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Livelihood diversification of farmers and nomads of eastern transect in Tibetan Plateau

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Journal of Geographical Sciences 2010年第5期20卷 757-770页

作者： YAN Jianzhong WU Yingying ZHANG Yili ZHOU Shaobin College of Resources and Environment Southwest University Chongqing 400716 China Institute of Geographic Science and Natural Resources Research CAS Beijing 10010 China College of Politics and Social Sciences Chongqing Normal University Chongqing 400747 China

Livelihoods of farmers and nomads in Tibetan Plateau are severely affected by grassland and herbal resources degeneration. How to help them achieve livelihood diversi- fication is a key sustainable development issue. This paper examines livelihood assets, live- lihood diversification level and livelihood strategies of farmers and nomads in 3 regions of eastern transect in Tibetan Plateau. The results show that livelihood diversification is a popular strategy. From high mountain gorge region to mountain plateau region and plateau region, livelihood diversification level is reduced, and livelihood activities and proportion of extended livelihood also decrease. Livelihood assets and livelihood diversification level decrease with the increase of elevation, mainly shown in human assets and natural assets. Livelihood diversification level is highly correlative with livelihood assets, mainly shown in natural assets, human assets and social assets. Livelihood improvement strategies of farmers and nomads are still based on existing livelihood assets, mainly raising livestock and digging herbs, and less farmers and nomads consider off-farm employment or doing business. Nomads in plateau region should learn much from experiences of extended livelihoods of people in high mountain gorge region and mountain plateau region. Therefore, aids of governments should focus on relieving restricted factors of livelihood diversification and help them improve their abilities to build up extended type livelihoods.

关键词： Tibetan Plateau transect livelihood diversification livelihood assets

The Characteristics of Plant Communities Along East Eurasian Steppe transect

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Journal of Integrative Agriculture 2014年第6期13卷 1157-1164页

作者： HAN Wen-jun HOU Xiang-yang OLOKHNUUD Chun-liang Michael P Schellenberg Institute of Grassland Research Chinese Academy of Agricultural Sciences Semiarid Prairie Agricultural Research Center (SPARC) Agriculture and Agri-Food Canada

The East Eurasian Steppe transect （EEST） is the ifrst international transect across regions of middle and high latitudes in the eastern Eurasian steppe. The EEST is an ideal platform for researching the response of Eurasian temperate steppe to global change, because of its integrated gradients of temperature and human activities on a large-scale. In this study, basic characteristics of plant communities along the EEST across a latitudinal gradient was analyzed. According to the survey of 58 sampling sites, there are 140 species belonging to 34 families and 94 genera. Of particular note was the ifnding of Astragalus dalaiensis which has disappeared in the grasslands of China. On the whole, Gramineae plants are dominant with Liliaceae plants in the communities signiifcantly decreasing along the latitudinal gradient from south to north. The Shannon-Wiener index and biomass of communities all decreased along the latitudinal gradient with signiifcant negative linear regressions. The SDR2 （summed dominance ratio based on two factors） of dominant plants in the upper layers of communities, such as Stipa and Leymus chinensis, decreased along the latitudinal gradient from south to north. Especially, the SDR2 of L. chinensis decreased signiifcantly. The SDR2 of Cleistogenes squarrosa, Agropyron cristatum in the lower layers of communities and the indicator species for degradation were not affected. Potentilla acaulis was found mainly in the southern and northern areas. Stellera chamaejasme was found just in a few sites in the southern area of the EEST. In communities of Stipa grandis and Stipa krylovii, annual and biennial species are dominant. The ratio of annual and biennial species in the community is signiifcantly related to the latitudinal gradient. Perennial herbaceous plants and shrubs were not affected. According to the principal component analysis （PCA）, with the data from 58＆#215;140 dimensions, the ifrst and second components had the lowest proportion, thus indicating that the species compositions and community s

关键词： climate warming transect typical steppe species diversity summed dominance ratio

Distribution of C_4 plants along the Northeast China transect and its correlation to the environmental factors

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Chinese Science Bulletin 1999年第14期44卷 1316-1320页

作者： TANG HaipingOpen Research Laboratory of Environmental Changes and Natural Disaster of the Ministry of National Education, Beijing Normal University , Beijing 100875, Laboratory of Quantitative Vegetation Ecology , Institute of Botany , Chinese Academy of Sciences , Beijing 100093, China Open Research Laboratory of Environmental Changes and Natural Disaster of the Ministry of National Education Beijing Normal University Beijing Laboratory of Quantitative Vegetation Ecology Institute of Botany Chinese Academy of Sciences Beijing China

The distribution of C4 plants and the C4/C3 ratio along Northeast China transect （NECT） have been studied. A model to quantify their relation with environmental factors has been set up. The ratio of the number of C4 plants to that of C3 plants along NECT shows two low and two high trends from east to west, and their distribution is mainly decided by annual average temperature and precipitation.

