关注全球气候变化情境下长江上游生态安全与农林清洁生产
Focus on ecological security and clean production of agriculture forestry in the upper reaches of Yangtz River under climate change scenarios
摘要:植物根系分解是养分元素进入土壤的重要途径之一。为了解径级对根系分解过程中养分元素释放的潜在影响,本研究以川西亚高山针叶林中的粗枝云杉(Picea asperata)为研究对象,采用原位分解试验,研究了云杉3个径级(0-2 mm,2-5 mm和5-10 mm)根系分解过程中钾(K)、钠(Na)、钙(Ca)和镁(Mg)元素浓度、残留率和释放率动态特征。结果表明:4种元素在冬季和生长季节释放模式不同,除Na和Ca外,其它2种元素冬季的释放率...
Abstract: Pinus massoniana plantations have been established around the southern part of China to provide timber or fuelwood. In recent years, widely distributed monoculture P. massoniana forests have been transformed into mixed forests due to various ecological problems, such as the decrease in biodiversity in the forests and the lack of soil nutrients. However, how soil microbial diversity ...
Abstract: Winter snowpack maintains a relatively warm environment for soil microorganisms and modulates soil biogeochemical cycles in cold ecosystems; however, snowpack reduction induced by climate warming may change soil dissolved nutrient leaching and microbial biomass. Here, we performed a snow depth manipulation experiment in an alpine forest on the eastern Tibetan Plateau. We assessed th...
Abstract: Walnut blight caused by Xanthomonas arboricola pv. juglandis (Xaj) is one of the most detrimental diseases affecting walnut quality and production. A screen of 18 walnut genotypes for leaf resistance to Xaj suggested species independent variation and revealed four highly resistant (HR) cultivars (‘96’, ‘91’, ‘Chuanzao2’ and ‘Qingxiang’), while ‘Yanyuanzao’ and ‘Xiangling’ ...
Abstract: Plant litter-derived dissolved compounds leaching is an important process for soil carbon (C) sequestration and nutrient cycling. However, knowledge of the biotic and abiotic drivers of dissolved compound release from litter mixture remains limited. Here, we evaluated the loss of soluble C, N, and P during litter mixtures decomposition across an alpine treeline ecotone, and we sough...
摘要:【目的】评价不同核桃品种/无性系的炭疽病抗性强弱,探讨不同抗性材料受到炭疽病菌胁迫后的生理响应差异,为选育抗病品种提供理论依据。【方法】以18个核桃品种/无性系为材料,通过田间人工接种炭疽病菌鉴定其抗性强弱,测定炭疽病菌侵胁迫下不同抗性材料的过氧化物酶(POD)、多酚氧化酶(PPO)、超氧化物歧化酶(SOD)和几丁质酶活性及丙二醛(MDA)、脯氨酸和可溶性糖含量的差异。【结果】不同核桃品种/无性系间炭疽病...
摘要:为鉴定引起四川盆地地区核桃黑斑病的病原菌,采用组织分离法对病原菌进行分离,利用柯赫氏法则验证其致病性,依据菌株形态学和基于16S rDNA 基因序列分析对病原菌进行鉴定;同时,利用分离的菌株对18个栽培品种(无性系)进行抗病性评价。结果表明,分离菌株的菌落形态与黄单胞杆菌属(Xanthomonas)相似,其16S rDNA 序列与树生黄单胞杆菌(X. arboricola)的(登录号为KP340804.1)同源性高达99%,因此,将引起四川盆地地区核桃...
摘要:土壤微生物群落组成及酶活性是反映土壤肥力的重要指标,且与地貌特征和植被群落密切相关. 为了解岩溶断陷盆地典型植被下土壤生物特征,以云南建水县典型岩溶断陷盆地的4种植被类型—玉米、柑橘、石榴和马尾松为研究对象,采用磷脂脂肪酸生物标记法和酶标板法,对比分析不同植被类型土壤微生物群落和酶活性差异. 结果显示,相比3种人工种植植被,马尾松人工林土壤的有机质、全氮和全磷含量均相对较高. 4种植被土壤磷脂脂肪...
Abstract: Soil fauna are crucial decomposers in terrestrial ecosystems, but how the role of soil fauna varies among climatic conditions and litter substrates remains poorly understood. Here, we conducted a four-year litter decomposition experiment along an elevational gradient (453 m, 945 m, 3058 m and 3582 m) in southwestern China. Two dominant tree species with contrasting leaf traits (conif...
摘要:丛枝菌根真菌(arbuscularmycorrhizal fungi, AMF)在森林土壤养分吸收和转化过程中具有十分重要的作用与地位,其群落结构对森林植被更新和演替敏感响应。为了解亚高山森林转换对AMF 多样性的影响,以川西亚高山岷江冷杉(Abiesfaxoniana)采伐后形成的次生林和粗枝云杉(Piceaasperate)人工林为对象,采用高通量测序法研究了2 种森林土壤有机层(半分解层和分解层)和矿质层AMF 组成和多样性的特征。结果表明:2 种森林...
Abstract: The decomposition of litter carbon (C) fraction is a major determinant of soil organic matter pool and nutrient cycling. However, knowledge of litter chemical traits regulate C fractions release is still relatively limited. A litterbag experiment was conducted using six plant functional litter types at two vegetation type (coniferous forest and alpine shrubland) in a treeline ecotone....
