Using 137Cs technique to quantify soil conservation capacities of different ecosystems in Wolong Natural Reserve, southwestern China

Reliable information about soil conservation capacities of different natural ecosystems is an important reference for the design of targeted erosion and sediment control strategies. The objective of this paper is to quantify the soil conservation capacities of different natural ecosystems that can represent different climatic zones. The 137Cs technique has been used to estimate soil redistribution rates in different natural ecosystems over the past 40 years in Wolong Nature Reserve. The reserve, transiting from the Chengdu plain to the Qinghai-Tibet plateau, maintains rich ecosystems from subtropical to frigid.The net soil erosion rates of 5 selected ecosystems that represent a warm coniferous-broadleaf-mixed forest, a cold-resistant deciduous taiga forest, a cold-resistant shrub, an evergreen cold-resistant taiga servation capacities are reversed in order. The reference inventories for 137Cs in different ecosystems velop effective erosion and sediment strategies in areas with similar climates should consider natural ecosystem types.     

Responses of Woody Plants To Human-Induced Environmental Stresses: Issues,Problems, and Strategies for Alleviating Stress

Forest ecosystems are enormously important to mankind.They not only supply wood,foods,medicines,waxes,oils,gums,resins and tannins,but they also regulate climate, hydrology,mineral cycling,soil erosion,and cleansing of air and water.A variety of natural and human-induced environmental stresses have both beneficial and harmful effects on forest ecosystems.However,human-induced stresses are much more harmful than naturally induced disturbances.Human-induced stresses,which often are catastrophic although avoidable,include defor estation,fire,pollution,flooding,and soil compaction.Such stresses variously injure woody plants,impede vegetative and reproductive growth,and induce mortality,largely by causing physiological dysfunction in plants.Human-induced environmental stresses have led to decimation of forest ecosystems,loss of biodiversity,forest declines,and potential global warming. Short-rotation plantations,especially in the tropics,are increasing rapidly,largely to produce wood quickly.Plantations also stabilize soil,prevent water runoff,provide shelter from wind and heat,and relieve pressure for exploiting natural forests.However,plantations alone are unlikely to satisfy society 's growing needs for the products and services that can be provided by woody plant ecosystems.Hence,several multiple concurrent strategies are urgently needed to lessen the many destructive effects of human-induced environmental stresses on woody plants.These include not only the expansion of plantations but also of agroferestry systems and forest reserves as well as the development of innovative silvicultural techniques with a focus on the preservation of natural forests.Conserving sustainability of natural forests will require a land ethic as prelude to understanding the functioning of forest ecosystems,ecological and physiological impacts of disturbances on ecosystems,and the processes involved in recovery of disturbed ecosystems. Many of the harmful effects of pollution,fire,flooding,and soil compaction can be abated by judicious planning to create and perpetuate the critical components of forest stand structure and species composition.Strategies for continuous production of the products and services that can be supplied by woody plants will need to be reinforced by expanded long-term research and close cooperation among forest biologists,social scientists,economists,and regulatory government agencies.     

基于时空分析的生态保护与修复试点工程实施效果评估——以赣州市为例

以“山水林田湖草生命共同体”为中心思想,从生态系统的格局和质量两个方面,对赣州市山水林田湖生态保护与修复试点工程实施效果进行了综合评估。结果如下：（1）从生态系统格局来看,2015到2018年,赣州市森林、农田和城镇生态系统面积明显增加,超过40%的草地生态系统转变为森林生态系统,且近45%的城镇生态系统面积增量由草地生态系统贡献。此外,多数自然生态系统的斑块破碎化加剧,森林生态系统破碎化现象最为明显,最大斑块指数从54.36降低到37.41,而半自然生态系统最大斑块指数增大。（2）从生态系统质量来看,赣州市归一化植被指数稳定在0.7以上并呈增长趋势,水土流失综合治理面积从16543.8 km²增长到18550.4 km²,重点流域水质基本稳定在Ⅱ、Ⅲ级,城镇生态系统受土壤重金属污染的风险较小,但部分县区农田生态系统受一种或多种土壤重金属污染的风险较大。整体而言,赣州市山水林田湖生态保护与修复试点工程取得了显著成效,较好的完成了实施方案中的规划目标。在进一步的生态保护与修复工作中,应重视赣州市自然生态系统斑块破碎化严重地区、水质出现波动较大的河流断面以及农田生态系统受土壤重金属污染威胁较大的县区。     

