本文選題：穩(wěn)定同位素 + 珍稀瀕危植物�。� 參考：《中國(guó)林業(yè)科學(xué)研究院》2016年博士論文

【摘要】：水是干旱和半干旱地區(qū)生態(tài)系統(tǒng)過(guò)程和功能最重要的限制因子,它對(duì)植物生長(zhǎng)發(fā)育、生存和分布起到關(guān)鍵作用。中國(guó)內(nèi)蒙古西鄂爾多斯荒漠分布著四合木(Tetraena mongolica)、沙冬青(Ammopiptanthus mongolicus)、綿刺(Potaninia mongolica)、半日花(Helianthemum songaricum)等古地中海孑遺植物。這4種珍稀瀕危植物的水分利用策略是植物長(zhǎng)期適應(yīng)進(jìn)化形成的,而植物對(duì)氣候變化(特別是降水格局變化)的響應(yīng)受到其自身水分利用策略的影響。因此,研究這4種珍稀瀕危植物的水分利用策略對(duì)于保護(hù)西鄂爾多斯古地中海孑遺植物、維護(hù)該地區(qū)物種多樣性、維持區(qū)域生態(tài)系統(tǒng)平衡等具有重要的理論和實(shí)踐意義。本研究以西鄂爾多斯荒漠珍稀瀕危植物四合木、沙冬青、綿刺、半日花及其非瀕危植物霸王(Sarcozygium xanthoxylum)為研究對(duì)象,利用氫、氧、碳穩(wěn)定同位素技術(shù),結(jié)合植物群落結(jié)構(gòu)、土壤結(jié)構(gòu)和植物生理生態(tài)學(xué)特征和環(huán)境因子(降水量、溫度等)及多元線(xiàn)性混合模型等手段,分析判定了這5種植物的水分來(lái)源,定量闡明了這5種植物在不同降水條件下的植物水分利用率和水分利用效率,闡明其水分利用策略。得出主要結(jié)論如下:西鄂爾多斯地區(qū)夏季大氣降水線(xiàn)方程(LMWL)為δD=7.287δ18O+1.170(R2=0.937,n=38);降水量效應(yīng)顯著,溫度效應(yīng)不顯著;夏季降水受西風(fēng)氣團(tuán)、局地蒸發(fā)氣團(tuán)以及東南和西南季風(fēng)氣團(tuán)的影響。西鄂爾多斯荒漠土壤水主要來(lái)源于大氣降水與地下水。小雨(0 mm降水量≤10mm)影響0~10 cm土壤含水量和土壤水δD值,對(duì)表層土壤(0~10 cm)的貢獻(xiàn)率在30%以上;中雨(10 mm降水量≤20 mm)影響0~40 cm的土壤含水量和土壤水δD值;大雨(20 mm降水量≤30 mm)和特大暴雨(30 mm)影響0~100 cm的土壤含水量和土壤水δD值,降水對(duì)100~150 cm深層土壤水影響不顯著。在土壤剖面中,0~10 cm表層土壤水受降水的直接影響明顯,隨著土壤深度增加,影響逐漸減小,貢獻(xiàn)率逐漸降低;40 cm以下深層土壤水δD變化較小,趨于穩(wěn)定。在西鄂爾多斯荒漠,小雨時(shí),降水入滲具有自上而下活塞式下滲的特征;隨著降水量的增大,降水以?xún)?yōu)先流的形式入滲,補(bǔ)給更深層土壤水分或淺層地下水。四合木、沙冬青、霸王植物水分主要來(lái)源于降水與80~150 cm深層土壤水,而綿刺、半日花主要依賴(lài)于降水。小雨(0 mm降水量≤10 mm)時(shí),四合木、霸王和沙冬青主要利用深層土壤水;降雨量越大,這3種植物傾向于利用由降水補(bǔ)給的上層土壤水(0~40 cm)。植物對(duì)不同強(qiáng)度降水的利用率的大小順序依次為:綿刺半日花沙冬青四合木、霸王。降水強(qiáng)度越大,植物對(duì)降水的利用率越高,越有利于四合木、沙冬青、霸王、綿刺和半日花植物的生長(zhǎng)。小雨時(shí),四合木、沙冬青和霸王有競(jìng)爭(zhēng)土壤水分的現(xiàn)象。沙冬青、四合木、霸王、綿刺和半日花植物葉片δ13C平均值的大小順序依次為沙冬青(-23.3‰)四合木(-25.2‰)霸王(-25.8‰)綿刺(-26.6‰)半日花(-26.8‰)。這五種植物的水分利用效率平均值的高低順序依次為沙冬青(5.4 mmol CO2·mol-1 H2O)四合木(4.8 mmol CO2·mol-1 H2O)霸王(4.6 mmol CO2·mol-1 H2O)綿刺(4.3 mmol CO2·mol-1 H2O)半日花(4.2 mmol CO2·mol-1 H2O)。光合速率的高低順序依次為綿刺半日花霸王四合木沙冬青。四合木、沙冬青、霸王、綿刺葉片光合速率日變化具有單峰、雙峰兩種類(lèi)型;半日花葉片光合速率同時(shí)存在單峰、雙峰和三峰曲線(xiàn)類(lèi)型。蒸騰速率的高低順序依次為綿刺半日花霸王,四合木沙冬青。沙冬青、四合木、綿刺和霸王的蒸騰速率日變化具有單峰和雙峰兩種類(lèi)型;半日花葉片蒸騰速率日變化呈單峰型。深根植物沙冬青、霸王和四合木具有低光合、低蒸騰、高水分利用效率特點(diǎn),為耐旱型水分利用策略;而淺根綿刺和半日花具有高光合、高蒸騰、低水分利用效率的特點(diǎn),為避旱型水分利用策略。瀕危植物四合木比同科非瀕危植物霸王的水分利用效率稍高,但光合速率較低、蒸騰速率相似,可見(jiàn),四合木仍具有較強(qiáng)的生存適應(yīng)能力。瀕危植物四合木和同科非瀕危植物霸王的水分利用策略相似,二者共存有競(jìng)爭(zhēng)土壤水分現(xiàn)象。建議在日后進(jìn)行西鄂爾多斯荒漠地區(qū)植被恢復(fù)時(shí),應(yīng)盡量避免同時(shí)種植四合木和霸王。土壤蒸發(fā)水、土壤水和植物水受到強(qiáng)烈的蒸發(fā)作用而在當(dāng)?shù)卮髿饨邓�(xiàn)之下。植物水除了來(lái)源于大氣降水外,主要還來(lái)自土壤水中的混合水。地下水氫氧穩(wěn)定同位素值變化幅度小,較穩(wěn)定,主要來(lái)自于當(dāng)?shù)亟邓难a(bǔ)充,幾乎沒(méi)有受到蒸發(fā)分餾作用的影響,其補(bǔ)給機(jī)制主要有兩種:一是降水通過(guò)土壤緩慢滲入地下水,二是降水以“優(yōu)先流”形式入滲到地下水。
[Abstract]:Water is the most important limiting factor for the process and function of the ecosystem in arid and semi-arid areas. It plays a key role in the growth, development, survival and distribution of plants. The Western Ordos desert in Inner Mongolia, Inner Mongolia, is distributed in the desert (Tetraena mongolica), Ammopiptanthus mongolicus, Potaninia mongolica, and semidiurnal flowers (Helianth). Emum songaricum) and other paleo Mediterranean relict plants. The water use strategy of these 4 rare and endangered plants is the long-term adaptive evolution of plants, and the response of plants to