矮嵩草草甸几种主要植物对模拟增温的响应

NWIPB OpenIR

	矮嵩草草甸几种主要植物对模拟增温的响应
其他题名	The Responses of Several Dominant Plants to Simulating Warming in the Kobresia humilis Mdadow
	赵建中
学位类型	硕士
导师	刘伟
	2007-06-09
学位授予单位	中国科学院西北高原生物研究所
学位授予地点	西北高原生物研究所
关键词	模拟增温矮嵩草黑褐苔草垂穗披碱草草地早熟禾短穗兔耳草鸟足毛茛
摘要	本项研究采用国际冻原计划（ITEX）模拟增温对植物影响的研究方法，将温棚按从小到大的顺序依次设为A、B、C、D、E 5个温度梯度，主要从植物生长特征方面探讨了六种高寒草甸植物---垂穗披碱草(Elymus nutans)、草地早熟禾(poa pratensis)（禾本科）；矮嵩草(Kobresia humilis )、黑褐苔草（Carex alrofusca）（莎草科）；短穗兔耳草(Lagotis brachystachya) （玄参科）、鸟足毛茛(Ranunculus brotherusii)（毛茛科）对模拟增温的响应。分析了模拟增温对叶片数、叶片高度、分蘖数、花蕾数、匍匐茎数、匍匐茎长度及地上生物量的影响，并进一步探讨了在未来全球变暖的趋势下它们在群落中的功能和作用及其演变趋势。研究结果表明： 1) 从对照至A温室随着温室的减小温度(地表温度和地温)逐渐升高，三年的平均温度在A温室中最大（11.9 OC，11.7 OC），在对照中最小（9.4 OC，9.9 OC）。A温室温度（地表温度和地温)分别与对照相比平均升高了2004年（2.6OC，2.2 OC）、2005年（2.2 OC，2.1 OC）、2006年（2.1 OC，2.0 OC）。 2) 禾本科植物（垂穗披碱草和草地早熟禾）对增温的反应规律基本一致，从对照至A温室随着温度的升高，分蘖数、叶片数、叶片高度和生物量逐渐增加。说明，增温有利于禾本科植物的生长和发育。 3) 莎草科植物（矮嵩草和黑褐苔草）对增温反应的总体变化趋势有所区别，从对照至A温室随着温度的升高，分蘖数、叶片数和生物量在一定的温度范围内达到最大值。矮嵩草的分蘖数和叶片数在E温室达到最大值，而生物量在C温室达到最大值；黑褐苔草的分蘖数和叶片数在D温室达到最大值，生物量在A温室达到最大值，叶片高度均随温度的升高而增加。说明，莎草科植物的生长和发育有一定的阈值温度，超出此温度范围越高或者越低，均不利于它们的生长和发育。 4) 短穗兔耳草从对照至A温室随着温度的升高，叶片数、叶片高度和生物量逐渐增加，而匍匐茎逐渐减少。说明，增温有利于短穗兔耳草的营养生长，却抑制了它的克隆繁殖能力。 5) 鸟足毛茛从对照至A温室随着温度的升高，叶片数、叶片高度逐渐增加，但随着实验年限的增加却逐年减少，在实验第二年花蕾数随着温度的升高逐渐减少；生长期明显缩短。说明，增温不利于鸟足毛茛的生长和发育，如果持续增温鸟足毛茛将会被逐渐淘汰。 6) 标定的六种植物高度变化规律一致，即随着温度的升高高度逐渐增加。随着温度的变化，其它微环境要素(诸如气温、湿度、土壤理化性质等)均发生明显的变化，为了维持种群数量和植物个体本身的正常生长，即使同一种植物也可能会在不同温度梯度上采取不同的适应策略，在持续增温的情况下，有些种逐渐被淘汰，有些种生活力却加强，这必将导致植物群落的结构和功能发生改变。由此预测，在未来全球增温的趋势下，海拔相对较低地区矮嵩草草甸的优势种将会发生改变，优势种矮嵩草有可能被禾本科植物所代替。
其他摘要	Based on the International Tundra Experiment (ITEX) method, we established five different size of chambers as A、B、C、D 、E and F, and examined the simulating warming effects on growth characteristics of Elymus nutans, poa pratensis,Kobresia humilis,Carex alrofusca, Lagotis brachystachya and Ranunculus brotherusii. The responses of the tiller number, leaf number, mean height, buds, stolons and biomass to increasing temperature were analyzed. The function in the community was discussed if the global will be warmer and warmer in the future. The main results were reported as follows: 1） The temperature (surface and underground temperature) increased with the size of the chamber decreasing from CK to chamber A which had the highest temperature of 11.9 OC, 11.7 OC; The temperature was lowest in the CK which were 9.4 OC, 9.9 OC. Compared chamber A with the control, the temperatures increased during 2004(2.6OC,2.2 OC)、 2005(2.2 OC,2.1 OC) and 2006(2.1 OC,2.0 OC). 2） The responses of the gramineous plants (Elymus nutans.&poa pratensis.) to increasing temperature were consistent approximately. The tiller number, leaf number, average heights and biomasses were increased with the temperature from CK to chamber A. The results showed that increasing temperature was propitious to growth of the gramineous plants. 3） The responses of the cyperaceous plants (Kobresia humilis.& Carex alrofusca.) to increasing temperature were non-consistent approximately. The tiller number, leave and biomasses reached to the peak in different chambers. Chamber E had the highest tiller and leave number of the Kobresia humilis., but chamber C had the biggest biomass; The tiller and leave number of the Carex alrofusca reached to the largest in chamber D while the biomass reached to the peak in chamber A. The results showed that the cyperaceous plants adapted to certain threshold temperature. It would be harmful to their growth if temperature beyond this scale. 4） The leaf number, height and biomass of the Lagotis brachystachya was increased with the warming but the stolon number was decreasing from CK to chamber A. It was indicated that the higher temperature was in favors of vegetative growth of the Lagotis brachystachya and restrained to clonal growth of the Lagotis brachystachya. 5） The leaf number and height of the Ranunculus brotherusii was increased with the temperature warming, however, they were decreased year by year. The bud number of the Ranunculus brotherusii was decreased with the temperature increasing in the second year and the growth period was shortened. The results proved that the higher temperature was disadvantageous to growth of the Ranunculus brotherusii and it would be gradually phasing out if the climate becomes warming and warming. 6） The height variation of the experimental plants was uniform, that is to say the average height increased with the temperature increasing. With the change of temperature, other micro-environmental key elements (such as temperature, humidity, soil physics and chemistry nature etc.) changed obviously, in order to maintain population's quantity and individual normal growth, even if the same kind of plants may take different strategy in different temperatures. In a situation that temperature increases continuously, some kinds are eliminated gradually, but some species grow well, this will cause structure and function of the plant community to change. Therefore prediction, if the whole world becomes warmer and warmer in future, the dominant species of the Kobresia humilis meadow would be changed and the Kobresia humilis might be replaced by the gramineous plants in the lower altitudes area.
页数	80
语种	中文
文献类型	学位论文
条目标识符	http://210.75.249.4/handle/363003/3140
专题	中国科学院西北高原生物研究所
推荐引用方式 GB/T 7714	赵建中. 矮嵩草草甸几种主要植物对模拟增温的响应[D]. 西北高原生物研究所. 中国科学院西北高原生物研究所,2007.

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