增温和氮沉降会影响青藏高原高寒草甸的功能和结构,生态化学计量学有助于揭示植物与土壤之间养分流动的生物地球化学特征。本试验通过在青海高寒草甸进行不同水平增温及氮沉降处理,增温水平分别为W0(不增温)、W1(空气温度增加0.47℃,土...增温和氮沉降会影响青藏高原高寒草甸的功能和结构,生态化学计量学有助于揭示植物与土壤之间养分流动的生物地球化学特征。本试验通过在青海高寒草甸进行不同水平增温及氮沉降处理,增温水平分别为W0(不增温)、W1(空气温度增加0.47℃,土壤温度增加0.61℃)、W2(空气温度增加0.92℃,土壤温度增加1.09℃)、W3(空气温度增加1.44℃,土壤温度增加1.95℃),施氮水平分别为不施氮、16 kg N/(hm^(2)·a)、32 kg N/(hm^(2)·a),探究植物、土壤及酶碳氮磷化学计量变化及其相互之间的关系。结果表明:与不增温相比,增温显著增加植物地上部全氮、土壤全氮、土壤有机碳、土壤氮磷比及土壤酶氮磷比,显著降低植物地上部碳氮比、土壤酶碳氮比及土壤酶碳磷比。与不施氮相比,氮沉降显著增加植物地上部和根系全氮、土壤有机碳、土壤全氮、土壤酶碳氮比,显著降低根系碳氮比及土壤酶氮磷比。氮沉降及增温的交互作用显著影响土壤有机碳含量及土壤酶碳氮磷化学计量比。通过计算植物组织对土壤元素和酶活性响应的化学计量动态平衡指数,发现增温及氮沉降下植物组织化学计量稳态指标属于严格内稳态。土壤全氮、碳氮比、β-1,4-木糖苷酶对植物营养元素及其化学计量有显著影响。综上所述,短期增温及氮沉降处理下青藏高原高寒草甸土壤及酶化学计量会影响植物对养分的获取能力。展开更多
In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainti...In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainties in the response mechanism of stability of plant community biomass in alpine meadows of the Qinghai-Xizang Plateau,China to these two major climate factors.Given this,based on field control experiments,this study systematically evaluated the effects of different levels of climate warming(W0(no warming),W1(air temperature increased by 0.47℃ or soil temperature increased by 0.61℃),W2(air temperature increased by 0.92℃ or soil temperature increased by 1.09℃),W3(air temperature increased by 1.44℃ or soil temperature increased by 1.95℃)),nitrogen deposition(N0(0 kg N/(hm^(2)·a)),N16(16 kg N/(hm^(2)·a)),and N32(32 kg N/(hm^(2)·a))),and their interactions on plant community biomass and its temporal stability,and explored its potential regulatory mechanisms.The results showed that the biomass of total community,Gramineae,and dominant species increased significantly with increasing temperature,but the biomass of common and rare species decreased significantly.Nitrogen deposition also significantly promoted the biomass accumulation of community and gramineous plants.Under the treatment of W3N32,the biomass of plant community,Gramineae,and dominant species reached the highest values,indicating that there was a synergistic effect under this treatment.Structural equation model showed that increasing temperature significantly decreased the stability of plant community biomass by reducing the stability of grass and dominant species biomass and weakening species asynchronism.Interaction of increased nitrogen deposition and temperature increased the biomass fluctuation of grass functional group,thus amplifying its negative influence on community stability.More attention should be paid to the response and regulatory mechanisms of dominant species and functional groups under global climate change.This study provides a theoretical basis for revealing the stability maintenance mechanism of alpine grassland and also provides scientific support for the development of future grassland ecosystem management and assessment.