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41.
The Mongolian Plateau (MP) steppe is one of the largest steppe environments in the world. To monitor the terrestrial vegetation dynamics on the MP and to ascertain what the driving forces, this study examined the vegetation dynamics in Republic of Mongolia (M) and the Inner Mongolia Autonomous Region (IM) of China from the period 1982 to 2011, based on the satellite-derived GIMMS NDVI3g (Normalized Difference Vegetation Index) data across three biomes (desert, grassland and forest). The results are as followed: (1) Vegetation coverage in IM was generally greater than that in M. Before 2002, time series of NDVI over the MP increased at an average rate of 0.05% yr−1. Additionally, after 2002, the NDVI increased at a rate of 0.21% yr−1. From 1982 to 2011, the area of IM and M with positive anomalies in the NDVI increased at a separate rate of 1.82% yr−1 and 1.76% yr−1, respectively. (2) At the biome scale, the inter-annual forest NDVI variation in IM and desert NDVI for the entire MP had a significant increasing trend (0.06% yr−1 and 0.04% yr−1, respectively). (3) Climate forcing was a dominant controlling factor affecting the vegetation, and the anthropogenic behavior exhibited no significant value in the whole region. However, overgrazing was the most important reason for the regional degradation, particularly in IM. (4) In the future, the forest biome will go to recovery, whereas both the grassland and desert biomes are predicted to degrade continuously. 相似文献
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Behaviour of Coupled Modes in a Simple Nonlinear Air-Sea Interaction ModelLiChongyinandLiaoQinghai(LASG,InstituteofAtmospheri... 相似文献
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副热带高压研究回顾及对几个基本问题的再认识 总被引:41,自引:3,他引:41
文中在回顾有关副热带高压研究的基础上 ,指出传统的观念在东太平洋副热带高压和西太平洋副热带高压的关系、下沉运动和副热带高压的形成、热带加热异常与副热带高压异常的关系、副热带高压与其周边系统的关系等问题上存在一定的局限。并根据近期的研究成果对上述问题给出新的认识。最后文中展望了在副热带高压的研究中需进一步深入的几个方面 :不同纬度相互作用、青藏高原的作用、时间尺度 -内部动力过程和外界强迫的相对重要性、非线性过程和角动量平衡问题。 相似文献
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Managing authorities in Scandinavia arrange public information meetings when members of the public express fear because wolves or brown bears approach human settlements. This study aimed to increase the understanding of the potential effect of information meetings on self-reported fear of wolves and brown bears. In total, 198 participants completed questionnaires before and after the information meetings. Nine follow-up interviews were held 1 year later. The quantitative analyses revealed that participants who found the information credible reported a significant increase in social trust and a decrease in vulnerability and fear. The qualitative analyses pointed to the importance of information content and meta-communication, for example, nonverbal cues. It is proposed that, among participants who find the information credible, information meetings may change the appraisal of wolves and brown bears, and therefore they might prove useful as an intervention to address fear of these animals. 相似文献
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李霞 《广东海洋大学学报》2005,25(5):56-59
旅游资源具有公共属性,在旅游资源开发利用过程中相关契约的不完全性导致了产权界定不清,从而会导致负的外部性效果。在分析旅游资源开发利用的外部性问题的性质、特征及其治理难点基础上,进一步就如何治理此类外部性问题进行了探讨。 相似文献
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