西藏原始林芝云杉林雨季林冠降水分配特征

利用2006-2007年对西藏米林县南伊沟原始林芝云杉(Picea likiangensis var.linzhiensis)林林外降水、穿透水和树干茎流定位观测数据,对林芝云杉林的林冠降水再分配特征进行研究。结果表明:西藏南伊沟的年降水量为716.4mm,主要集中在4-9月份,占全年降雨量的86.95%。在林芝云杉的生长季节(4-10月份),林冠截留量为338.6mm,占同期林外降水量的51.60%;林内穿透水量为316.3mm,占同期林外降水量的48.21%;树干茎流量仅为1mm,仅占0.19%。林内穿透水(Tp)、树干茎流(Sf)、林冠截留量(Ip)及林冠截留率(PIp)与林外降水量(p)之间的关系分别为:Tp=0.8622p-3.5229,r=0.9964;Sf=0.0004p1.4586,r=0.9458;Ip=1.2222p0.6341,r=0.874;PIp=253.6p-0.7008,r=0.9732。林芝云杉林雨季林冠降水的分配规律与该森林结构复杂、林分年龄高、胸高断面积大密切相关,说明该森林在涵养水源和保持水土等方面发挥着重要的作用。     

Global climate change and carbon balance in forest ecosystems of boreal zones: Simulation modeling as a forecast tool

The individual-based system of models EFIMOD simulating carbon and nitrogen flows in forest ecosystems has been used for forecasting the response of forest ecosystems to various forest management regimes with climate change. As input data the forest inventory data for the Manturovskii forestry of the Kostroma region were used. It has been shown that increase of mid-annual temperatures and precipitation influence the redistribution of carbon and nitrogen supply in organic form: supply increase of these elements in phytomass simultaneously with depletion of them in soil occurred. The most carbon and nitrogen accumulation in forest ecosystems occurs in the scenario without felling. In addition, in this scenario only the ecosystems of the modeling territory function as a carbon sink; in the other two scenarios (with selective and clear cutting) they function as a source of carbon. Climate changes greatly influence the decomposition rate of organic matter in soil, which leads to increased emission of carbon dioxide. The second consequence of the increase in the destruction rate is nitrogen increase in the soil in a form available for plants that entails productivity increase of stands.     

Using 137Cs technique to quantify soil conservation capacities of different ecosystems in Wolong Natural Reserve, southwestern China

Reliable information about soil conservation capacities of different natural ecosystems is an important reference for the design of targeted erosion and sediment control strategies. The objective of this paper is to quantify the soil conservation capacities of different natural ecosystems that can represent different climatic zones. The ¹³⁷Cs technique has been used to estimate soil redistribution rates in different natural ecosystems over the past 40 years in Wolong Nature Reserve. The reserve, transiting from the Chengdu plain to the Qinghai-Tibet plateau, maintains rich ecosystems from subtropical to frigid. The net soil erosion rates of 5 selected ecosystems that represent a warm coniferous-broadleaf-mixed forest, a cold-resistant deciduous taiga forest, a cold-resistant shrub, an evergreen cold-resistant taiga forest, and an alpine meadow are 0.17, 0.16, 0.13, 0.11 and 0.06 kg·m⁻²·a⁻¹, respectively. Their soil conservation capacities are reversed in order. The reference inventories for ¹³⁷Cs in different ecosystems range from 1658 to 3707 Bq·m⁻² with the altitude. Results of this study indicate that any attempt to develop effective erosion and sediment strategies in areas with similar climates should consider natural ecosystem types. Supported by the National Natural Science Foundation of China (Grant No. 40321101)     

Contrasting patterns of soil N-cycling in model ecosystems of Fennoscandian boreal forests

