近期，中国社会科学院民族学与人类学研究所张继焦研究员主持的一项关于气候变化对长江源地区的影响的研究课题顺利结项。该项目由世界自然基金会（WWF）中国分会委托，是WWF长江流域大型项目的重要组成部分。
与自然科学对长江源地区的研究课题（如冰川、冻土、植被、土壤等）不同，由张继焦博士主持的这个研究项目，侧重于从社会科学的角度考察50年以来气候变化对长江源地区的水资源、生态环境、湿地、土地退化和沙化、畜牧业等的影响。该项目的主要成员来自中国科学院昆明植物研究所、中国社会科学院城市发展与环境研究中心、青海省玉树州三江源环境保护协会等，共8人。
这项研究课题通过实地调查得出了几个主要发现或结论：第一，气候变化在长江源地区表现得很显著。它主要表现为“冷季变长了，暖季变短了”，其对草地的影响主要是“牧草质量变差和草地鼠害增加”两个方面。第二，气候变化对长江源地区牧民的生计产生了一些明显的不利影响。主要是影响了牧草返青和生长，也严重影响了牛羊的长瞟、生育、产奶等。第三，气候变化对长江源地区的生态环境也产生了一些负面的影响。92.50%的受访人认为，气候变化与草场退化或沙化的关系较为密切；87.50%的受访人认为，气候变化与草场减少有较为密切的关系。86.50%的受访人认为，草场退化或沙化已经发展到了较为严重的程度；72.00%的受访人认为，草场减少已经发展到了较为严重的程度。第四，气候变化及其影响在长江源地区存在着地域差异性。比如，在高寒沼泽草场和高寒草甸草场是草质变差；在高寒干草原草场是鼠害增加。第五，“过度放牧导致长江源地区生态环境恶化”的说法不完全属实。长江源地区幅员辽阔，无论是当地牧民，还是畜牧干部（如曲麻莱县畜牧局局长），都不认为当地存在着牛羊数量过多或过度放牧的问题。受访的当地畜牧干部和牧民比较一致的看法是：1985年大雪灾之前的牛羊数量达到了历史的最高峰，此后就在也没有到达那个水平。最近一些年来，越来越多牧民的牛羊数量不是在增加，而是在减少。
张继焦研究员还特别指出“当地牧民为什么被忽视了”。50多年来，长江源地区一直是研究青藏高原的自然科学家的重要基地之一，他们研究了当地的冰川、冻土、地貌、动物和植物等。最近一些年来，长江源地区的野生动物、生态环境状况和保护等，已经成为中国中央政府、青海省各级有关政府部门、自然科学界和新闻界，甚至国际环保NGO组织关注的话题。
然而，有谁在关心当地的普通牧民的处境呢？显然，当地牧民作为长江源地区的主体之一被人们给忽视了。在这次调查中，当调查组人员风尘仆仆地深入到一家一户的牧民中，告诉他们：“我们是专门来了解情况的。”他们都很高兴，并积极配合课题组的调查工作。
应对长江源地区的气候变化和生态环境恶化等问题，如果不了解当地牧民的实际情况，如果不把当地牧民作为活动主体之一，再好的科学方法，再好的发展政策和计划，也很难达到良好的效果。当地牧民不能再被忽视了，应该更加关注他们的畜牧经济状况、生活中的困难等，并给予他们一定的帮助。（张继焦）
本文对应英文文稿
Climate Change and Its Impact in the Source Region of
the Yangtze River in The Tibetan Plateau
Zhang Jijiao
(Professor, Ph.D., Institute of Ethnology and Anthropology, Chinese Academy of Social Sciences )
The Tibetan Plateau, the roof of the world and the third pole of the earth, one of the most imposing topographic features on the Earth’s surface, is very sensitive to climate change, which has been recognized in past researches. Its complex landform with high altitude, powerful monsoon circulation and solar radiation make it sensitive to temperature change, which shows that the amplitude of its temperature change is large. Compared to other regions, climatic change in the Plateau is earlier. The Plateau is regarded as a sensitive region to global climate change. The ecosystems on the plateau including wetland respond to global warming rapidly and obviously. Previous research revealed that the glacier and ice cap on the high mountains retreat significantly in the past five decades, which have dramatically impacts on the hydrological regime, temporal and spatial water distribution and availability, water chemistry in the whole river basins. It’s also found that the swamp in this area is shrinking rapidly. In the last two decades, 647 km2 of swamp in the Yellow River source area shrunk and dried up. These changes, both as the result of and response of ecosystems to regional climate change, will directly affect wetland ecosystem, local communities and people living downstream as well.
The Yangtze Source Area is located in the center of the Tibetan plateau, which has an average altitude of 4000 masl and the largest ice mass outside the Earth’s two polar regions. Besides glaciers and snow, the natural coverage of this area also includes alpine steppe, alpine meadow, grassland, swamp, and alpine shrubs.
To address the situation, World Wild Fund (WWF) China supported a project of "Climate Change and Its Impact in the Source Region of the Yangtze River" from 2004 to 2005. The project aimed to integrate climate change into regional planning process for sustainable development in a relative long-term perspective. This project was thus an effort to link important global climate issues with a regional setting in China, as an example of integrating interdisciplinary studies on climate change with adaptation policies and actions in developing countries.
Based on field work in three kinds of the grasslands high-cold marsh meadow, high-cold grassplot meadow, and high-cold steppe meadow of the Source Region of the Yangtze River in 2005, we have some main findings in the following:
1. Climate change was very obvious in the Source Region of the Yangtze River
Among 200 interviewees, most of them (84.50%) realized that it had the most obvious or more obvious climate change in the Source Region of the Yangtze River. In particular, 56.39% of herdsman interviewees recognized that it had the most obvious climate change in the local grassland.
