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Search Results: 1 - 10 of 27910 matches for " KeMing Ma "
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Disruption of Ant-Aphid Mutualism in Canopy Enhances the Abundance of Beetles on the Forest Floor
Shuang Zhang, Yuxin Zhang, Keming Ma
PLOS ONE , 2012, DOI: 10.1371/journal.pone.0035468
Abstract: Ant-aphid mutualism is known to play a key role in the structure of the arthropod community in the tree canopy, but its possible ecological effects for the forest floor are unknown. We hypothesized that aphids in the canopy can increase the abundance of ants on the forest floor, thus intensifying the impacts of ants on other arthropods on the forest floor. We tested this hypothesis in a deciduous temperate forest in Beijing, China. We excluded the aphid-tending ants Lasius fuliginosus from the canopy using plots of varying sizes, and monitored the change in the abundance of ants and other arthropods on the forest floor in the treated and control plots. We also surveyed the abundance of ants and other arthropods on the forest floor to explore the relationships between ants and other arthropods in the field. Through a three-year experimental study, we found that the exclusion of ants from the canopy significantly decreased the abundance of ants on the forest floor, but increased the abundance of beetles, although the effect was only significant in the large ant-exclusion plot (80*60 m). The field survey showed that the abundance of both beetles and spiders was negatively related to the abundance of ants. These results suggest that aphids located in the tree canopy have indirect negative effects on beetles by enhancing the ant abundance on the forest floor. Considering that most of the beetles in our study are important predators, the ant-aphid mutualism can have further trophic cascading effects on the forest floor food web.
Partitioning the effects of environmental and spatial heterogeneity on distribution of plant diversity in the Yellow River Estuary
Xiu Yuan,KeMing Ma,De Wang
Science China Life Sciences , 2012, DOI: 10.1007/s11427-012-4338-3
Abstract: For successful conservation and restoration of biodiversity, it is important to understand how diversity is regulated. In the ecological research community, a current topic of interest is how much of the variation in plant species richness and composition is explained by environmental variation (niche-based model), relative to spatial processes (neutral theory). The Yellow River Estuary (YRE) is a newly formed and fragile wetland ecosystem influenced by both the Yellow River and Bohai Bay. Here, we applied variance partitioning techniques to assess the relative effects of spatial and environmental variables on species richness and composition in the YRE. We also conducted a species indicator analysis to identify characteristic species for three subestuaries within the YRE. Partial redundancy analysis showed that the variations in species richness and composition were explained by both environmental and spatial factors. The majority of explained variation in species richness and composition was attributable to local environmental factors. Among the environmental variables, soil salinity made the greatest contribution to species abundance and composition. Soil salinity was the most important factor in the Diaokou subestuary, while soil moisture was the most important factor influencing species richness in the Qingshui and Chahe subestuaries. The combined effects of soil salinity and moisture determined species richness and composition in the wetlands. These results increase our understanding of the organization and assembly of estuarine plant communities.
The effect of land use structure on the distribution of soil nutrients in the hilly area of the Loess Plateau, China
Bojie Fu,Keming Ma,Huafeng Zhou,Liding Chen
Chinese Science Bulletin , 1999, DOI: 10.1007/BF02909714
Abstract: The irrational land use is one of the main reasons for the soil erosion and nutrienloss in the loess hilly area of China. In this project, 4 types of typical land use structure of sustain ment for about 15 years in the loess hill slope are selected to study the effect of land use structure on the distribution of soil nutrients. From hill bottom to hill top, the patterns of land use types are: grassland-slope farmland-forest, slope farmland-grassland-forest, terrace-grasslandforest and slope farmland-forest-grassland. By measuring the contents of the total N, total P, available N, available P and organic matter of soils, the results show that the land use structure types of slope farmland-grassland-forest and terrace-grassland-forest have a better capacity to maintain the soil nutrients.
Viewpoints on the study of economic thresholds of cotton bollworm
北京东灵山区景观类型空间邻接与分布规律

MA Keming,FU Bojie,
马克明
,傅伯杰

生态学报 , 2000,
Abstract: Landscapes are the spatial mosaic of patches.How to find spatial distribution regularity of landscape types in a complicated patch mosaics still remains as a challenge in landscape pattern analysis.The spatial neighboring properties of the landscape types in Donglingshan mountain region,Beijing,China was studied,the spatial distribution regularity of the landscapes types was found by using the classification method adapted from community ecology.The results showed that,the spatial properties of the landscape types were quite different.The main factor determining the spatial neighboring diversity of the landscape types was the number of neighboring types.The spatial distribution of the landscape types was clearly divided into 3 groups by using the adapted TWINSPAN classification:subalpine,middle mountain,and low mountain groups.They were obviously correlated with elevation,and influenced by human disturbance degree.
Economics in biological conservation
生物保护的经济学