The low plant productivity of boreal forests in general has been attributed to low soil N supply and low temperatures. Exceptionally high productivity occurs in toe-slope positions, and has been ascribed to influx of N from surrounding areas and higher rates of soil N turnover in situ. Despite large apparent natural variations in forest productivity, rates of gross soil N mineralization and gross nitrification have never been compared in Fennoscandian boreal forests of contrasting productivity. We report contrasting patterns of soil N turnover in three model ecosystems, representing the range in soil C-to-N ratios (19–41) in Fennoscandian boreal forests and differences in forest productivity by a factor close to 3. Gross N mineralization was seven times higher when soil, microbial, and plant C-to-N ratios were the lowest compared to the highest. This process, nitrification and potential denitrification correlated with inorganic, total and microbial biomass N, but not microbial C. There was a constant ratio between soil and microbial C-to-N ratio of 3.7±0.2, across wide ratios of soil C-to-N and fungi-to-bacteria. Soil N-cycling should be controlled by the supplies of C and N to the microbes. In accordance with plant allocation theory, we discuss the possibility that the high fungal biomass at high soil C-to-N ratio reflects a particularly high supply of plant photosynthates, substrates of high-quality C, to mycorrhizal fungi. Methods to study soil N turnover and N retention should be developed to take into account the impact of mycorrhizal fungi on soil N-cycling.     

森林干扰生态研究

陆地上80％的生态系统都已受到了来自人类和自然的各种干扰,森林生态系统也不例外．在各种干扰作用下,尤其是人类不合理的干扰导致世界范围内的森林退化／衰退已成为一个十分严峻的事实,因此,以维持、恢复森林生态系统固有的多种功能为基础,实现高效、稳定、可持续就成为经营森林生态系统的总目标．随着干扰的加剧,近年来生态学界更加关注的是“受干扰”生态系统的研究．干扰对森林生态系统主要生态过程的影响以及森林生态系统对干扰的响应等问题,已成为森林生态研究领域的国际前沿与热点．因此,系统地研究干扰条件下森林生态系统的生态过程,并在此基础上确立干扰森林的经营理论与技术,对中国天然林资源保护等林业工程实施及国家生态安全建设具有重要的科学和现实意义．本文在广泛收集国内外有关森林干扰研究结果的基础上,总结了森林干扰的基本概念,分析了干扰与森林经营的关系,探讨了森林干扰研究领域所涉及的内容和关注的基础问题,提出了森林干扰生态研究的主要内容与方向,对今后干扰森林生态研究和中国天然林保护等林业工程建设具有参考价值．     

植物对有机氮源的利用及其在自然生态系统中的意义

近来大量实验研究表明,许多植物能够在不经矿化的情况下直接吸收、利用环境介质中的生物有机氮,尤其氨基酸类。而且,有些植物利用氨基酸的效率可以与矿质氮源(NH4 、NO3)相当或更高。自然界植物赖以生存的土壤生境中同时存在多种有机氮和矿质氮养分,这是导致植物(至少部分植物)进化产生利用各种不同氮源能力的环境驱动力。土壤中的游离氨基酸尽管含量不高,但其周转快、通量大,理论上可远大于植物的氮需求。尽管植物在与土壤微生物的有机氮源竞争中处于根本性劣势,但土壤中氨基酸的巨大潜在通量和植物相对于微生物的生命周期仍可使植物在长期竞争中获取数量可观的氮。基于植物根对氨基酸的吸收能力、土壤中游离氨基酸库的大小和通量、植物与土壤微生物对氨基酸氮源的竞争以及有关的原位实验结果,近来许多研究者都认为植物有机氮营养在多种生态系统中是重要或潜在重要的。尤其是在一些极地、高山、亚高山、北方针叶林或泰加林生态系统中,由于低温等因素限制有机氮矿化,土壤氨基酸浓度常超过矿质氮(NH4 、NO3-)浓度,氨基酸可能代表着植物的一个主要氮源。认识到现实生态系统中植物对有机氮源利用的重要性意味着传统的矿质营养观念的更新,这将在很大程度上改变人们对某些重要生态过程的理解,并导致对若干生态学中心问题的再认识。研究以森林生态系统为例,阐述了我国开展该领域研究的科学意义和基本框架。     