AbstractAimsThe conifer litter is fairly recalcitrant and nutrient poor, and broadleaved litter promotes coniferous litter decomposition by increasing degradable nutrients and promoting microbial metabolism. Mixing Pinus massoniana litter and three broadleaved litters may increase the diversity and abundance of fungal decomposers compared to those in P. massoniana litter and vary depending on t...
Abstract: Aim Litter humification is vital for carbon sequestration in terrestrial ecosystems. Probing the litter humification of treeline ecotone will be helpful to understand soil carbon afflux in alpine regions under climate change. Methods Foliar litter of six plant functional groups was chosen in an alpine treeline ecotone of the eastern Tibetan Plateau, and a field litterbag decompositi...
Abstract: Mixed litter decomposition is a common phenomenon in nature and is very important for the circulation of material through an ecosystem. Different plant functional groups (PFGs) are likely to interact during decomposition. It is unclear how mixed decomposition influences the release of multiple metallic elements, and the biogeochemical circulation mechanism in the alpine ecosystem rema...
摘要:[目的]为了解华西雨屏区亚热带不同植物功能型树种凋落叶功能性状特征,探讨不同植物功能型树种对环境的适应策略.[方法]以四川盆地西缘都江堰灵岩山亚热带森林群落为研究对象,采集了18种树种凋落叶,分为常绿阔叶、落叶阔叶和针叶3个植物功能型,比较分析碳(C)、氮(N)、磷(P)、木质素和纤维素及其化学计量比在不同功能型树种间的变异.[结果]常绿阔叶和落叶阔叶树种凋落叶N含量显著低于针叶树种,C:N比显著高于针叶树种;常绿阔...
【摘要】 【目的】了解四川盆地西缘人工林土壤有机碳组分的分布规律.【方法】采四川盆地西缘4种人工林(柳杉Cryptomeria fortunei、含笑Michelia wilsonii、桢楠Phoebe zhennan和麻栎Quercus acutissima)2个土壤层次(0~20 cm和20~40 cm)的土壤样品,测定土壤总有机碳、颗粒有机碳、轻组有机碳和易氧化有机碳的含量.【结果】麻栎人工林在0~20 cm土壤有机碳、颗粒有机碳和轻组有机碳含量分别为73.40、21.54和19.01 g/kg,显著高于...
摘要:以凋落物为载体的养分归还是生态系统物质循环的主要过程,也是林木生长所需养分的重要来源。相对于其他元素,钾(K)和钠(Na)在调节渗透压方面有着极其重要的作用,且淋溶作用强烈,极易流失,但缺乏必要关注。因此,以海拔3589 m高山峡谷区典型的四川红杉(Larix mastersiana)⁃岷江冷杉(Abies faxoniana)原始林为研究对象,在2015年9月到2016年8月期间调查了不同类型凋落物中K 和Na 元素在不同时期的归还特征。...
Abstract: As an arthropod biocide, naphthalene has been used in studies of the ecological functions of soil fauna for decades. However, its potential non-target effects on soil microorganisms may affect soil mineralization and litter decomposition processes. Therefore, we conducted an experiment with naphthalene adding to soil surface at a rate of 100 g·m-2 per month to examine the potential no...
摘要:镉(Cd)是一种有害重金属元素,能够伴随溪流水体流动和物质沉积影响下游流域的生态环境安全,但缺乏必要关注。 为 了解森林溪流Cd储量及其分配的动态变化特征,以岷江上游亚高山森林集水区的溪流为研究对象,在长度10-50、50-150、 150-260m区间内各选取5条典型溪流,研究Cd元素在亚高山森林⁃溪流⁃河流集合生态系统中的迁移过程。 结果表明:亚高山 森林溪流的Cd储量介于2.57-128.46mg/m2之间,主要储存于沉积物中;...
Abstract: Forest fire is a recurrent and serious problem which stirs major environmental, economic, and social concerns. Information on the temporal–spatial distribution of ignition probability and identifying the factors that drive the pattern of forest fire occurrences are the most challenging issues over the world. In this study, the spatial distribution and temporal variation in forest fi...
Abstract: Microbial communities and enzyme activity in soil are the functional link through which the vegetation type occupying a site, may alter soil processes fundamental to nutrient cycling. Roots are known to regulate soil carbon (C) input, but the impacts of different classes of roots on soil microbial community (as indexed by PLFAs) and enzyme activity are uncertain. Thus, the aim of th...
Abstract: Winter snow cover is a major driver of soil microbial processes in high-latitude and high-altitude ecosystems. Warming-induced reduction in snow cover as predicted under future climate scenarios may shift soil bacterial communities with consequences for soil carbon and nutrient cycling. The underlying mechanisms, however, remain elusive. In the present study, we conducted a snow manip...
Abstract: The degradations ofCellulose andligninfrom litterarecrucialprocesses forcarbon andnutrientcycling in forest ecosystems. However,theeffectsofsoilfaunaonthesedegradationprocesses areunclear despitetheirfunctional roles in litter fragmentation and microorganism regulation. Here we conducted a four-year field experiment using litterbags with two mesh sizes (3 and 0.04 mm) to assess the e...