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1.
桉树人工林生态退化与恢复研究进展   总被引:13,自引:0,他引:13  
针对近年关于桉树人工林生态环境效应的争论,简要分析了国内外在桉树人工林生态退化与恢复领域的最新研究进展,并形成3点认识:桉树人工林生态退化通常表现为林地土壤退化、生物多样性减弱和生产力下降,而林地水土流失、人类不合理活动及桉树的化感作用是导致生态退化的重要原因;桉树人工林的生态恢复必须采取科学的技术对策,如开展水土保持、保护生物多样性、调控林地生产力;未来对桉树人工林生态退化及其恢复研究的主要方向可能是从多学科交叉的角度和在分子、细胞水平上研究桉树的生态适应性与生态环境效应,其重点是探索桉树与其他外来植物的生态学关系.本文为桉树人工林的持续经营及客观、科学地评价其生态环境问题提供了一定依据.  相似文献   

2.
以广西红壤区桉树人工林、马尾松人工林和天然阔叶林为对象,采用PCR-DGGE以及稀释平板法等现代和传统分析技术,比较分析了不同林分土壤生物学性状以及细菌群落结构的特征。结果表明:桉树对林地土壤可培养微生物数量的影响效果虽逊于天然阔叶林树种,但与广西乡土树种马尾松之间并无显著差异。此外,桉树人工林土壤中涉及碳、氮、磷循环的土壤酶活性低于天然阔叶林和马尾松人工林,同样表征土壤肥力的微生物生物量碳、氮指标也逊于天然阔叶林,但微生物生物量碳和氮在两种人工林之间无规律性的差异。同时,桉树人工林土壤细菌多样性指数(H)、丰富度(S)以及均匀度(EH)指数均逊于天然阔叶林,但与广西乡土树种马尾松之间的差异并不显著。桉树对林地土壤肥力及生态环境的影响效果虽不及天然阔叶林树种,但与广西乡土树种马尾松林的生态效应相仿。  相似文献   

3.
桉树属于一种速生造林树种,适应性非常强,是林浆纸一体化发展的优势树种,桉树的发展对改变纸浆原料结构、加速纸浆业的发展起到了重大作用。但是近些年,桉树人工林发展过程中存在很多问题,不仅影响了桉树的健康生长,也阻碍了社会经济的发展。基于此,对广西桉树人工林可持续发展中存在的问题进行分析,并提出有效的解决对策。  相似文献   

4.
短轮伐期桉树林发展现状与前景分析   总被引:1,自引:0,他引:1  
简单概述短轮伐期桉树林发展与其加工利用的现状,分析短轮伐期桉树人工林作为实木用材在发展与利用过程中存在的问题及其发展的潜力,指出桉短轮伐期桉树人工林实木利用具有很好的发展前景及其对生态上环境的影响。建议将桉树人工林培育与加工利用结合起来进行研究,实现短轮伐期桉树人工林作为实木用材树种的定向培育、合理高效利用。  相似文献   

5.
云南牟定三种人工林森林水文生态效应的研究   总被引:10,自引:1,他引:10  
利用标准径流小区技术,对云南牟定三种人工林进行了森林水文生态的研究,研究表明,在森林树种个体水文生态作用方面,直干桉和黑荆树冠截留能力比云南松强,而云南松树干茎流量较高,直干桉树冠下降雨量比云南松,黑荆要大,三种树种水文生态作用的差异与其树种的生物学特征物性有关,在人工林群落调控地表径流方面,直干桉一黑荆混交林和云南松人工林群落与无林地对照,直干桉人工林群落相比,具有强调控径流的能力,几种树种树冠下降雨量,树干茎流量,树冠截留量与降雨量有很好的相关性,可以用线性回归方程来模拟,人工林群落对径 的调控,主要体现在人工林群落使地表径流发生频率降低,径流量减少,人工椅群落对径流的调控能力是的无林地的四倍,但是在高的降雨强度下,这种调控能力会明显降低。  相似文献   

6.
桉树在我国拥有悠久的种植历史,具有很高的经济价值。桉树人工林所培育的树种木材质量较好,且生长速度较快,具有良好的耐磨损性。但是因为缺乏实践经验,当前我国部分地区的桉树人工林在木材加工过程中还存在一些问题,严重影响木材加工的质量。对桉树人工林木材加工的相关问题进行深入分析,并提出一些合理的建议。  相似文献   