鼎湖山不同演替阶段森林土壤水分时空变异研究

土壤水分作为森林生态系统水分蓄库的主体,森林土壤水分储量及其时空动态与变异对揭示区域植被恢复与气候变化背景下的森林生态系统水文过程响应与服务功能变化机制具有重要意义。本研究以南亚热带地区典型森林植被演替序列马尾松人工林（Pinus massoniana coniferous forest,PF）-马尾松针阔叶混交林（mixed Pinus massoniana/broad-leaved forest,MF）-季风常绿阔叶林（monsoon evergreen broad-leaved forest,MEBF）为研究对象,依托中国生态系统研究网络森林样地建设与监测统一规范对鼎湖山森林生态系统定位站站区内分布的上述森林类型土壤水分的长期定位观测（2005-2015年）,通过分析各演替阶段森林土壤不同土层（0-15、15-30、30-45、45-60、60-75和75-90 cm）土壤体积含水量观测数据,探究该区域森林植被恢复过程中的土壤水分变化及其时空变异。结果表明：在雨热同期且干湿季明显的南亚热带地区,鼎湖山森林土壤储水量及其时间动态受降雨量的影响显著,森林土壤层对降雨具有强烈的调蓄和稳定作用,伴随PF→MF→MEBF自然演替进程,调蓄水分能力逐步增强。林型间,由初期阶段PF到顶级群落MEBF,森林土壤水分储量逐渐提高,且演替后期林型相对于早期林型,土壤储水量均呈现为较小的年际与年内变幅。干、湿季而言,干季时林型间的土壤储水量差异大于湿季,干季时MEBF和MF土壤含水量分别是PF的1.33倍和1.11倍。从土壤含水量的干、湿季期间变异来看,不同林型各土层土壤含水量的变异系数大小均表现为干季大于湿季;垂直剖面方向上,突出表现为无论干湿季MEBF各层土壤含水量变异均比其他两种林型较为缓和,充分体现了MEBF优越的土壤水分时空调配能力。整体上,伴随PF→MF→MEBF自然演替进程,土壤水分储量及其稳定性逐步提升。     

六盘山林区几种土地利用方式对土壤中可溶性有机碳浓度影响的初步研究

 测定分析了六盘山林区典型天然次生林（杂灌林、山杨（Populus davidiana）和辽东栎（Quercus liaotungiensis）林）、人工林（13、18和25年华北落叶松（Larix principis_rupprechti））、农田和草地中穿透雨、凋落物淋溶液、土壤溶液和渗漏水溶液及地下水和降雨中可溶性有机碳 (DOC)的浓度。结果显示：5～10月,雨水中DOC浓度为0.80～1.60mg•L－1,地下水中在2.43～7.66 mg•L－1。9～10月,穿透雨中DOC浓度为1.78～15.20 mg•L－1,其中天然次生林和人工林比农田和草地中高,这些DOC与地表凋落物碳年形成量正相关显著。凋落物浸泡24 h后淋溶产生的DOC浓度为12.30～64.79 mg•L－1,占凋落物碳贮量比例不足1%;浓度方面,天然次生林比农田和草地分别高400%和153%,人工林比农田和草地分别高194%和50%;比例方面,农田和草地比天然次生林分别高79%和98%、比人工林分别高180%和210%,这些DOC浓度与落叶、小枝、碎小物和腐解物碳贮量的正相关显著。9～10月,0～20 cm土层溶液中DOC浓度为7.88～88.44 mg•L－1,占土壤有机碳密度的比例不足0.1%,它们随土层加深而下降,其中天然次生林和人工林中下降幅度比农田和草地中大;浓度方面,天然次生林、人工林比农田和草地中高,差异主要在0～10 cm土层;比例方面,天然次生林DOC比例比农田和草地中低,人工林比它们高,差异主要在0～10 cm土层;这些DOC浓度与土壤湿度及凋落物层碳贮量正相关显著。5～10月,0～40 cm土层渗漏水中DOC浓度为5.76～58.84 mg•L－1,天然次生林、人工林比农田和草地高,差异主要在0～10 cm土层;它们随土层加深而下降,其中天然次生林和人工林下降幅度比农田和草地中大。这些差异可能由土地利用引起的植被和土壤性质改变及其对水文过程的影响所致,说明陆地生态系统中DOC浓度受土地利用变化的影响较大。     