关键词： Northeast China transect (NECT) distribution of C4 plants the C4/C3 ratio stepwise regression analysis.

Optimization of Coral Video transect Technique for Coral Reef Survey: Comparison with Intercept transect Technique

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Open Journal of Marine Science 2015年第4期5卷 379-397页

作者： Mohd Safuan Wee Hin Boo Hii Yi Siang Liew Hock Chark Zainudin Bachok Institute of Oceanography and Environment Universiti Malaysia Terengganu Kuala Terengganu Malaysia School of Fisheries and Aquaculture Sciences Universiti Malaysia Terengganu Kuala Terengganu Malaysia School of Marine Science and Environment Universiti Malaysia Terengganu Kuala Terengganu Malaysia

Variety in video sampling protocol for coral reef survey worldwide has prompted this study to?create an optimized protocol for Coral Video transect (CVT) technique for coral reef survey in Malaysia. The effect of different vertical distance of the camera above the substrate during video recording, number of frames and points analyzed as well as time spent during field and analysis were examined to determine an optimal protocol for CVT technique at different coral reef conditions in Malaysia’s water. Video recording taken at 0.5 m camera distance was selected as optimize vertical distance above the substrate as it can identify more benthic categories than 1.0 m with lesser time taken as well as frames extracted than 0.2 m. Respectively, 80% of total frames extracted from 20 m transect and analyzed with 50 points per frames were chosen as an optimized sample size for its ability to precisely estimate percent cover and accurately identify benthic categories.?This optimized protocol was then compared with Line Intercept transect (LIT) method. No clear difference in estimating percentage cover of major benthic categories between CVT and LIT method, but CVT recorded a significantly higher number of benthic categories with lesser time spent during field survey as compared to LIT method. This implied that the optimize CVT method can precisely estimate percent cover and accurately identify benthic categories in coral communities and are thus more suitable for scientific research and management purposes than LIT method. Other advantages of using this technique are by providing a permanent data that can be reassessed later on, lesser field time and wider survey area. Overall, this study showed that CVT technique is an acceptable alternative method of coral reef survey in Malaysia.

关键词： Coral Reef Survey Coral Video transect Optimize Protocol

Seasonal variation of carbon exchange of typical forest ecosystems along the eastern forest transect in China

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Science China Earth Sciences 2006年第S2期49卷 47-62页

作者： ZHANG Leiming, YU Guirui, SUN Xiaomin, WEN Xuefa, REN Chuanyou, SONG Xia, LIU Yunfen, GUAN Dexin, YAN Junhua & ZHANG Yiping Synthesis Center of Chinese Ecosystem Research Network (CERN), Institute of Geographic Sciences and Natural Resources Research, Chinese Academy of Sciences, Beijing 100101, China Institute of Applied Ecology, Chinese Academy of Sciences, Shenyang 110016, China South China Institute of Botany, Chinese Academy of Sciences, Guangzhou 510650, China Xishuangbanna Tropical Botanical Garden, Chinese Academy of Sciences, Kunming 650223, China Graduate University of Chinese Academy of Sciences, Beijing 100049, China

The long-term and continuous carbon fluxes of Changbaishan temperate mixed forest (CBS), Qianyanzhou subtropical evergreen coniferous forest (QYZ), Dinghushan subtropical evergreen mixed forest (DHS) and Xishuangbana tropical rainforest (XSBN) have been measured with eddy covariance techniques. In 2003, different responses of carbon exchange to the environment appeared across the four ecosystems. At CBS, the carbon exchange was mainly determined by radiation and temperature. 0℃and 10℃were two important temperature thresholds; the former determined the length of the growing season and the latter affected the magnitude of carbon exchange. The maximum net ecosystem exchange (NEE) of CBS occurred in early summer because maximum ecosystem photosynthesis (GPP) occurred earlier than maximum ecosystem respiration (Rθ). During summer, QYZ experienced severe drought and NEE decreased significantly mainly as a result of the depression of GPP. At DHS and XSBN, NEE was higher in the drought season than the wet season, especially the conversion between carbon sink and source occurring during the transition season at XSBN. During the wet season, increased fog and humid weather resulted from the plentiful rainfall, the ecosystem GPP was dispressed. The Q10 and annual respiration of XSBN were the highest among the four ecosystems, while the average daily respiration of CBS during the growing season was the highest. Annual NEE of CBS, QYZ, DHS and XSBN were 181.5, 360.9, 536.2 and -320.0 g·C·m-2·a-1, respectively. From CBS to DHS, the temperature and precipitation increased with the decrease in latitude. The ratio of WEE/Rθincreased with latitude, while Rθ/Gpp, ecosystem light use efficiency (LUE), precipitation use efficiency and average daily GPP decreased gradually. However, XSBN usually escaped such latitude trend probably because of the influence of the south-west monsoon climate which does not affect the other ecosystems. Long-term measurement and more research were necessary to understand the adaptation of forest ecosystems