7.
粤北地区是华南地区的重点林区,因生态发展的需要,目前正进行成熟针叶林和桉树人工林更新改造,更新树种的选择直接影响改造林分的生态功能和经济效益。西南桦是热带南亚热带地区优良速生乡土阔叶树种,在粤北地区引种时间较长,总体表现优良,然而其推广种植明显受温度因子限制。基于此,通过粤北地区冬季几次特殊寒潮后西南桦受害程度和恢复情况的跟踪调查,分析粤北地区西南桦对低温的适应性,进而探讨西南桦在粤北及其周边地区推广种植的可行性和需要注意的问题,旨在为该地区西南桦人工林发展提供科学依据。  相似文献   

8.
桉树具有生长快速、适应性强的优点,是我国引入最成功的造林树种之一,对我国的经济效益和社会效益有重要作用。但在桉树人工林广泛种植过程中,也给生态环境带来了比较多的问题,其中最重要的便是生物多样性的减少。因此,寻求桉树人工林的可持续发展是当今林业研究发展的重点之一。  相似文献   

9.
随着我国市场经济机制的不断深化,桉树人工林产业体系不断发展,桉树人工林产业规模不断扩大,实现了社会经济效益、生态效益的有效增加,在这个过程中,其产生的一系列生态问题也受到社会各界人士的重视。基于此,分析我国桉树栽植状况,以及桉树栽植生态因素,通过对林下植被的恢复及保护,提升林内生物的多样性。通过对桉树栽植模式及栽植结构的调整,提升林地土壤整体肥力,实现土壤、水资源等的科学化利用,强化桉树种栽植管理方法,满足桉树产业经济可持续发展的要求。  相似文献   

10.
通过调查和研究已经接种有固氮菌的桉树人工林,通过测定桉树胸径和树高、然后计算单株材积,旨在探讨接种固氮菌后对桉树人工林生长指标的影响。从实验结果可以看出:接种固氮菌可以有效的提高桉树胸径和树高的生长,同一树种接种不同的固氮菌株,对桉树促生的效果有明显差异性,其中促生效果最佳是固氮菌N2。  相似文献   

11.
生态管理对茶园节肢动物群落结构和多样性的影响   总被引:5,自引:0,他引:5  
以广西融水县红水乡元宝山茶业公司茶园为试验基地,研究了生态管理对茶树节肢动物群落结构和多样性的影响。结果表明:与常规管理茶园比较,生态管理茶园节肢动物群落的物种组成增加15科、84种;害虫类群的个体数量减少55.9%,天敌类群的个体数量增加188.4%;生态管理茶园节肢动物群落的丰富度、多样性指数、均匀度显著高于常规管理茶园,优势指数和群落相似性指数等指标显著低于常规管理茶园。生态管理方式能够提高和恢复茶园节肢动物群落的多样性,有助于实现对茶树害虫的生态控制。  相似文献   

12.
With an increasing proportion of natural forests being replaced by plantations, there is a need to determine their potential to fulfill ecological purposes other than wood production. This study evaluated the extent to which deciduous and coniferous plantations develop understory attributes comparable to those of naturally regenerated stands. A functional group approach was used to synthesise species responses in terms of their ecological traits. Multivariate analyses of ecological traits revealed 16 emergent groups that shared common traits associated with a similar life history strategy. Responses of these groups, understory structure, and understory environmental conditions to plantation types and stand stages were analyzed and compared to naturally regenerated stands. Clear associations of trait responses to stand developmental stages and plantation types emerged. Light-demanding and wind-dispersed species groups were associated with early-successional stages, while woody groups, ferns and ant-dispersed spring-flowering herbs were associated with late-successional stages. Analyses also revealed an indicator group associated with old naturally regenerated forest. The understory functional groups and environmental conditions of deciduous plantations converged toward those of old naturally regenerated forests. However, understory structure in deciduous plantations remained poorly developed and richness of the indicator group was low compared to unplanted stands. Conifer plantations, currently the most common plantation type in the northern hardwood biome, showed a completely different pathway of understory development. Modifications to current plantation management practices are proposed to help recreate or maintain natural understory biological and physical attributes.  相似文献   

13.
桉树取代马尾松对土壤养分和酶活性的影响   总被引:2,自引:0,他引:2  
桉树取代马尾松造林是我国南方典型土地利用变化类型之一,为了探讨该土地利用变化对土壤质量的影响,采用成对设计方法,研究了我国广西桉树取代马尾松造林对土壤养分、微生物生物量和酶活性的影响。结果表明:桉树取代马尾松造林后,土壤全碳、易分解碳库、中等易分解碳库、难分解碳库、全氮和碱解氮含量显著降低,但速效磷显著增加,这可能是由于桉树林施肥和磷素在土壤中移动性弱导致;土壤微生物生物量碳、氮、酚氧化酶、过氧化物酶、蛋白酶、脲酶和酸性磷酸酶活性显著降低。树种变化、桉树林轮伐期短、林下植被差、炼山、翻耕等可能是土壤养分、微生物和酶活性降低的驱动因子;施肥有助于缓解土壤养分降低。在林地转变和经营时,适当保持林下植被和凋落物、减少土壤扰动和合理施肥将有助于改善土壤质量,实现桉树林的可持续经营。  相似文献   