森林生态系统水源涵养服务功能解析

森林水源涵养功能作为森林生态系统服务的一个重要方面,在国内的研究已有数十年的历史。多数研究中将森林水源涵养功能狭义地等同于森林对降雨的拦蓄能力或对径流的调节能力,而忽略了其对各水文过程的整体性作用以及对气象和土壤因子的综合性影响。此外,在不同研究区域中,对于森林水源涵养功能的理解和研究方法往往一概而论,并未考虑研究区域的自然条件特性和社会经济特征,这使得研究结果的区域针对性不足,限制了对其进一步的应用推广。针对上述问题,在全面分析森林水源涵养的含义和特征之后,定义了不同区域的水源涵养功能内涵和主导服务,并给出了不同区域森林水源涵养功能的适宜计算方法,以期为不同区域森林水源涵养功能的全面提升和水源涵养林生态修复工程提供科学依据。     

海南岛森林生态系统碳储量及其空间分布特征

利用最新的森林资源二类调查分布数据和野外样地调查资料,采用InVEST模型和空间统计分析等方法,研究了海南岛森林生态系统碳储量及其空间分布特征。结果表明：海南岛森林生态系统总碳储量为338.15 TgC,其中地上生物、地下生物、凋落物和土壤的碳储量分别为85.12、18.73、2.90 TgC和231.40 TgC,所占比重依次为25.17%、5.54%、0.86%和68.43%。海南岛森林生态系统平均碳密度为147.66 MgC/hm²,其中地上生物、地下生物、凋落物和土壤碳密度分别为37.17、8.18、1.27 MgC/hm²和101.04 MgC/hm²。不同市县森林生态系统碳储量分布在8.55—35.40 TgC的范围内,最高的是琼中县。不同植被类型中,橡胶林的碳储量最高,占全岛森林生态系统总碳储量的27.72%;热带山地雨林的碳密度最高,达到249.64 MgC/hm²。在海拔梯度上,森林生态系统碳密度呈现先增加后减少的变化特征,在海拔600—1300 m范围内的碳密度最高,碳密度为20...     

林火干扰对森林生态系统土壤有机碳的影响研究进展

林火干扰是森林生态系统特殊而重要的生态因子,可改变生态系统的养分循环与能量传递。研究林火干扰对森林生态系统土壤有机碳的影响,有助于理解森林生态系统中土壤碳固持和碳循环过程,为制定科学合理的旨在减缓全球变化的林火管理策略具有重要意义。从4个方面阐述了林火干扰对森林生态系统土壤有机碳的影响及内在机制:分别从大尺度和小尺度两个方面阐述了林火干扰对土壤有机碳的影响及对森林生态系统碳循环与碳平衡的作用机制;探讨了不同林火干扰类型和林火干扰强度下,土壤活性有机碳对林火干扰的响应机制;阐明了林火干扰对土壤惰性有机碳的影响及作用机制;论述了林火干扰主要通过改变土壤有机碳的输入和输出过程进而影响土壤有机碳的稳定性及内在机制。最后提出了提高林火干扰对森林生态系统土壤有机碳影响定量化研究的4种路径选择:(1)全面比较研究不同林火干扰类型对土壤有机碳循环及其碳素再分配过程的功能特征;(2)进一步阐明林火干扰通过改变植被结构进而影响土壤生物群落结构,剖析土壤碳库循环的内在机制;(3)完善不同时空尺度下林火干扰对森林生态系统土壤碳库周转过程的定量化研究;(4)加强不同林火干扰类型土壤碳库稳定性差异的研究。     

