肥对草甸草原植物群落及物种多样性的影响

[目的]施肥措施是一项维持草原生态系统养分平衡的有效管理方式。文章通过田间试验研究了不同有机肥施用量对草地植物群落的影响,为退化草地的恢复和改良提供参考和理论依据。[方法] 2014—2021年立足于呼伦贝尔羊草（Leymus chinensis）草甸草原连续多年的施肥控制试验样地,设置了4个长期施肥处理：不施肥处理（Y0）、低水平有机肥处理（Y1）、中水平有机肥处理（Y2）和高水平有机肥处理（Y3）,研究植物物种重要值、功能群和群落物种多样性,并分析在不同施肥处理下的相关性关系和交互作用。[结果]（1）随着施肥水平的升高羊草重要值呈抛物线函数变化趋势,且中度施有机肥处理下最高;有机肥添加后的群落以及优势种羊草植物特征数值显著高于不施肥处理;植物群落多样性指数均随着施肥水平的升高逐渐减小。（2）施有机肥处理的群落高度、密度、盖度以及地上生物量的响应比显著高于不施肥处理;植物群落物种多样性指数响应比随着施肥水平的升高而降低的趋势比较明显。（3）群落功能群分类与不同施肥水平之间的交互作用显著,禾本科、豆科和毛茛科植物的重要值在不施肥处理与施肥处理之间差异显著;禾本科的重要值与多样性指数之间...     

物种多样性与空间尺度的关系研究进展

物种多样性与空间尺度的关系是生物多样性研究中的重要问题,研究尺度与物种多样性之间的关系,探索物种多样性空间分布的内在机制,有助于理解群落的结构格局和构建过程,对探究物种共存或物种多样性的形成和维持机制具有重要意义,同时也为生物多样性的有效管理和保护提供科学依据。     

基于栅格的中国东北地形起伏度与人口、经济关系研究

基于1 km的栅格尺度,定量分析了中国东北地形起伏特征与人口、经济的关系。研究结果表明,东北地区地形起伏呈现四周高、中部低的空间分布格局,地形起伏度整体偏低;东北地区人口和经济空间分布存在较高的集聚性,经济空间的集聚性低于人口空间;随着地形起伏度升高,东北地区人口密度和经济密度整体上均呈现出下降趋势。东北地区84.39%的人口和86.81%的生产总值分布在地形起伏度不超过0.7的区域,面积占比为73.6%,存在明显的集聚效应。     

三江平原沼泽化草甸小叶章群落生物量季节动态规律

对三江平原沼泽化草甸小叶章群落生物量进行研究;结果表明,沼泽化草甸小叶章群落生物量季节动态呈抛物线型,生物量最大值出现在7月末,为326.00 g/m2;生物量累积生长量季节动态呈单峰型,最大积累量334.75 g/m2;生物量生长量、生物量绝对增长率和相对增长率季节动态都呈"Z"型,其最大值出现在7月末,分别为238.39 g/m2,7.95g/d,0.1825g/g.d。     

三江平原洪河自然保护区植物多样性研究Ⅰ水冬瓜-丛桦-小叶章沼泽化草甸

水冬瓜-丛桦-小叶章沼泽化草甸是三江平原洪河国家级自然保护区草甸植被的重要类型之一;组成植物62种．隶属于28科45属。其中温带分布属27个．占65．85％,以长白、大兴安岭植物区系成分为主;生活型谱以草本地面芽和地下芽植物占优势。     

皖南山区草地资源开发与畜牧业发展

皖南山区自然条件优越，草地资源丰富，然而目前皖南山区畜牧业生产相当落后，林牧矛盾和农牧矛盾比较突出，限制了山区农业经济以及全省国民经济的发展；通过对皖南山区草地资源和畜牧业现状的分析，讨论了皖南山区畜牧业方面存在的问题与不足，提出了合理开发利用山区草地资源、大力发展皖南畜牧业的战略措施、以促进山区草地资源合理开发利用和皖南畜牧业的发展、促进皖南山区”三农”问题的解决及经济、环境、社会可持续发展。     

The value of plant genetic diversity to resource-poor farmers in Nepal and Vietnam