14.
通过测定和比较分析海南桉树人工林和橡胶人工林的林下植物多样性、土壤水分物理特性以及林下物种多样性与土壤水分物理性质的关系,结果表明:(1)桉树林下植物种类共有22种,分属14科20属,橡胶林下植物种类共有25种,分属15科22属。(2)两种森林的土壤容重总体表现为表层小于底层,表土层中桉树林的土壤容重均大于橡胶林,而中下层的土壤容重是前者小于后者;土壤总孔隙度均随深度增加呈减小趋势,在表土层中,橡胶林土壤总孔隙度大于桉树人工林,而在底土层中两种林型接近;橡胶林的毛管孔隙度随土层增加呈递减趋势,桉树林是先减小后增加;在表土层,两种林型的土壤非毛管孔隙度表现为橡胶林大于桉树林,在底土层两种林型基本一致。两种森林的土壤毛管持水量、最大持水量、土壤田间持水量、土壤排水能力均为:橡胶林大于桉树林。(3)与橡胶林相比,桉树林植物多样性与土壤物理特性相关性较小,而负相关程度较高;土壤毛管孔隙度、排水能力对桉树林下物种多样性起促进作用,而非毛管孔隙度、田间持水量起抑制作用;橡胶林物种多样性与毛管孔隙度及非毛管孔隙度呈正相关,与最大持水量、田间持水量及排水能力呈负相关。因此,橡胶林下物种多样性、土壤水分物理特性均优于桉树林,控制两种人工林林下物种多样性大小的土壤水分因子是不同的。  相似文献   

15.
本文通过连续5年监测桉树-牧草和桉树纯林地表径流量和土壤侵蚀量,以及种植前后土壤肥力指标,综合分析间种牧草对桉树林地水土流失和土壤肥力的影响,为桉树人工林科学经营提供理论依据。结果表明:桉树纯林地表径流量和土壤侵蚀量分别在27.4~6612 m~3 hm~(-2) a~(-1)和0~14.9 t hm~(-2) a~(-1)之间,表现出随着种植时间呈逐年减少的变化规律,且水土流失主要集中在前2年;桉树-牧草复合经营模式下林地地表径流量和土壤侵蚀量与桉树纯林随种植时间的变化规律一致,但均低于桉树纯林,降低幅度为20.84%~82.85%;与种植前比,桉树-牧草和桉树纯林土壤pH值分别提高了0.03~0.05和0.14~0.18,有机质、全氮、全磷、全钾、碱解氮、有效磷和速效钾均得到提高(土壤交换性钙和镁除外),增幅分别为0.13~3.00倍和0.39~2.11倍;土壤肥力的关联度从大到小的排列顺序为:桉树-牧草桉树纯林种植前;桉树-牧草和桉树纯林0~20 cm土层土壤肥力指标增幅和关联度均大于20~40 cm土层。可见,与桉树纯林比,间种牧草更有利于改善桉树林地土壤肥力,促进桉树林地可持续性经营,是一种较好的桉树林地复合经营模式。  相似文献   

16.
桉树造林的土壤物理性质及其水文效应   总被引:1,自引:0,他引:1  
为探讨广西主要长周期人工林改为短周期桉树人工林后林地土壤水文功能变化,采用野外采样与室内测试分析相结合的方法,分别研究了1,3,5年生桉树人工林及与之对应的桉树造林前米老排林、杉木林和马尾松林土壤基本物理性质与水分调蓄功能的差异。结果表明:桉树造林后与造林前的长周期人工林相比,土壤蓄水能力的变化主要表现为20—40 cm土层土壤水库容和剩余蓄水空间增加。随着土层深度的增加,土壤容重逐渐增大,饱和持水量、总孔隙度逐渐减小,同时,土壤水库容和剩余蓄水空间也呈现逐渐减小的趋势。桉树造林对土壤物理性质的影响主要集中在土壤的20—40 cm土层,而桉树林对土壤的蓄水能力存在的影响与轮伐周期较长的人工林相比,主要表现为20—40 cm土层土壤水库容和剩余蓄水空间增加,1,3,5年生桉树人工林的土壤水库容分别比对应的长周期人工林高11.25%,19.14%,14.33%;剩余蓄水空间则分别比对应长周期人工林高9.16%,113.01%,23.62%。而40 cm以下土层的土壤蓄水能力却下降。研究结果可为桉树造林的土壤效应评价提供理论依据。  相似文献   