Keming Ma,Xue Bai,
马克明
,白雪

生物多样性 , 2006,
Abstract: Research in biological conservation has developed from conservation biology into conservation ecology. As the influence of societal and economic factors on biological conservation become more and more broad and profound, it is time now to further develop the field of conservation economics. Establishing na-ture reserves is one of the most important approaches for in situ biodiversity conservation. Unfortunately, present nature reserve management is mainly focused on biological and ecological aspects, economic consid-erations are badly lacking, which has led to some unsuccessful conservation practices and threats to sustain-ability. On the basis of reviewing relevant progress in economic studies on biological conservation, a concept and framework of conservation economics is proposed to provide a new approach for biological conservation from economic perspectives. Conservation economics is a more active approach to preserving biodiversity and managing nature reserves, and it will help conservation management authorities with investment deci-sion-making.
Greenhouse gas emission inventory from energy consumption of Beijing based on input-output analysis
基于投入产出法的北京能源消耗温室气体排放清单分析

TONG Kangkang,MA Keming,
童抗抗
,马克明

环境科学学报 , 2012,
Abstract: As a result of great energy consumption, there are significant amount of greenhouse gases (GHG) emitted from cities. Recent studies focused on GHG mitigation in urban region. In this study, the amount of GHG emission in Beijing, including CH4 and N2O, was calculated based on input-output method. In 2007, the amount of GHG resulted from energy consumption was 35.3172 Mt CO2 equivalent, in which CO2, CH4 and N2O was 35.1440 Mt, 1734.32 t and 435.83 t, respectively. The industry sector was the biggest emitter, accounting for 98.96% of CO2, 88.48% of CH4, and 98.99% of N2O emissions. In final consumption sectors, emission from the government was responsible for 15% of the total emissions of the three kinds of GHG, which was much higher than those from rural and urban households. Emissions embodied in exports accounted for over 40% of GHG emissions in final demand sectors, over ten times that embodied in imports. This demonstrated that Beijing was an emission exporter. The average emission efficiency in Beijing was slightly higher than the average level of the whole country. It would be necessary to control emission efficiency through industry structure adjustment and energy consumption in order to mitigate GHG emissions in Beijing.
The effect of land use structure on the distribution of soil nutrients in the hilly area of the Loess Plateau, China

Bojie Fu,Keming Ma,Huafeng Zhou,Liding Chen,

科学通报(英文版) , 1999,
Abstract: The irrational land use is one of the main reasons for the soil erosion and nutrienloss in the loess hilly area of China. In this project, 4 types of typical land use structure of sustain ment for about 15 years in the loess hill slope are selected to study the effect of land use structure on the distribution of soil nutrients. From hill bottom to hill top, the patterns of land use types are: grassland-slope farmland-forest, slope farmland-grassland-forest, terrace-grasslandforest and slope farmland-forest-grassland. By measuring the contents of the total N, total P, available N, available P and organic matter of soils, the results show that the land use structure types of slope farmland-grassland-forest and terrace-grassland-forest have a better capacity to maintain the soil nutrients.
MEASURING LANDSCAPE DIVERSITY : AFFINITY ANALYSIS OF PATTERN DIVERSITY
景观多样性测度:格局多样性的亲和度分析

MA Keming,FU Bojie,ZHOU Huafeng,
马克明
,傅伯杰,周华峰

生态学报 , 1998,
Abstract: The paper introduced the principles and methods of Affinity Analysis in landscape pattern analysis,pointed out that affinity analysis could measure the relative positions of subunits and mosaic diversity.Mosaic diversity is a metric which combined the information in affinity analysis,is an efficient measure of compositional pattern diversity.A lower mosaic diversity means a simpler landscape structure.Using affinity analysis,the diversity and complexity of different landscape can be compared,the distances of communities to the whole landscape can be determined,and the difference degrees of similarities and affinities beteen communities can be disclosed.Therefore affinity analysis closely combined supplied landscape diversity and species diversity,a new tool for describing cross level and cross scale structures and functions of these two kinds of entities.
Explaining the abundance-distribution relationship of plant species with niche breadth and position in the Yellow River Delta
黄河三角洲植物生态位和生态幅对物种分布-多度关系的解释