climate change (especially the change of precipitation pattern) is influenced by its own water use strategies. Therefore, the water use strategy of these 4 RARE and endangered plants is studied. It is of great theoretical and practical significance to preserve the species diversity and maintain regional ecosystem balance in the Western Ordos palaeo Mediterranean species, maintaining the species diversity and maintaining the regional ecosystem balance. This study is based on the study of four wood, holly, spines, semidiurnal flowers and the non endangered plant overlord (Sarcozygium Xanthoxylum) of the West Ordos For example, using hydrogen, oxygen, carbon stable isotope technology, combined with plant community structure, soil structure and plant physiological and ecological characteristics and environmental factors (precipitation, temperature, etc.) and multiple linear mixed models, the water sources of these 5 plants were analyzed and determined, and the water benefits of these 5 plants under different precipitation conditions were quantified. The main conclusions are as follows: the summer atmospheric water line equation (LMWL) in Western Ordos region is delta D=7.287 Delta 18O+1.170 (R2=0.937, n=38), the effect of precipitation is significant and the temperature effect is not significant; in summer, the precipitation is affected by the western wind mass, the local evaporation mass and the southeast and southwest monsoon air masses. The desert soil water in Western Ordos mainly comes from atmospheric precipitation and groundwater. Small rain (0 mm precipitation is less than 10mm) affects 0~10 cm soil water content and soil water delta D value, the contribution rate to surface soil (0~10 cm) is above 30%; rain (10 mm precipitation is less than 20 mm) affects 0~40 cm soil moisture and soil water delta D value; heavy rain (20 drops) Water content less than 30 mm) and heavy rainstorm (30 mm) affect the soil water content and soil water delta D value of 0~100 cm, and the influence of precipitation on 100~150 cm deep soil water is not significant. In soil profile, the direct influence of 0~10 cm surface soil water is directly affected by precipitation, with the increase of soil depth, the influence gradually decreases and the contribution rate decreases gradually; the deep soil below 40 cm is below the soil depth. The water delta D changes little and tends to be stable. In the West Ordos desert, the precipitation infiltration has the characteristics of top-down piston infiltration, and with the increase of precipitation, the precipitation is infiltrated in the form of preferential flow, recharging deeper soil moisture or shallow groundwater. Four wood, holly, and rewang plant water are mainly derived from precipitation and 80~150 cm. Deep soil water, while spiny, and semidiurnal flowers mainly depend on precipitation. When small rain (0 mm precipitation is less than 10 mm), four wood, overlord and sand Holly mainly use deep soil water; the greater the rainfall, the 3 plants tend to use the upper soil water supplied by precipitation (0~40 cm). The order of plant utilization rate of different intensity precipitation is in turn as follows: The greater the precipitation intensity, the higher the rainfall intensity, the