Evaluating the role of livelihood assets in suitable livelihood strategies: Protocol for anti-poverty policy in the Eastern Tibetan Plateau,China

Although numerous studies have been conducted on the relationship between livelihood assets and strategies, only a few quantitative studies exist on the topic for anti-poverty policies with regard to the Tibetan Plateau. This study investigated 357 households in the upper reaches of the Dadu River watershed in the Eastern Tibetan Plateau, China, using the participatory rural appraisal method. Then, applying a multinomial logistic regression model, we quantitatively analyzed the relationship between livelihood assets and livelihood strategies, the findings of which have implications for local agricultural policy interventions. The preliminary results indicate that of the four classifications of livelihood strategies used in this study, the main livelihood strategy is that of the non-farming-dependent household type (i.e., Type III in our study) that combines agricultural and non-farm activities or practices self-employment for wages. There are significant differences in the livelihood assets owned by households with different livelihood strategies. Human, natural, and financial assets have significant influences on livelihood strategies, and the choice of livelihood strategy varies by livelihood assets. Further, with improvements in household labor capacity and cash income per capita, the livelihood strategies of non-agricultural and non-farming households may shift away from agriculture, while an increase in farmland cultivated per capita, cash income per capita, and household labor capacity may encourage households to adopt agriculture-dependent livelihood strategies. These findings contribute to research on livelihood and related development strategies and anti-poverty policies in not only the Eastern Tibetan Plateau but also other regions with similar livelihood strategies.     

Why did heterospory evolve?

The primitive land plant life cycle featured the production of spores of unimodal size, a condition called homospory. The evolution of bimodal size distributions with small male spores and large female spores, known as heterospory, was an innovation that occurred repeatedly in the history of land plants. The importance of desiccation‐resistant spores for colonization of the land is well known, but the adaptive value of heterospory has never been well established. It was an addition to a sexual life cycle that already involved male and female gametes. Its role as a precursor to the evolution of seeds has received much attention, but this is an evolutionary consequence of heterospory that cannot explain the transition from homospory to heterospory (and the lack of evolutionary reversal from heterospory to homospory). Enforced outcrossing of gametophytes has often been mentioned in connection to heterospory, but we review the shortcomings of this argument as an explanation of the selective advantage of heterospory. Few alternative arguments concerning the selective forces favouring heterospory have been proposed, a paucity of attention that is surprising given the importance of this innovation in land plant evolution. In this review we highlight two ideas that may lead us to a better understanding of why heterospory evolved. First, models of optimal resource allocation – an approach that has been used for decades in evolutionary ecology to help understand parental investment and other life‐history patterns – suggest that an evolutionary increase in spore size could reach a threshold at which small spores yielding small, sperm‐producing gametophytes would return greater fitness per unit of resource investment than would large spores and bisexual gametophytes. With the advent of such microspores, megaspores would evolve under frequency‐dependent selection. This argument can account for the appearance of heterospory in the Devonian, when increasingly tall and complex vegetative communities presented competitive conditions that made large spore size advantageous. Second, heterospory is analogous in many ways to anisogamy. Indeed, heterospory is a kind of re‐invention of anisogamy within the context of a sporophyte‐dominant land plant life cycle. The evolution of anisogamy has been the subject of important theoretical and empirical investigation. Recent work in this area suggests that mate‐encounter dynamics set up selective forces that can drive the evolution of anisogamy. We suggest that similar dispersal and mating dynamics could have underlain spore size differentiation. The two approaches offer predictions that are consistent with currently available data but could be tested far more thoroughly. We hope to re‐establish attention on this neglected aspect of plant evolutionary biology and suggest some paths for empirical investigation.     

中国脉线蛉属二新种(脉翅目,褐蛉科)

记述中国脉线蛉属Neuronema 2新种,即条纹脉线蛉Neuronema striatum sp.nov.和梵净脉线蛉Neuronema fanjingshanum sp.nov..模式标本均保存在中国农业大学昆虫博物馆.     

Resolving the Conflicts Between Biodiversity Conservation and Socioeconomic Development in China: Fuzzy Clustering Approach

Resolving the conflicts between biodiversity conservation and socioeconomic development is a global pursuit for the long-run prospects of the human species. Based on Wenchuan County, a typical county in southwestern China, a group of 20 indicators quantifying regional biodiversity and socioeconomic development was established to classify and evaluate the county area spatially. A fuzzy c-means clustering (FCM) algorithm was used as the classification method. Three indices including BD, DL and DR characterizing the value of biodiversity, the level and rate of socioeconomic development of the delineated regions were formulated. The results indicated that Wenchuan County was optimally classified into 4 types of regions (region I to IV). The area percentages of the regions vary widely from 4.3 to 65.7%. The sequences of the regions on biodiversity, socioeconomic development level, and socioeconomic development rate were, respectively, IV > II > III > I, I > III > II > IV and III >I >II >IV. The spatial strategy on coordinating biodiversity conservation and regional development is to develop mainly from the east(I, II, III) and to conserve mainly in the west(IV). Eco-industry, such as eco-tourism and eco-agriculture, need to be emphasized in the process of regional development. The quantitative methods used here may have a wide applicability.     

浙江省生境质量时空演变与生态红线评估

生境质量是反映生物多样性状况与局地生态功能的重要指标,在高质量发展背景下研究区域生境质量的时空演变具有重要意义。以浙江省为研究区,基于InVEST模型、热点分析及地理探测器模型探究生境质量的时空演变与影响因素,并利用生境质量结果对浙江省生态红线开展了定量评估。结果表明:(1)2000-2015年,浙江省生境质量均值呈减速下降趋势,空间上形成了西北、西南、中东高和东北、中部低的分布格局;生境退化度呈现"中心-外围"的圈层辐射结构。(2)热点分析显示,生境质量与生境退化度在乡镇尺度上集聚特征相似、冷热点空间分布趋势相反。(3)地理探测分析发现,地形(高程、坡度)是影响浙江省生境质量的主要因素,植被因素(NPP、NDVI)的贡献度随时间推移逐渐增大;浙江省生境质量空间分异受到自然因子与社会经济因子的协同作用。(4)浙江省生态红线的生境质量整体较高且稳定,不同红线类型的生境质量存在差异;高生境质量区与生态红线的错位区域主要分布在浙西南、西北部山区,而北部、中部以及东部相对较少。基于此,对生态红线调整、区域生态功能区划提出对应的策略,以期提升浙江省生态空间管控。     

The genus Cahara Ghauri, 1978 of China (Hemiptera,Heteroptera, Pentatomidae,Halyini) with?descriptions of two new species

Cahara Ghauri from China with three species is reviewed here. Two of them, Cahara incisura sp. n. and Cahara nodula sp. n. are described here. Key to the three Chinese species, habitus photographs and illustrations of genitalia are also provided. All examined materials including the types of three species mentioned are deposited in the Institute of Entomology, Nankai University, Tianjin, China (NKUM).