YUAN Xiu,MA Keming,WANG De,
袁秀
,马克明,王德

生态学报 , 2011,
Abstract: Species abundance and distribution are often correlated, such that the positive abundance-distribution pattern means the widespread species tend to be abundant, and narrowly distributed species rare. Several hypotheses have been proposed to explain the positive relationship between abundance and distribution, but the mechanisms behind this pattern still remain poorly understood. Among these hypotheses, the niche breadth and the niche position (or habitat availability) hypothesis are the most investigated, since the niche-based model predicts that both distribution and abundance mirror the degree to which local environmental conditions meet the requirements of species. We used outlying mean index to measure the niche position and the niche breadth of each species in the 436 quadrats collected in the three estuaries of the Yellow River Delta. The distribution of each species was represented as the number of sites occupied. We tested the relationship between the distribution and abundance of plant species with a specific aim to examine if this relationship follows the mechanistic basis of the niche-based (niche breadth and niche position) hypothesis. We estimated the relationship using ordinary least-squares regressions. There was a significant positive relationship (R2a=0.75) between the distribution and abundance of the plant species. We found a significant positive relationship between the niche breadth and abundance, and the regional distribution. The niche breadth explained 19% of the variation in abundance but 42% of the variation in distribution. There was a significant negative relationship between the distribution and the niche position, but the relationship between the abundance and the niche position was not significant. The niche position explained 46% of the variation in distribution. These results suggest that some widely distributed species tend to be, on average, locally abundant, and have wider niche breadth and lower marginality of niche position with regard to the environmental factors than the species that have more restricted distributions. When the relationship was significant, both the niche position and the niche breadth explained less than half of the variation in abundance and distribution, this suggests that not only niche-based processes, but also other mechanisms are likely to act in concert in determining the relationship between distribution and abundance of the plant species. Although there was some unexplained variability around the relationship, the niche breadth was more consistently related to the positive abundance-distribution relationship than the niche position. The positive pattern generally exhibited by the abundance-distribution relationships, has consequences for several areas of applied ecology, including conservation, harvesting, biological invasions and biodiversity inventory.
The contents and methods of integrated ecosystem assessment (IEA)
生态系统综合评价的内容与方法

FU Bojie,LIU Shiliang,MA Keming,
傅伯杰
,刘世梁,马克明

生态学报 , 2001,
Abstract: Ecosystems provide many kinds of products and services to human society. However, we still know less about current conditions of ecosystem and their future trends though they have been greatly altered by us in the past centuries. It is urgent to make an integrated ecosystem assessment in supporting decision making for ecosystem management to realize sustainable development. The conceptual framework and assessment procedures of integrated ecosystem assessment were developed in this paper. Integrated ecosystem assessment (IEA) is the basis for ecosystem management, which mainly includes the analysis of important goods and services of ecosystem, the diagnosis of ecosystem health, the prediction of future trends of ecosystem, as well as the relevant economical and social analysis. Integrated ecosystem assessment should also be carried out from a point of view of broad temporal and spatial scales, because long term ecological processes often exist in the "invisible present" and ecosystems interact with each other at different scales, which is also a challenge in the establishment of assessment indexes. The services of ecosystem are critical to the functioning of the earth's life support system. However, they have not been paid much attention in policy decision because they are not fully accepted in commercial market or not adequately in terms of comparable with economic service and manufactured capital. Actually, they are useful in estimating the "incremental" or "marginal" value of ecosystem service. Ecosystem services can be catalogued into four levels according to their functions, and can be evaluated by using five methods. They are, (1) direct market value method, (2) indirect market value method, (3) conditional estimation value method, (4) production/cost method, and (5) actual market influence estimation value method. Actually, integrated ecosystem assessment is of practical importance mainly because it focuses much more on the trade offs among various goods and services, which is also the task of ecosystem management. Ecosystem health is a new concept in ecology, which can be interpreted as a certain condition of ecosystem. Ecosystem health is analogous to human health, and many researchers have proposed lots of sensitive ecosystem health indicators. Ecosystem health can be assessed from vigor, organization and resilience. Each aspect can be assessed by different methods and formulae. Ecosystem management is founded on the principles of preserving ecosystem integrity while maintaining sustainable benefit for human society. It is driven by explicit goals, executed by policies, protocols and practices, and need to be adjusted by monitoring and research based on our best understanding of the ecological interactions and processes necessary to sustain ecosystem composition, structure and function. Sustainability is its ultimate goal. The principles and methods of ecosystem management are introduced, and the elements and obstacles are also discussed
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