Results 11 to 20 of about 4,994 (181)
Dynamics of tannin concentration and nutrient resorption for branchlets of Casuarina equisetifolia plantations at different ages [PDF]
, 2013 通过对福建省惠安县不同林龄短枝木麻黄人工林不同发育阶段小枝单宁含量及氮磷再吸收率的研究,探讨了短枝木麻黄林分发育过程中的营养保存策略。结果表明,幼龄林(5年生)成熟小枝中的总酚(TP)、可溶性缩合单宁(ECT)总缩合单宁(TCT)含量及蛋白质结合能力(PPC)显著高于成熟林(21年生)和衰老林(38年生)。随着林分发育,成熟小枝中n含量显著升高,而P含量呈降低趋势。不同发育阶段林分成熟小枝中n∶P比均大于20,且随着林龄的增加而升高。磷再吸收率(PrE)显著高于氮再吸收率(nrE),均以成熟林分最高 ...
卢昌义 +4 more
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Shuitu Baochi Xuebao, 2022 为了阐明人工梭梭林土壤碳氮磷密度及其生态化学计量特征演变规律,以吉兰泰荒漠区不同林龄(3,6,11,16年)人工梭梭林为研究对象,分析0—20,20—40,40—60 cm土层土壤有机碳(SOC)、全氮(TN)、全磷(TP)密度和生态化学计量特征。结果表明:(1)4种林龄人工梭梭林0—60 cm土层SOC、TN含量及其密度随林龄增加而升高,而TP含量及其密度随林龄增加而降低。其中,3,6年梭梭林SOC、TN含量及其密度随土层深度增加而升高,TP含量及其密度则与之相反;11,16年梭梭林SOC、TN ...
魏亚娟 +6 more
doaj +2 more sources
Shuitu Baochi Xuebao, 2021 为探究秃杉人工林水源涵养功能及其变化趋势，以广西南丹县不同年龄阶段（9，17，25，37年生）秃杉人工林为研究对象，采用室内浸泡法和环刀法分别研究4种林分的林冠层、林下植被层、凋落物层和土壤层持水特性。结果表明：（1）秃杉人工林林冠层和林下植物层持水量分别为18.79~28.37，1.27~4.72 t/hm2，其中林下植物层持水量随林龄增加而显著增大 ...
张日施 +6 more
doaj
Analysis on Stoichiometric Characteristics of a Populus Alba L. var Pyramidalis Protective Forest in Alar Reclamation Area [PDF]
, 2022 [Objective] The contents of C, N, P, and their ecological stoichiometry characteristic contained in foliage, branches, litter, and soil of different age grades of Populus alba L.
Ge Tingjin +5 more
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Spatial and Temporal Changes in Soil Water Erosion in Baisha River Basin from 2007 to 2020 [PDF]
, 2022 [Objective] The spatial-temporal variations of soil water erosion before and after the Wenchuan earthquake in the Baisha River basin of Dujiangyan City, Sichuan Province were assessed to support water source protection efforts and comprehensive control ...
Bao Yuhai +5 more
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Shuitu Baochi Xuebao, 2006 在福建省东山县滨海沙地，开展了不同年龄木麻黄林地根际和非根际土壤养分和酶活性的测定，研究结果表明：（1）不同年龄木麻黄林地根际pH小于非根际土壤，随林龄增长根际土壤和非根际土壤pH值均表现为下降趋势；根际土壤有机质、全氮和水解氮含量高于非根际土壤，各土层有机质含量在中龄林时最大；从中龄林阶段至过熟林，水解氮含量下降；全磷和速效磷含量从幼林发育至中龄林、近熟林逐渐减少，至过熟林略有恢复；根际土壤全钾、速效钾含量呈增加趋势。（2）不同年龄木麻黄林地根际CEC值、水解性总酸度、交换性盐基总量、交换性Mg^2 ...
叶功富 +5 more
doaj +2 more sources
Growth and Management Effect of Larix Principis-rupprechtii Plantation [PDF]
, 2023 [Objective] The effect of growth and management of a Larix principis-rupprechtii plantation was analyzed in order to provide a reference for the scientific and rational management of L.
Jia Baoguang +6 more
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Effects of Plant Density Regulation on Soil Physical Properties and Plant Diversity of Plantations in Yellow River Flood Plain of Northern Shandong Province [PDF]
, 2022 [Objective] The effects of plant density regulation on soil physical properties and plant diversity of different plant stands in the Yellow River flood plain were analyzed in order to provide a theoretical basis for optimizing stand growth, improving ...
Chen Ping +3 more
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Shuitu Baochi Xuebao, 2020 为了解不同林龄柳杉人工林枯落物的水源涵养能力，为森林水土保持措施的确定和实施提供依据，于2018年10月选取平坝区大坡林场5个龄组柳杉人工林作为研究对象，采用烘干法和实验室浸水法对枯落物的持水性能进行研究，并采用熵权法对柳杉人工林5个龄组枯落物水源涵养能力进行综合评价。结果表明：（1）随着柳杉人工林的生长发育，枯落物储量及持水特性呈现先增加后减小的趋势，表现出成熟林最大，幼龄林最小。其中成熟林枯落物厚度为7.40 cm，蓄积量为2.21 t/hm2，最大持水量为6.46 t/hm2，最大持水率为265 ...
杨家慧, 谭伟, 卯光宪, 冯艳
doaj
Comparasion study on the effects of mangrove wetland sediments on the sequestration of typical sulfonamides from the estuarine water [PDF]
, 2015 作为陆地污染物进入海洋的屏障，红树林已然成为众多典型污染物汇聚的场所之一。近年来，海产养殖业的大肆兴起更是加重了抗生素在红树林区的直接污染。锁定态是控制土壤抗生素归宿的主要因素，具有环境存在时间长，危害大等特点，可通过再释放重回到环境中，对环境造成长期危害。对典型磺胺类在红树林群落沉积物中锁定能力的研究对于探索抗生素在红树林区的环境行为和红树林湿地抗生素污染控制及修复功能评估具有现实意义。本文选取了12种水产、禽畜及人用较为频繁的典型磺胺类药物，分别为磺胺甲噻二唑(sulfamethizole,SMT)、
张宇
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