关键词： forest transect carbon budget ecosystem photosynthesis ecosystem respiration China-FLUX eddy covaria

Effects of grazing intensity to water source on grassland condition, yield and nutritional content of selected grass species in Northwest Ethiopia

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Ecological Processes 2019年第1期8卷 149-161页

作者： Yaregal Melak Ayana Angassa Aster Abebe Department of Animal and Range Sciences Hawassa UniversityAwasaEthiopia Department of Range and Forest Resources Faculty of Natural ResourcesBotswana University of Agriculture and Natural ResourcesPrivate bag 0027GaboroneBotswana

Background:Savanna grasslands are globally important ecosystems consisting of one of the most extensive grazing lands with unique biodiversity.The objectives of the study were to assess the effect of grazing intensity on grassland ecosystem condition,herbaceous plant biomass production,and nutritional content of selected grass species.Methods:The study was conducted at Chagni Ranch,Northwest Ethiopia.Four transects to water source point at regular intervals of 20m between sampling plots along transects were used for data collection.The distance between the four transects was 200m in radius.Data were collected on grass composition,basal cover,litter cover,number of seedlings,and age distribution of dominant grasses(i.e.,young,medium,or old in terms of stage of maturity),soil condition in terms of soil compaction,and soil erosion linked to the effects of trampling by grazing animals along transects(hereafter referred to as transect)to water source point.The total sample size for grass species was 160 plots.The grassland ecosystem condition,herbaceous biomass,and grass nutritional content were used as response variables linked to transect from water source point.The effects of transect on grassland ecosystem condition scores and grass nutritional content were analyzed using the analysis of variance(ANOVA).Results:Grassland condition factors like grass composition,basal cover,litter cover,age distribution of dominant grasses,and soil condition were significantly(Ptransect to water source point than nearest transect.Out of the 28 identified herbaceous species,grasses accounted for 64.3%of the herbaceous community.Within grass species,about 55.6%were highly desirable in terms of palatability and grazing value(as most palatable species are susceptible to heavy grazing intensity).The results showed a significantly(Ptransect to water source point than nearest transect.The dry matter yield at the furthest transect(TD4)and third trans

关键词： Grassland condition Grass yield Nutritional content transect

Land use induced blurring of forest-grassland transition in north-west Himalaya-A case study using Moving Split Window boundary detection technique

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Journal of Mountain Science 2020年第12期17卷 3085-3096页

作者： Shevita PANDITA Harish Chander DUTT Ecological Engineering Laboratory Department of BotanyUniversity of JammuJammu-180006India

Transition zone or ecotone is a unique community sandwiched between two communities/ecosystems/biomes.These ecotones in Himalaya remained unexplored for many ecological aspects like biodiversity,phyto-sociology,boundary detection and even impact of change in land use pattern(anthropogenic activity).The most accepted and widespread technique called as Moving Split Window(MSW) technique is used for detection of vegetation and environmental boundaries at four different sites in the lesser stratum of north-west Himalaya.All the four sites were at different distances from the nearest human inhabited area.Anthropogenic activities like grazing,herb collection,wood collection etc.were common at proximal sites.Such activities have led to the change in land use pattern.In this study,we have tried to work out the impact of the change in land use pattern(human interference) on the vegetation and basic environmental parameters like soil pH,electrical conductivity and moisture on forestgrassland ecotone in north-west Himalaya.Data on mountain steepness was also collected and analyzed.The dissimilarity profile using the statistical tool Squared Euclidian Distance(SED) indicated that species turnover locations increase with the increase in distance of ecotones from human settlements.The ecotones at distant locations from human villages are characterized with blunt as well as sharp peaks for vegetation data,however,conditions are reverse in case of the proximal sites.The study also reveals that as the distance between the ecotone and human settlements increases,the complex conditions like multiple vegetation boundaries prevails on the transitions.In this regard,land use induced blurring of forest-grassland transition in north-west Himalaya is summed up in the study.

