本文選題：關(guān)鍵詞 + 葉片穩(wěn)定碳同位素�。� 參考：《浙江大學(xué)》2013年博士論文

【摘要】：氣候變化尤其是其導(dǎo)致的干旱脅迫對生態(tài)系統(tǒng)的影響及生態(tài)系統(tǒng)對這些脅迫因子的響應(yīng)方式是當(dāng)前生態(tài)學(xué)界研究的熱點問題之一。由于人類活動造成的全球變暖及水資源匱乏對植物個體,群落結(jié)構(gòu)乃至整個生態(tài)系統(tǒng)的穩(wěn)定性都起到了深遠(yuǎn)的影響。所以研究長期水分虧缺對群落結(jié)構(gòu)、種群分布及個體代謝造成的影響及其機(jī)理有著重要意義。本文中,我們通過分析水分利用效率、個體形態(tài)特征及化學(xué)計量比等性狀研究不同植物功能群及群落特征是如何適應(yīng)干旱梯度變化的。 首先,我們分析了葉片穩(wěn)定性碳同位素(δ13C)與植物地上密度-生物量關(guān)系(α)間的相關(guān)規(guī)律。越來越多的研究證明α不是一個恒定的值。爭論依舊存在于到底是什么在改變α值中起著關(guān)鍵作用。通過研究葉片δ13C、植物根冠比、高莖異速比等形態(tài)特征和α值沿著東南到西北的自然干旱梯度變化的動態(tài),我們發(fā)現(xiàn)α值隨干旱脅迫的增大而增加,且與植物水分利用效率協(xié)變。這種協(xié)變主要是由植物根冠比、高莖異速比等形態(tài)變化驅(qū)動的,這種變化是植物在干旱脅迫下為提高水分利用效率而采用的一種適應(yīng)性策略。這一信息將為理解和預(yù)測群落及生態(tài)系統(tǒng)過程提供理論支持。 其次,我們研究了穩(wěn)定碳同位素值(δ13C)在植物功能群間的變化形式及其與干旱梯度相關(guān)因子的互作方式。我們發(fā)現(xiàn),由生活型劃分的功能群間的δ13C在統(tǒng)計學(xué)上表現(xiàn)出顯著性差異,但是在數(shù)值上的差距較小(1‰)。喬木(-26.78‰)和灌木(-26.89‰)具有相似的δ13C,均顯著的高于草本(-27.49‰)。常綠灌木(-25.82‰)的δ13C顯著的高于落葉灌木(-26.92‰)。多年生草本(-26.83‰)的δ13C顯著的高于一年生草本(-27.10‰)。禾草類(-26.46‰)的δ13C顯著的高于非禾草類(-26.96‰)。綜合數(shù)據(jù)顯示,δ13C顯著的負(fù)相關(guān)于年平均降水量(MAP)和年平均溫度(MAT),而顯著的正相關(guān)于緯度和海拔。在尺度的變化上MAP存在一個閾值,如果高于這個值δ13C將不會有顯著的變化。功能群間沿海拔的變化不是一致的。功能群間δ13C的變化很小只在1‰的范圍內(nèi)波動,而環(huán)境因子,如：MAP和MAT對δ13C的影響較劇烈(尺度上超過了4‰)。大多數(shù)功能群的δ13c響應(yīng)環(huán)境變化的方式是一致的,但是它們?yōu)轫憫?yīng)梯度變化而產(chǎn)生的自身變化的速率是不同的。此類信息能夠幫助我們預(yù)測不同功能群應(yīng)對未來環(huán)境變化而產(chǎn)生的分布變化。 第三,我們分析了白刺(Nitraria tangutorum)葉片與根部的氮(N)、磷(P)及N：P沿干旱脅迫變化的規(guī)律。我們發(fā)現(xiàn)在本研究進(jìn)行的區(qū)域里,四月份葉片N和P均高于全球及中國本地物種的值,而在八月又均低于這些值。白刺在四月表現(xiàn)出來的是N限制(平均葉片N：P=11.13),而在八月表現(xiàn)出來P限制(平均葉片N：P=38.78)。葉片與根部中的N和P均是高度自相關(guān)的。四月份,隨著干旱脅迫的增加,葉片和根部的N和P均增加。葉片N：P沿干旱脅迫的增加而不變,根部N：P隨干旱的增加而增加。我們認(rèn)為葉片N：P能揭示不同生長階段的養(yǎng)分供應(yīng)情況,而根部N：P則能說明土壤養(yǎng)分是否虧缺。 以上結(jié)果分別從水分利用效率和氮磷化學(xué)計量方面闡釋了植物群落密度調(diào)控指數(shù)α值干旱脅迫變化的內(nèi)在原因。功能群水分利用效率隨干旱相關(guān)因子改變會潛在影響群落結(jié)構(gòu)特征這一結(jié)果也在側(cè)面支持了α值的變化與水分利用效率相關(guān)這一假說。個體特征及其水分利用效率和氮磷化學(xué)計量隨干旱脅迫定量變化證明群落結(jié)構(gòu)和功能直接或間接的被體型和功能及其相互作用所控制。
[Abstract]:The impact of climate change, especially the drought stress on ecosystems and the response of ecosystems to these stress factors is one of the hot issues in the current ecological research. The stability of plant individuals, community structures and even the entire ecosystem due to global warming and water scarcity caused by human activities will play an important role. It is of great significance to study the effect and mechanism of long-term water deficit on community structure, population distribution and individual metabolism. In this paper, we study how different plant functional groups and community characteristics are adapted to drought gradient by analyzing water use efficiency, individual morphological characteristics and stoichiometry. Change.
First, we analyzed the correlation between the carbon isotopes of leaf stability (delta 13C) and the relationship between the aboveground density and biomass (alpha). More and more studies have shown that alpha is not a constant value. The argument still exists in what is the key role in changing the alpha value. Through the study of leaf Delta 13C, plant root and crown ratio, and high speed ratio Ratio We found that the alpha value increased with the increase of drought stress and covariant with the water use efficiency of plants. This covariance is mainly driven by the morphological changes of plant root and crown ratio, high leaf speed ratio and so on. This change is the increase of plants under drought stress. An adaptive strategy for water use efficiency. This information will provide theoretical support for understanding and predicting the processes of communities and ecosystems.