higher the rainfall intensity, the more beneficial to the growth of four wood, holly, Overlord, spines and semidiurnal flowers. The four wood, the four wood, the four wood, the overlord, the spiny, and the leaves of the semidiurnal plant Delta 13C. The order of the average value is in order of -23.3 per 1000 (-23.3 per thousand) wood (-25.2 per thousand) overlord (-25.8 per thousand) spiny (-26.6 per thousand) semidiurnal flowers (-26.8 per thousand). The order of the average value of water use efficiency of the five plants is in order of the 5.4 mmol CO2. Mol-1 H2O (4.8 mmol CO2, mol-1). (4. 4.6 .3 mmol CO2. Mol-1 H2O) semidiurnal flowers (4.2 mmol CO2. Mol-1 H2O). The order of photosynthetic rate is in order of the four combined wood sand holly. The diurnal variation of photosynthesis rate of four wood, holly, tyrannosus and spiny leaves is single peak, two types in Shuangfeng; the photosynthetic rate of semidiurnal floral leaves is simultaneously single peak, Shuangfeng and three peak curve types The order of transpiration rate is as follows: the order of the transpiration rate in turn is the spiny semidiurnal flower overlord. The diurnal variation of transpiration rate of four wood holly, four wood, spines and tyrannosus has two types of single peak and Shuangfeng; the diurnal variation of the transpiration rate of the leaves of the semidiurnal flower leaves is single peak. The deep root plant, ASP, and four wood are low photosynthetic, low transpiration and high water content. With the characteristics of efficiency, it is a drought resistant water use strategy, while shallow root spines and semidiurnal flowers are characterized by high photosynthesis, high transpiration and low water use efficiency. It is a drought resistant water use strategy. The four wood ratio of endangered plants is slightly higher than that of the endangered plant of the non endangered plant, but the photosynthetic rate is low, the transpiration rate is similar, and four wood trees are visible. The four species of endangered plants are similar to the water use strategy of the endangered plants of the endangered plants, and the two coexist in the competitive soil water. It is suggested that when the vegetation restoration in the West Ordos desert area is restored, it is necessary to avoid the planting of four wood and Overlord at the same time. Soil water, soil water and planting should be avoided at the same time. The water is strongly evaporated and is under the local atmospheric water line. Plant water is mainly derived from the precipitation in the atmosphere, mainly from the mixed water in the soil water. The change of the stable isotope value of the hydrogen oxygen stable isotope is small and stable, mainly from the supplement of local precipitation, which is not influenced by the evaporation and fractionation, and its recharge There are mainly two mechanisms: first, precipitation is slowly infiltrating into groundwater through soil, and two is precipitation in the form of preferential flow into groundwater.
【學(xué)位授予單位】：中國(guó)林業(yè)科學(xué)研究院
【學(xué)位級(jí)別】：博士
【學(xué)位授予年份】：2016
【分類(lèi)號(hào)】：Q948

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相關(guān)期刊論文 前10條

1 智穎飆;李紅麗;崔艷;路戰(zhàn)遠(yuǎn);劉s，

本文編號(hào)：1904659