Dataset Information

Temporal and spatial variation of extreme temperatures in an agro-pastoral ecotone of northern China from 1960 to 2016.

ABSTRACT: The agro-pastoral ecotone of northern China is one of the areas most sensitive to global temperature change. To analyze the temporal and spatial trends of extreme temperature events in this area, we calculated the values of 16 extreme-temperature indices from 1960 to 2016 based on data from 45 national meteorological stations. We found that the coldest-temperature indices decreased significantly and the warmest-temperature indices increased significantly. The warming of night temperatures contributed more than warming of day temperatures to the overall warming trend. In addition, the warm-temperature indices appeared to be increasing since the late 1980s and early 1990s. Overall, though the four extremal indices showed an increasing trend, the rate of change in the minimum temperature was greater than that of the maximum temperature; thus, the minimum temperature contributed most strongly to the overall temperature increases. The growing season is being prolonged in higher-elevation areas, but vegetation maturation in lower-elevation areas has been accelerated by the high temperatures, potentially leading to a shorter growing season at low altitudes. However, the impacts of land-use changes caused by human activities on the temperature increases will require additional study.

SUBMITTER: Wang X

PROVIDER: S-EPMC5993746 | biostudies-literature | 2018 Jun

REPOSITORIES: biostudies-literature

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Temporal and spatial variation of extreme temperatures in an agro-pastoral ecotone of northern China from 1960 to 2016.

Wang Xuyang X Li Yuqiang Y Chen Yinping Y Lian Jie J Luo Yongqing Y Niu Yayi Y Gong Xiangwen X Yu Peidong P

Scientific reports 20180608 1

The agro-pastoral ecotone of northern China is one of the areas most sensitive to global temperature change. To analyze the temporal and spatial trends of extreme temperature events in this area, we calculated the values of 16 extreme-temperature indices from 1960 to 2016 based on data from 45 national meteorological stations. We found that the coldest-temperature indices decreased significantly and the warmest-temperature indices increased significantly. The warming of night temperatures contri ...[more]

PMID: 29884865

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Project description:Land use land cover (LULC) changes frequently in ecotones due to the large climate and soil gradients, and complex landscape composition and configuration. Accurate mapping of LULC changes in ecotones is of great importance for assessment of ecosystem functions/services and policy-decision support. Decadal or sub-decadal mapping of LULC provides scenarios for modeling biogeochemical processes and their feedbacks to climate, and evaluating effectiveness of land-use policies, e.g. forest conversion. However, it remains a great challenge to produce reliable LULC maps in moderate resolution and to evaluate their uncertainties over large areas with complex landscapes. In this study we developed a robust LULC classification system using multiple classifiers based on MODIS (Moderate Resolution Imaging Spectroradiometer) data and posterior data fusion. Not only does the system create LULC maps with high statistical accuracy, but also it provides pixel-level uncertainties that are essential for subsequent analyses and applications. We applied the classification system to the Agro-pasture transition band in northern China (APTBNC) to detect the decadal changes in LULC during 2003-2013 and evaluated the effectiveness of the implementation of major Key Forestry Programs (KFPs). In our study, the random forest (RF), support vector machine (SVM), and weighted k-nearest neighbors (WKNN) classifiers outperformed the artificial neural networks (ANN) and naive Bayes (NB) in terms of high classification accuracy and low sensitivity to training sample size. The Bayesian-average data fusion based on the results of RF, SVM, and WKNN achieved the 87.5% Kappa statistics, higher than any individual classifiers and the majority-vote integration. The pixel-level uncertainty map agreed with the traditional accuracy assessment. However, it conveys spatial variation of uncertainty. Specifically, it pinpoints the southwestern area of APTBNC has higher uncertainty than other part of the region, and the open shrubland is likely to be misclassified to the bare ground in some locations. Forests, closed shrublands, and grasslands in APTBNC expanded by 23%, 50%, and 9%, respectively, during 2003-2013. The expansion of these land cover types is compensated with the shrinkages in croplands (20%), bare ground (15%), and open shrublands (30%). The significant decline in agricultural lands is primarily attributed to the KFPs implemented in the end of last century and the nationwide urbanization in recent decade. The increased coverage of grass and woody plants would largely reduce soil erosion, improve mitigation of climate change, and enhance carbon sequestration in this region.

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Project description:BackgroundThe populations in Ethiopia have developed their indigenous knowledge to use, manage and conserve wild edible plants (WEPs). In the eastern part of Ethiopia, wild edible plants are used as a means of survival during times of food shortage and as dietary supplements. Documenting the traditional and cultural use of wild food plants is a vital step in obtaining baseline data for investigating nutritional values and possible side effects, preserving indigenous knowledge, and ultimately interesting in wild edible plant conservation. However, their significance, management and utilization have not been documented in Mieso District. Therefore, this study aimed to provide documentation of wild edible plant use associated with ethnobotanical knowledge in Mieso District, eastern Ethiopia.MethodsAn ethnobotanical study of wild edible plant species was conducted from March 2021 to May 2022. A total of 120 (72 males and 48 females) informants were selected using the snowball method. Data collection methods, including semistructured interviews, direct observation and field walks were used. Data were analysed using descriptive statistics, including independent sample t test and analysis of variance (ANOVA). We calculated use values (UVs) to analyse the relative cultural importance of each plant species.ResultsA total of 41 wild edible plant species belonging to 33 genera in 21 families were documented to be used as food sources both during times of food shortage and as dietary supplements. Family Malvaceae was best-represented with 6 species, followed by Fabaceae and Rhamnaceae (4 species each). The dominant growth form (habit) was shrubs (30 species), followed by trees (11 species). The most widely used plant parts were fruits (covering 39 species, 95%). The largest number (23 species) was collected from forest habitats only, followed by both village and forest habitats (8 species). The majority of wild edible plants (28 species or 68%) were consumed only during famine or in the time of food shortage followed by supplementing staple foods (9 species or 22%). Wild edible plants in Mieso are used for multiple other uses, including for fodder, fuel, medicine, construction, cosmetics and bee keeping. Twenty-three species were mentioned for fodder use, followed by fuel purpose (21 species) and medicinal value (13 species). The species that had the highest use values were Flacourtia indica (Burm.f.) Merr. (1.4), Carissa spinarum L. (1.1), Ziziphus spina-christi (L.) Desf. (0.6), Grewia villosa Willd. (0.5), Cordia monoica Roxb. (0.3) and Opuntia ficus-indica (L.) Mill. (L.) (0.2). Most WEPs were collected from March to May (Badheysa) (33 species). The highest mentioned wild edible plant sold in the market was F. indica (Burm.f.) Merr. mentioned by 20 informants, followed by Z. spina-christi (L.) Desf. (14).ConclusionThe people in Mieso use wild plants as supplementary food to cultivated crops, during famine, and many could be utilized for day-to-day human consumption. Some plants in the district provide cash income for local people. However, deforestation (54%), drought (22%) and agricultural expansion (12%) were the highest threats to wild plants in Mieso District. Hence, on-site and off-site conservation would help protect wild plant resources in Mieso, eastern Ethiopia.

Dataset Information

Temporal and spatial variation of extreme temperatures in an agro-pastoral ecotone of northern China from 1960 to 2016.

Publications

Temporal and spatial variation of extreme temperatures in an agro-pastoral ecotone of northern China from 1960 to 2016.

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