Secondly, we studied the form of stable carbon isotope value (delta 13C) in plant functional groups and their interaction with drought gradient related factors. We found that the delta 13C between the functional groups divided by life type showed significant differences in statistics, but the difference in numerical values was smaller (1 per thousand). Trees (-26.78 per thousand) and shrubs (-26 .89 per 1000) has a similar Delta 13C, which is significantly higher than that of herbaceous (-27.49 per 1000). The delta 13C of evergreen shrubs (-25.82 per thousand) is significantly higher than that of deciduous shrubs (-26.92 per 1000). The delta 13C of perennial herbs (-26.83 per thousand) is significantly higher than the annual herb (-27.10 per 1000). The delta 13C of Gramineae (-26.46 per thousand) is significantly higher than that of non grasses (-26.96 per thousand). Comprehensive data show that delta 1 3C significant negative phase about annual mean precipitation (MAP) and annual mean temperature (MAT), and significant positive phase about latitude and elevation. There is a threshold for MAP on the scale change. If higher than this value [delta] 13C, there will not be a significant change. The variation between the functional groups along the elevation is not consistent. The change of delta 13C between functional groups is only 1 per thousand. Range fluctuations, while environmental factors such as MAP and MAT have a severe impact on Delta 13C (over 4 per thousand on the scale). The delta 13C of most functional groups is consistent in response to environmental changes, but their rate of change in response to gradient changes is different. This kind of information can help us predict different functional groups. The changes in the distribution of the future environment.
Third, we analyzed the changes of nitrogen (N), phosphorus (P) and N:P in the leaves and roots of white thorn (Nitraria tangutorum). We found that in the region of this study, the leaves N and P in April were higher than those of the global and Chinese native species, but in August they were all lower than those in April. In April, white thorn showed N limitation. (average leaf N:P=11.13), and in August, the P restriction (average leaf N:P=38.78) was shown. The N and P in the leaves and roots were highly autocorrelation. In April, with the increase of drought stress, the N and P in the leaves and roots increased. The leaf N:P did not change along the drought stress, and the root N:P increased with the increase of drought. We recognized that the root N:P increased with the drought. Leaf N:P can reveal nutrient supply at different growth stages, while root N:P can explain whether soil nutrient is deficient.
The above results explain the internal causes of drought stress change from the water use efficiency and the chemical measurement of nitrogen and phosphorus respectively. The result of the change of water use efficiency with drought related factors will potentially affect the structure characteristics of the community. The result also supports the change of alpha value and the water use efficiency in the side. The individual characteristics, their water use efficiency and the quantitative changes of nitrogen and phosphorus stoichiometry with drought stress prove that the structure and function of the community are directly or indirectly controlled by the body shape and function and their interaction.
【學(xué)位授予單位】：浙江大學(xué)
【學(xué)位級別】：博士
【學(xué)位授予年份】：2013
【分類號】：Q945

【參考文獻(xiàn)】

相關(guān)期刊論文 前2條

1 丁明明;蘇曉華;黃秦軍;;歐洲黑楊基因資源穩(wěn)定碳同位素組成特征[J];林業(yè)科學(xué)研究;2006年03期

2 林而達(dá);吳紹洪;戴曉蘇;劉洪濱;劉春蓁;高慶先;李從先;包滿珠;;氣候變化影響的最新認(rèn)知[J];氣候變化研究進(jìn)展;2007年03期

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