2000—2010年我国重点生态功能区生态系统变化状况

分析了2000—2010年我国水源涵养型、水土保持型、防风固沙型、生物多样性维护型重点生态功能区的生态系统结构、质量与核心服务的变化.结果表明: 近11年来,水源涵养型重点生态功能区的森林、草地面积减少,水体与湿的面积增加,森林、草地、湿地生态系统水源涵养总量增加了2.9%,该类区域需要遏制森林、草地的减少趋势.水土保持型重点生态功能区的农田面积减少,而森林、草地、水体与湿地的面积增加,土壤侵蚀总量减少了28.2%,生态系统土壤保持总量增加了38.1%.防风固沙型重点生态功能区的农田、森林面积增加,草地、水体与湿地的面积减少,单位面积土壤风蚀量下降,单位面积防风固沙服务量有所提升,该类区域多位于干旱半干旱区,需要减少农田面积,优先保护原有生态系统.生物多样性维护型重点生态功能区的草地、荒漠面积减少,其他类型的面积有所增加,人类扰动呈现微弱的上升趋势,该类区域需要减少人类干扰.重点生态功能区应该针对核心服务和保护目标,分类分区开展生态系统保护、改善及其效果的定量综合评估.     

Initial responses of soil CO2 efflux and C, N pools to experimental warming in two contrasting forest ecosystems, Eastern Tibetan Plateau, China

Alpine ecosystems are harsh environments where low temperatures are generally a limiting factor. Predicted global warming is thus expected to have a profound impact on alpine ecosystems in the future. This study was conducted to compare the effect of experimental warming on soils in two contrasting forest ecosystems (a dragon spruce plantation and a natural forest) using the open top chamber (OTC) method in the Eastern Tibetan Plateau of China. The OTC enhanced average daily mean soil temperatures by 0.61°C (plantation) and 0.55°C (natural forest), respectively, throughout the growing season. Conversely, soil volumetric moisture declined by 4.10% in the plantation and by 2.55% in the natural forest. Across all measuring dates, warming increased average soil CO₂ efflux by 10.6% in the plantation and by 15.4% in the natural forest. However, elevated temperatures did not affect the respiration quotient in either forest. Two-stage sulfuric acid hydrolysis was used to quantify labile and recalcitrant C and N fractions in the two contrasting soils. Warming significantly reduced labile C and N fractions in both ecosystems but did not influence the total, recalcitrant and microbial biomass C and N pools. Labile C, N and microbial biomass C showed significant interactions in warming × forest type × season. Irrespective of warming treatments, all measured pools were significantly larger in the natural forest compared to the plantation. Taken together, our results indicate that the lowered soil labile C and N pools may be induced by the increased soil CO₂ efflux. The responses of the natural forest soil were more sensitive to experimental warming than those of the plantation. We conclude that reforestation dramatically lowers soil C and N pools, further affecting the responses of forest soils to future global warming.     

中国东部森林样带典型森林水源涵养功能

通过对我国东部森林样带四个森林生态系统定位研究站（长白山站、北京站、会同站和鼎湖山站）的九种森林类型水源涵养监测数据的分析,研究了水热梯度下不同森林生态系统水源涵养功能。结果表明：在生长季的5-10月份,各森林类型的水源涵养特性表现出较大差异。林冠截留率的大小依次为：阔叶红松林＞杉木林＞常绿阔叶林＞针阔混交林＞季风常绿阔叶林＞落叶阔叶混交林＞马尾松林＞落叶松林＞油松林,最高的长白山站阔叶红松林的截留率是最低的北京站油松林的2.2倍。森林降雨截留量与林外降雨量呈显著的正相关,林冠截留率与降雨量呈显著负相关。枯落物最大持水深（5-10月份）以北京站落叶阔叶林最大,为6.0mm;鼎湖山站的季风常绿阔叶林最小,为1.0mm。0-60cm土层蓄水量最大的是会同站的人工杉木林,为247mm;最小的是北京站的落叶松林,仅为45.5mm;林分总持水量依次为：杉木林＞阔叶红松林＞常绿阔叶林＞针阔混交林＞季风常绿阔叶林＞落叶阔叶混交林＞马尾松林＞落叶松林＞油松林。各林分总持水量主要集中在土壤层,占总比例的90%以上。     