Genetic resources for food and agriculture are the biological basis of world food and nutrition security; and they directly or indirectly support the livelihoods of over 2.5 billion people. Genetic diversity gives a species or a population the ability to adapt to changing environments. For resource-poor farmers, adaptive animal breeds, crop varieties and cultivars adapted to particular micro-niches, stresses or uses are the main resources available to maintain or increase production and provide a secure livelihood. The economic value of genetic diversity for productivity and yield traits is discussed in the literature. However, it is difficult to value many other aspects of agricultural biodiversity as these have both direct and indirect values in terms of qualitative traits such as food, nutrition and environmental uses that include adaptation to low input conditions, co-adaptive complexes, yield stability and the consequent reduction of risk, specific niche adaptation, and in meeting socio-cultural needs. Together, the direct and indirect values of genetic resources for resource-poor farmers are expressed in a range of options in the form of the crop varieties and species they use for managing changing environments.

The value of genetic diversity to resource-poor farmers is seldom captured by markets or addressed by the international research agenda. This paper presents lessons learned from our work over 5–10 years in the Asia and Pacific Ocean (APO) region on participatory crop improvement, home gardens and on-farm management of agricultural biodiversity. The lessons illustrate how farmers adapt genetic resources to suit local environmental conditions. The paper focuses on the value of genetic diversity of selected crop species to meet people's food and other needs. Genetic diversity valued by resource-poor farmers is often maintained, selected and exchanged by local social seed networks. Identification of such genetic resources and their custodians is important if international agricultural research is to contribute to the reduction of poverty. The paper highlights some good practices from case studies that illustrate how such genetic resources could be exploited by informal research and development strategies or participatory plant breeding or for marketing value-added products.     

The assessment of the impact of oil palm and rubber plantations on the biotic and abiotic properties of tropical peat swamp soil in Indonesia

Current intensification of agricultural activities in Indonesia has led to increased use of tropical peat swamp forests for agriculture. Ideally, peat swamp ecosystems should not be disturbed as they provide essential services such as soil erosion control, ecosystem stabilization and moderation of climate and energy fluxes as well as reducing carbon emission and conserving biodiversity. In this study, agricultural land from Giam Siak Kecil–Bukit Batu Biosphere Reserve in Indonesia was evaluated to assess the impact of oil palm (burning and without burning) and rubber (5–10 and >40 years old) plantations on soil properties through comparisons with soils from a natural forest (NF). Substantial changes in the physico-chemical properties of soils from both plantations were observed including significant reductions in soil organic matter (4–18%) and water holding capacity (22–53%), but an increase in bulk density (ρb) (0.08–0.17?g?cm^?3). A significant increase in bacterial biomass was also observed following conversion of the NF to plantation (p<0.05). However, the oil palm plantation (OPP) (without burning) showed reduced microbial activities and the lowest Shannon diversity values (2.90) compared to other samples. Community-level physiological profiling showed impaired community function only in soils from the OPP but higher CO₂ exchange rates in most plantation soils. Soils from the rubber plantation (RP) were less impaired in terms of their natural function and therefore RPs appeared to be more suitable for sustainable agricultural use than OPP.     

贵州省黎平县退耕还林政策实施效果与可持续性研究

我国的退耕还林工程是林业六大工程之一,也是我国西部大开发的重要内容。退耕还林工程实施效果如何以及能否持续关系到中西部乃至全国的社会、生态、经济可持续发展。本文选择了贵州省黎平县作为案例对我国退耕还林政策实施效果与可持续性进行研究。通过第一手资料得出结论并提出了该政策如何实现持续或顺利转换的建议。     

Landownership Distribution,Socio‐Economic Precariousness and Empowerment: The Role of Small Peasants in Maresme County (Catalonia,Spain) from 1850 to the 1950s

I present fresh data that show the leading role played by smallholder peasants in land‐use intensification, technical improvement and landscape transformation in Maresme County (province of Barcelona, Spain) between 1850 and the 1950s. As a reaction to their precarious situation, caused by an unequal landownership distribution (which is assessed by looking at the minimum‐income and maximum workable farm sizes), smallholders drove agrarian changes in this coastal Mediterranean area. The results of their individual efforts, and their collective action through social mobilization and cooperatives, entailed a socio‐economic and political improvement, especially in denser populated areas closer to markets, until the arrival of Franco's regime.