关键词： Ecotone Moving Split Window Squared Euclidean Distance transect Dissimilarity function Environment variables

Multi-scale spatial relationships between soil total nitrogen and influencing factors in a basin landscape based on multivariate empirical mode decomposition

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Journal of Arid Land 2019年第3期11卷 385-399页

作者： ZHU Hongfen CAO Yi JING Yaodong LIU Geng BI Rutian YANG Wude College of Resource and Environment Shanxi Agricultural UniversityTaigu 030801China National Experimental Teaching Demonstration Center for Agricultural Resources and Environment Shanxi Agricultural UniversityTaigu 030801China College of Agriculture Shanxi Agricultural UniversityTaigu 030801China Research Center for Scientific Development in Fenhe River Valley Taiyuan Normal UniversityJinzhong 030619China

The relationships between soil total nitrogen(STN)and influencing factors are scale-dependent.The objective of this study was to identify the multi-scale spatial relationships of STN with selected environmental factors(elevation,slope and topographic wetness index),intrinsic soil factors(soil bulk density,sand content,silt content,and clay content)and combined environmental factors(including the first two principal components(PC1 and PC2)of the Vis-NIR soil spectra)along three sampling transects located at the upstream,midstream and downstream of Taiyuan Basin on the Chinese Loess Plateau.We separated the multivariate data series of STN and influencing factors at each transect into six intrinsic mode functions(IMFs)and one residue by multivariate empirical mode decomposition(MEMD).Meanwhile,we obtained the predicted equations of STN based on MEMD by stepwise multiple linear regression(SMLR).The results indicated that the dominant scales of explained variance in STN were at scale 995 m for transect 1,at scales 956 and 8852 m for transect 2,and at scales 972,5716 and 12,317 m for transect 3.Multi-scale correlation coefficients between STN and influencing factors were less significant in transect 3 than in transects 1 and 2.The goodness of fit root mean square error(RMSE),normalized root mean square error(NRMSE),and coefficient of determination(R2)indicated that the prediction of STN at the sampling scale by summing all of the predicted IMFs and residue was more accurate than that by SMLR directly.Therefore,the multi-scale method of MEMD has a good potential in characterizing the multi-scale spatial relationships between STN and influencing factors at the basin landscape scale.

关键词： intrinsic mode function multivariate empirical mode decomposition multi-scale spatial relationship sampling transect soil total nitrogen Chinese Loess Plateau

Vocal behavior of Crested Guineafowl(Guttera edouardi) based on visual and sound playback surveys in the Umhlanga Lagoon Nature Reserve,Kwa Zulu-Natal province,South Africa

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Chinese Birds 2015年第3期6卷 132-139页

作者： Johann H.van Niekerk Department of Environmental Sciences College of Agriculture and Environmental SciencesUniversity of South Africa

Background:Generally speaking,playbacks were often ineffective to determine the group sizes of birds since mainly males from leks responded.This limitation has not been tested properly for flocking birds such as Crested Guineafowl(Guttera edouardi) with the view to use it as a counting method.The aims of the study reported in this paper were(1) to describe the cal s of Crested Guineafowl in a social context;(2) to interpret cal s in an evolutionary context;and(3) to demonstrate that playbacks can be used to locate and count Crested Guineafowl in smal isolated forests.Methods:The vocal behavior of Crested Guineafowl was observed during a survey conducted in the Umhlanga Lagoon Nature Reserve(Kwa Zulu-Natal,South Africa) from November 2010 to June 2012.transect line observations and sound playback methods were used.Results:The behavioral context and structure of cal s were described.The eight cal s described for Crested Guineafowl were produced mainly to unite flock members in the dense understory,where visibility was poor,and to repel intruders.When not disturbed,Crested Guineafowl were quiet and only made soft contact calls.Conclusions:The high rate of call back and the fact that flocks invariably approach the source of the call en masse,shows that field researchers are able to assess the population size of Crested Guineafowl with sound playbacks along a transect.The value of playbacks as a conservation tool is assessed.

关键词： Guttera edouardi Playback Calls Social behavior Flocking transect surveys