展开更多
揭示气候变暖对土壤微生物多样性及组成是生物多样性和生态系统功能研究的热点。关于不同水平增温如何影响高寒草甸生态系统土壤微生物群落在一定程度上是未知的。本试验在青海玉树州高寒草甸进行不同水平增温试验(W1、W2和W3分别代表...揭示气候变暖对土壤微生物多样性及组成是生物多样性和生态系统功能研究的热点。关于不同水平增温如何影响高寒草甸生态系统土壤微生物群落在一定程度上是未知的。本试验在青海玉树州高寒草甸进行不同水平增温试验(W1、W2和W3分别代表增温幅度逐渐增加),基于高通量测序对土壤微生物群落进行了研究。结果表明:(1)气候变暖会显著增加土壤细菌α多样性及β多样性。其中,土壤细菌Shannon指数在W1、W2和W3处理下分别显著增加了2.70%、3.87%和8.73%,而在W3处理下土壤细菌Chao1指数显著增加了17.82%(P<0.05)。(2)细菌的优势菌门均为酸杆菌门和变形菌门,真菌的优势菌门均为子囊菌门和担子菌门。随着温度增加,细菌富集类群的数量增加,而真菌的数量减少。(3)基于PICRUSt及FUNGuild数据库对细菌及真菌进行功能预测,气候变暖后细菌优势潜在代谢功能及真菌生态功能类会发生变化。其中,不同水平增温处理下土壤相对丰度大于2%的功能基因包括Biosynthesis of ansamycins和Biosynthesis of vancomycin group,以及Valine、leucine和isoleucine biosynthesis等生物合成通路。气温升高会增加未分类腐生真菌及丛枝菌根的相对丰度。以上表明,气候变暖后青藏高原高寒草甸土壤微生物群落多样性、组成和功能均会发生变化。展开更多
以玉树藏族自治州称多县高寒草甸为研究对象,采用随机区组试验设计,设置4个氮素添加水平,分别为不添加(N0)、15 g N/m^(2)(N1)、30 g N/m^(2)(N2)、45 g N/m^(2)(N3)。通过测定植物生物量、植物及土壤养分等指标,探究生物量和化学计量...以玉树藏族自治州称多县高寒草甸为研究对象,采用随机区组试验设计,设置4个氮素添加水平,分别为不添加(N0)、15 g N/m^(2)(N1)、30 g N/m^(2)(N2)、45 g N/m^(2)(N3)。通过测定植物生物量、植物及土壤养分等指标,探究生物量和化学计量特征对氮素添加的响应。结果表明:氮素添加后生物量与养分化学计量间存在显著相关性,其中氮素添加后植物地上部生物量与植物地上部氮含量呈极显著正相关(P<0.01),与植物地上部氮磷比呈显著正相关(P<0.05),与植物地上部碳氮比呈极显著负相关(P<0.01);植物总生物量与植物地上部碳氮比呈极显著正相关(P<0.01),与植物地上部氮含量呈极显著负相关(P<0.01),与植物地上部氮磷比呈显著负相关(P<0.05);而根系生物量与植物养分及土壤养分间无显著相关性。在氮素添加下植物生物量主要受植物地上部氮含量、氮磷比和碳氮比等影响。综上所述,施氮能通过改变土壤和植物养分含量以及化学计量特征进而影响植物生物量。展开更多
文摘增温和氮沉降会影响青藏高原高寒草甸的功能和结构,生态化学计量学有助于揭示植物与土壤之间养分流动的生物地球化学特征。本试验通过在青海高寒草甸进行不同水平增温及氮沉降处理,增温水平分别为W0(不增温)、W1(空气温度增加0.47℃,土壤温度增加0.61℃)、W2(空气温度增加0.92℃,土壤温度增加1.09℃)、W3(空气温度增加1.44℃,土壤温度增加1.95℃),施氮水平分别为不施氮、16 kg N/(hm^(2)·a)、32 kg N/(hm^(2)·a),探究植物、土壤及酶碳氮磷化学计量变化及其相互之间的关系。结果表明:与不增温相比,增温显著增加植物地上部全氮、土壤全氮、土壤有机碳、土壤氮磷比及土壤酶氮磷比,显著降低植物地上部碳氮比、土壤酶碳氮比及土壤酶碳磷比。与不施氮相比,氮沉降显著增加植物地上部和根系全氮、土壤有机碳、土壤全氮、土壤酶碳氮比,显著降低根系碳氮比及土壤酶氮磷比。氮沉降及增温的交互作用显著影响土壤有机碳含量及土壤酶碳氮磷化学计量比。通过计算植物组织对土壤元素和酶活性响应的化学计量动态平衡指数,发现增温及氮沉降下植物组织化学计量稳态指标属于严格内稳态。土壤全氮、碳氮比、β-1,4-木糖苷酶对植物营养元素及其化学计量有显著影响。综上所述,短期增温及氮沉降处理下青藏高原高寒草甸土壤及酶化学计量会影响植物对养分的获取能力。
基金supported by the Key Research and Development and Transformation Plan of Qinghai Provincial Science and Technology Department(2024-NK-137)the Qinghai Province Science and Technology Commissioner Special Project(2024-NK-P28).