Forest ecosystem services of changbai mountain in china

The forest ecosystem of the Changbai Mountain is the most typical upland temperate forest ecosystem in eastern Asia. It is also of the most primitive vegetation type that came into being through the natural succession of soil and vegetation following volcanic eruption. The forest ecosystem has great importance for maintaining the structures and functions of the watershed ecosystems of the Songhua River, the Yalu River and the Tumen River. We combined physical assessment method (PAM) with the value assessment method (VAM) to evaluate the forest ecosystem services of the northern slope of the, including eco-tourism, forest by-products, timber, soil and water conservation, air purification, and the recycling of nutritive elements. We also assessed the integrated forest ecosystem service and analyzed its dynamics. The service value provided by the Changbai Mountain forest ecosystem amounts up to RMB 3.38 × 10¹² yuan, of which, water conservation is 66%, water conservation and air purification together make up 80%, while the timber value is only 7%. Therefore, developing the ecosystem services besides timber is the best way to exert the integrated value of the forest ecosystem services of Changbai Mountain.     

湖南乌云界自然保护区典型生态系统的土壤持水性能

土壤持水性能是决定生态系统水源涵养能力的关键,是自然保护区生态服务功能的重要方面。以湖南省乌云界自然保护区为研究区域,选取森林、灌丛、竹林和草地4个典型生态系统,采用野外调查采样和室内分析的方法研究了土壤的物理性质和持水性能。结果表明,乌云界4种典型植被下表层0—20cm土壤有机质含量普遍较高(>76 g/kg)、容重较低(<0.85 g/cm3)、团聚体稳定性较强(>5mm水稳性团聚体达22.7%—52.3%),表明保护区土壤的结构发育总体上较好。森林和竹林土壤具有较多的大孔隙和较高的饱和导水率,有利于天然降水向地下水的转化,而灌丛和草地土壤毛管孔隙度则相对较高,其土壤中能够保持更多的有效水分。乌云界自然保护区4个典型生态系统0—40cm土层土壤重力水容量为:森林(83.5 mm)>竹林(79.2mm)>灌丛(66.9 mm)>草地(43.8 mm),有效水容量为:草地(128.7 mm)>灌丛(111.6 mm)>森林(95.9 mm)>竹林(83.9mm)。在明晰土壤总蓄水容量(>0 MPa)、重力水容量(0—0.01 MPa)、有效水容量(0.01—1.5 MPa)、无效水容量(>1.5 MPa)等概念的基础上,建议用重力水容量和土壤有效水容量两个指标来评价生态系统土壤的水源涵养功能,其中土壤重力水容量可以反映生态系统补充地下水和调控河川径流量的能力,而土壤有效水容量可以反映生态系统本身保蓄水分的潜力,这些指标均可以通过土壤水分特征曲线进行求算。乌云界自然保护区森林和竹林土壤对于补充地下水和调控河川径流量的能力较强,而灌丛和草地土壤保蓄水分的能力较强。     

Forest ecosystem services of changbai mountain in china

The forest ecosystem of the Changbai Mountain is the most typical upland temperate forest ecosystem in eastern Asia. It is also of the most primitive vegetation type that came into being through the natural succession of soil and vegetation following volcanic eruption. The forest ecosystem has great importance for maintaining the structures and functions of the watershed ecosystems of the Songhua River, the Yalu River and the Tumen River. We combined physical assessment method (RAM) with the value assessment method (VAM) to evaluate the forest ecosystem services of the northern slope of the Changbai Mountain, including eco-tourism, forest by-products, timber, soil and water conservation, air purification, and the recycling of nutritive elements. We also assessed the integrated forest ecosystem service and analyzed its dynamics. The service value provided by the Changbai Mountain forest ecosystem amounts up to RMB 3.38×1012 yuan, of which, water conservation is 66%, water conservation and air purificatio