In the Source Region of the Yangtze River, interviewees thought that the distinguishing influences of climate change on local ecosystem included precipitation (14.72%), the plague (13.40%), grass quality (13.21%), and grassland (10.00%).
This means we need to pay more attention to climate change in the Source Region of the Yangtze River, and it is valuable to research the topic of climate change there.
2. Serious harmful influences of climate change on husbandry in the Source Region of the Yangtze River
The local herdsmen’s husbandry and living depends on the climate. So, they are very sensitive to climate changes.
After our visiting one household by one household, we found that the local herdsmen are more sensitive to climate changes in warm season than in cold season, because in warm season grass turn green and grow up, and it is also the important period for livestock growing, calving, lambing and milking. In term of shorter in warm season than before, the local herdsmen explained that the period of warm season were 3-4 months before, but it become only 2 months and more. This climate change has influenced strongly not only grass turning green and growing up, but also livestock growing, calving, lambing and milking.
In the Source Region of the Yangtze River climate change influenced harmfully not only on ecosystem, but also on husbandry. In general, interviewees thought that climate change influenced harmfully and obviously on the three aspects of husbandry: grass quality worsening (15.69%), the plague insect pest increase (14.78%), and illness of livestock increase (10.77%) as well.
The local herdsman’s husbandry had been influenced harmfully by climate change. Some herdsmen had very difficult situation. It means that we need to pay more attention to the herdsman’s husbandry and their living condition because of the great climate change.
3. Serious harmful influences of climate change on ecosystem in the Source Region of the Yangtze River Grassland has the closest relation with herdsman’s husbandry and their living condition in the Source Region of the Yangtze River. Unfortunately, the local grassland has degenerated, desertized and decreased.
86.50% of 200 interviewees pointed out that the grassland degeneration or desertization was in the most serious situation (52.50%) or the more serious situation (34.00%) in the Source Region of the Yangtze River. 92.50% of them recognized that there was the closest relation (61.00%) or closer relation (31.50%) between climate change and grassland degeneration or desertization.
72.00% of 200 interviewees realized that the grassland decrease was in the most serious situation (44.00%) or the more serious situation (38.00%) in the Source Region of the Yangtze River. 87.50% of them agreed that there were the closest relation (52.50%) and closer relation (37.00%) between climate change and grassland decrease.
Overall, interviewees thought that four aspects of climate change influenced harmfully on ecosystem, which included grass quality worsening (20.87%), the plague increase (17.46%), desertization (13.66%), and grassland decrease (10.44%).
As victim, many herdsmen told us that because the ecosystem became worsen, the livestock grew up and calved difficultly, and had less lambing and milking.
Therefore, we need not only pay a attention to the local ecosystem worse, but also pay more attention to influences of climate change on ecosystem, which focused on the local herdsman.
4. Different influences of climate change on ecosystem in different areas
The Source Region of the Yangtze River is an area with a vast territory. There are different climate changes in different areas, there are different influences of climate change on ecosystem in different areas.
On the one hand, there are different climate changes in different areas. For example, in Zhiduo County, the most distinguishing changes were less snow than before in cold season and more snow than before in warm season. However, in Qumalai County, the most distinguishing changes were more gale than before in both cold season and warm season.
On the other hand, there are different influences of climate change on ecosystem in different areas. Among three kinds of the grasslands, higher percentage of interviewees in both high-cold marsh meadow (16.55%) and high-cold steppe meadow(17.84%) thought that the most harmful influence of climate change on husbandry were grass quality worsening. However, 17.99% of interviewees in high-cold grassplot meadow recognized that it was the plague and insect pest increase.
In a word, when we do the project on ecosystem protection in the Source Region of the Yangtze River, we should think about both different climate changes and different influences of climate change on ecosystem in different areas.
5. It is not true that over husbandry resulted in ecosystem worsening in the Source Region of the Yangtze River
In many newspaper reports, government report and research paper, reporters (included journalists, officials, and scholars) pointed out that over husbandry (that is, herdsman has too much livestock.) was one of important factors resulted in ecosystem worsening in the Source Region of the Yangtze River.
However, when we did this survey in the Source Region of the Yangtze River, both many local herdsmen and a husbandry official told us that herdsmen hadn’t too much livestock. 42.50% of interviewees thought that there was not over husbandry here. The local herdsmen and husbandry officials also told us similarly that the amount of the livestock hit an all-time high before the great snow disaster in 1985. Since then, the livestock here never reach the peak. The amount of the livestock has not increased but decreased.
In the Source Region of the Yangtze River, in general herdsman has not too much livestock. In fact, in some areas ecosystem worsen resulted in that herdsmen have too much livestock or their husbandry methods are unsuitable. But those are only some cases or partial problem, but not a widespread and serious problem.
In general, too much livestock and unsuitable husbandry methods are not main factor resulted in ecosystem worsening in the Source Region of the Yangtze River. So, it is valuable to survey and study the violent climate change and the fragile ecosystem in the Source Region of the Yangtze River.
Overall, Climate change was very obvious in the Source Region of the Yangtze River. It has not only obvious harmful influences on ecosystem but also serious harmful influences of climate change on husbandry. In a sense, this project -- social science survey on "Climate Change and Its Impact in the Source Region of the Yangtze River" not only has its own academic value, but also correct a wrong theory "over husbandry resulted in ecosystem worsening in the Source Region of the Yangtze River".
ADDRESS:
Prof. & Dr. Zhang Jijiao
Institute of Ethnology and Anthropology, Chinese Academy of Social Sciences
No.27, Zhongguancun Nandajie Road, Beijing 100081, P. R. China
E-mail: Zhjijiao@sohu.com