文摘In recent years,many studies have focused on the effects of global climate warming and increased nitrogen deposition on the structure and function of grassland ecosystem.However,there are still significant uncertainties in the response mechanism of stability of plant community biomass in alpine meadows of the Qinghai-Xizang Plateau,China to these two major climate factors.Given this,based on field control experiments,this study systematically evaluated the effects of different levels of climate warming(W0(no warming),W1(air temperature increased by 0.47℃ or soil temperature increased by 0.61℃),W2(air temperature increased by 0.92℃ or soil temperature increased by 1.09℃),W3(air temperature increased by 1.44℃ or soil temperature increased by 1.95℃)),nitrogen deposition(N0(0 kg N/(hm^(2)·a)),N16(16 kg N/(hm^(2)·a)),and N32(32 kg N/(hm^(2)·a))),and their interactions on plant community biomass and its temporal stability,and explored its potential regulatory mechanisms.The results showed that the biomass of total community,Gramineae,and dominant species increased significantly with increasing temperature,but the biomass of common and rare species decreased significantly.Nitrogen deposition also significantly promoted the biomass accumulation of community and gramineous plants.Under the treatment of W3N32,the biomass of plant community,Gramineae,and dominant species reached the highest values,indicating that there was a synergistic effect under this treatment.Structural equation model showed that increasing temperature significantly decreased the stability of plant community biomass by reducing the stability of grass and dominant species biomass and weakening species asynchronism.Interaction of increased nitrogen deposition and temperature increased the biomass fluctuation of grass functional group,thus amplifying its negative influence on community stability.More attention should be paid to the response and regulatory mechanisms of dominant species and functional groups under global climate change.This study provides a theoretical basis for revealing the stability maintenance mechanism of alpine grassland and also provides scientific support for the development of future grassland ecosystem management and assessment.
文摘揭示气候变暖对土壤微生物多样性及组成是生物多样性和生态系统功能研究的热点。关于不同水平增温如何影响高寒草甸生态系统土壤微生物群落在一定程度上是未知的。本试验在青海玉树州高寒草甸进行不同水平增温试验(W1、W2和W3分别代表增温幅度逐渐增加),基于高通量测序对土壤微生物群落进行了研究。结果表明:(1)气候变暖会显著增加土壤细菌α多样性及β多样性。其中,土壤细菌Shannon指数在W1、W2和W3处理下分别显著增加了2.70%、3.87%和8.73%,而在W3处理下土壤细菌Chao1指数显著增加了17.82%(P<0.05)。(2)细菌的优势菌门均为酸杆菌门和变形菌门,真菌的优势菌门均为子囊菌门和担子菌门。随着温度增加,细菌富集类群的数量增加,而真菌的数量减少。(3)基于PICRUSt及FUNGuild数据库对细菌及真菌进行功能预测,气候变暖后细菌优势潜在代谢功能及真菌生态功能类会发生变化。其中,不同水平增温处理下土壤相对丰度大于2%的功能基因包括Biosynthesis of ansamycins和Biosynthesis of vancomycin group,以及Valine、leucine和isoleucine biosynthesis等生物合成通路。气温升高会增加未分类腐生真菌及丛枝菌根的相对丰度。以上表明,气候变暖后青藏高原高寒草甸土壤微生物群落多样性、组成和功能均会发生变化。
文摘以玉树藏族自治州称多县高寒草甸为研究对象,采用随机区组试验设计,设置4个氮素添加水平,分别为不添加(N0)、15 g N/m^(2)(N1)、30 g N/m^(2)(N2)、45 g N/m^(2)(N3)。通过测定植物生物量、植物及土壤养分等指标,探究生物量和化学计量特征对氮素添加的响应。结果表明:氮素添加后生物量与养分化学计量间存在显著相关性,其中氮素添加后植物地上部生物量与植物地上部氮含量呈极显著正相关(P<0.01),与植物地上部氮磷比呈显著正相关(P<0.05),与植物地上部碳氮比呈极显著负相关(P<0.01);植物总生物量与植物地上部碳氮比呈极显著正相关(P<0.01),与植物地上部氮含量呈极显著负相关(P<0.01),与植物地上部氮磷比呈显著负相关(P<0.05);而根系生物量与植物养分及土壤养分间无显著相关性。在氮素添加下植物生物量主要受植物地上部氮含量、氮磷比和碳氮比等影响。综上所述,施氮能通过改变土壤和植物养分含量以及化学计量特征进而影响植物生物量。