17.
Four major tea management practices (organic, pollution‐free, conventional, and semi‐natural) are employed in Chinese tea plantations at present. These practices can induce changes in the physiochemical parameters, microorganism community and enzyme activity in tea plantation soil. However, understanding of their effects on soil nematodes is still scarce. This study aimed to investigate whether and how different management practices affect the biodiversity, function, and structure of soil nematode communities in tea plantation habitats. The soil nematode community structures and ecological indices were determined from the soil samples collected more than 6 y after their respective farming practices were first applied, and different management practices did not greatly affect soil nematode community evenness or species diversity, but organic practice increased nematode trophic diversity, common species diversity, and species richness. Pollution‐free practice considerably increased fungivorous nematodes, and both pollution‐free and conventional practice decreased bacterivorous nematodes markedly in the subsurface layers of soil. Predator and omnivorous nematodes were found to be more abundant in semi‐natural plantation. Organic practice was more sustainable and suitable for tea cultivation, with the greatest biodiversity, best nutrient conditions, higher and more stable C/N ratio and lower interference in the food web.  相似文献   

18.
土壤是支撑人工林健康生长的基础资源,是营养物质转化和生物多样性保护的主要场所。目前,我国人工林经营中土壤地力衰退问题突出,是制约我国林业生产可持续经营、增大生态安全屏障脆弱性的重要因素。因此,有必要深入认识和理解人工林对土壤地力的影响过程,同时开发保障人工林健康和初级生产力的关键调控技术。本文从土壤物理化学环境、土壤生物群落特性及功能等方面,系统论述了人工林土壤地力的维持机制,重点探讨了林龄结构、林分密度、树种类型等影响人工林地力的地下生态学过程。未来需要关注环境变化下人工林土壤理化性质与生物学性质的耦合机制。现阶段大面积人工林土壤病原菌积累特征不清,土壤病害影响人工林健康的障碍机理也亟待揭示。因此,今后需进一步量化林木健康、土壤生物以及环境之间的互作关系模型,形成从造林配置、过程经营、症状诊断及土壤地力调控等全方位的人工林健康定向调控体系,保障人工林可持续、多目标经营。  相似文献   

19.
Fauna conservation in Australian plantation forests - a review   总被引:1,自引:0,他引:1  
A review of the value for fauna of conifer and eucalypt plantations in Australia is presented. Five key reasons highlight a need for wildlife conservation as part of plantation management. These are: (1) The plantation estate in Australia is set to triple in the coming decades, and where new plantations are located and how they are managed will influence the biota that currently exist in such landscapes. This is particularly critical in many semi-cleared former grazing landscapes where the establishment of new plantations is focused. This is because: (1) (a) native vegetation communities in these areas are poorly represented in the existing reserve system, and, (b) uses such as wood and pulp production need to be balanced with other management values such as wildlife conservation. (2) The maintenance of some elements of the biota within plantations could have benefits for key ecosystem processes like pest control. (3) Although some species cannot be conserved in plantation-dominated landscapes, many species can be through the adoption of (sometimes minor) modifications to forest management. (4) The maintenance (or loss) of biota in plantations is relevant for moves toward ecological standards and the certification of plantations in many parts of the world. And, (5) simple plantation forestry which has a narrow and intensive management focus on producing a forest crop for a limited array of purposes, may not meet societal demands for a range of outputs from plantations in addition to wood and pulp. It also may not be congruent with the principles of ecological sustainability.Our review showed that almost all research undertaken in Australian plantations, both in conifers and eucalypts, highlighted the importance of landscape heterogeneity and stand structural complexity for fauna conservation. At the landscape level, patches of retained native vegetation, strips of riparian vegetation, dams, open and clearing areas can significantly increase the number of native species that occur within plantations. Some species that occur in these areas can also use adjacent planted areas, a result common to conifer and eucalypt plantations. The spatial juxtaposition of stands of varying ages throughout plantation landscapes also can contribute to the maintenance of some populations of native taxa. At the stand level, structural complexity is also important for fauna with many species responding positively to the presence of native understorey plants, the presence of windrowed logs, and logging slash left on the forest floor.The management of plantations to promote landscape heterogeneity and stand structural complexity will, in many cases, involve trade-offs that will influence wood and pulp production. The extent to which this occurs will be dependent on the objectives of plantation management and how far they extend toward the complex plantation forestry model to incorporate social and environmental values in addition to wood and pulp production.  相似文献   

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