共查询到19条相似文献,搜索用时 31 毫秒
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为探究计划烧除对云南松林土壤水文特征的影响,为计划烧除后森林生态系统服务功能评价提供依据,以云南省新平县实施多年计划烧除的云南松纯林为研究对象,设立20 m×20 m计划烧除样地和不进行计划烧除的自然对照样地各3块。2019年2月实施计划烧除作业,进行样地调查、火烧强度和枯落物储量调查,2020年6月采集土样,测定土壤物理、化学性质和土壤入渗性能。结果表明,计划烧除后土壤容重增加且在0~10 cm土层差异显著;毛管孔隙度和总孔隙度减少但差异不显著;有机质减少并在0~20 cm土层差异显著。计划烧除后土壤自然含水率、饱和持水率、毛管持水率和田间持水量减少但差异不显著;吸湿水量减少并且在0~20 cm土层差异显著。计划烧除后土壤初渗速率、土壤平均入渗速率和土壤稳定入渗率减少;土壤初渗速率和平均入渗速率在不同样地0~20 cm土层差异显著。计划烧除对土壤稳定入渗率的显著影响因素为土壤容重、孔隙度、有机质和饱和持水率。说明计划烧除后云南松林土壤持水性能下降,入渗性能下降,对于入渗性能的影响主要是源于土壤理化性质的改变。 相似文献
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计划烧除引起水土流失的定量研究 总被引:3,自引:0,他引:3
首次在国内对计划烧除林地水土流失量进行了定位研究,结果显示计划烧除林地土壤侵蚀强度因坡度变陡而增加,坡度23的试验区为69.5t/(km·a),对照为52.6t/(km·a);坡度33“的试验区为104.7t/(km·a),对照为101.8t/(km·a)。计划烧除林地的土壤侵蚀量远远低干200t/(km·a)这个最低允许流失量标准。可以认为,在林内开展计划烧除所引起的水土流失量是很微弱的。周期性地开展计划烧除产生的生态负效应对环境质量的影响不显著。为了降低森林的燃烧性,大幅度减少森林火灾,积极开展计划烧除不仅必要,而且可行。 相似文献
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对西双版纳自然保护区内思茅松林进行计划烧除的影响情况监测。分析认为,计划烧除对思茅松林的乔木层树种不会产生明显影响,影响较大的是灌木层和草本层植物。在计划烧除过程中,灌木层和草本层植物大部分被烧死,但草本植物在烧除后3个月内已大部分重新萌发,1a后基本达到了烧除前的水平,6个月后灌木树种已基本从死亡植株的基部重新萌发出新的植株。计划烧除对思茅松林不会造成长期的影响,同时由于烧除后郁闭度减小,有利于林下植物的生长和外部植物的进入,可适当增加物种多样性,但丛生的植株对植物的生长有一定的影响。 相似文献
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云南松计划烧除林地危险可燃物累积量动态及计划烧除周期探讨马志贵鄢武先杨道贵(四川省林业科学研究院1前言云南松森林计划烧除技术的大面积推广应用,可减轻云南松林区的防火压力,起到保护森林资源的作用。确定正确的计划烧除周期,可把计划烧除对林地环境质量的影响... 相似文献
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我国计划烧除研究综述 总被引:1,自引:0,他引:1
《林业调查规划》2015,(6)
火是一个重要生态因子,对生态系统的平衡或发展具有重要意义。计划烧除是合理利用林火对森林资源及生态系统进行有效管理的一种有效手段,作为生态系统的一个环节,对生态系统的发展及生物多样性的保护起着重要作用。为了充分了解计划烧除的生态学意义,我国很多学者在林火管理研究的基础上,对计划烧除的生态作用和意义进行了研究,这些研究主要体现在对野生动植物的影响、森林碳汇及计划烧除周期等几个方面。认为要做好计划烧除工作,需要加强我国林火管理政策研究,针对不同的林区采取不同的管理方式,才能达到丰富生物多样性的目的。 相似文献
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计划烧除兴利避害 总被引:1,自引:0,他引:1
火是生态系统中的一个自然因子,是人类生存不可缺少的工具。在人为有效控制下,它能为人类服务,为人类造福;失去人为控制的燃烧,也会破坏生态系统的平衡,因此火具有两重性。采用计划火烧,减少林地可燃物,是一项行之有效的防火措施。一、计划烧除的实施我局从1982年试行计划烧除林内枯枝落叶可燃物,经观察对森林没有大的破坏;1983年再次扩大试验面积500亩,烧除后,从现象上看树林生长正常;1984年扩大到6000亩;1985年扩大到46000亩。试验结果见表。从表中看出,计划烧除在密度大,平均树高6米以下的林分,V级木被烧死,实际是自然稀疏的林下濒死木;密度适中林分平均树高6米以上,受害率仅 相似文献
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在防护专用林、防护型用材林、防护型经济林和防护型薪炭林以2∶1∶1∶1比例配置的条件下,进行长期定位研究,其结果是:(1)在1~4 a期间,红壤区和紫色土区单位面积泥沙流失量分别减少38.98%和36.05%,平均含沙量分别减少41.19%和18.43%; 4~7 a期间,两区域泥沙流失量分别减少99.86%和75.73%,平均含沙量减少97.52%和 78.00%.(2)植被恢复后的第7 a,红壤区的土壤侵蚀量已控制在允许量以内,为3.42 t·km-2a-1;紫色土土壤侵蚀量以养分流失为标准时,在允许量以内,以成土量为标准时,尚有一定距离.(3)红壤水土流失量比紫色土小,在水土流失量的减小速度上大于紫色土区.红壤较紫色土区生态恢复快.(4)降雨量在10.1 mm·d-1以上时,造林1~4 a期间,两类区域均易造成水土流失,水土流失量主要产生于25.1 mm·d-1以上的几场降雨. 相似文献
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《Journal of Sustainable Forestry》2013,32(4):35-59
Abstract Forest thinning accomplished with cut-to-length and whole-tree harvesting systems, and prescribed underburning were assessed for their impacts on water relations in eastern Sierra Nevada Jeffrey pine (Pinus Jeffreyi Grev. & Balf.) during a period of extended drought. Predawn and midday measurements of xylem water potential in dominant and codominant crown class trees more than a century old were made on six days spread over three growing seasons, accompanied by measurements of soil water potential completed between the predawn and midday sessions of each day. With the exception of a single predawn session, the only one of a total of 12 in which xylem water potentials did not differ among treatments, the potentials in trees of thinned stand subunits were 0.67 MPa higher on average during predawn sessions and 0.71 MPa higher during midday sessions than those in trees of the unthinned treatment. Differences between the cut-to-length and whole-tree treatments were marginal and uncommon, but when they occurred, potentials were higher in the former. Prescribed fire effects on xylem water potential were also uncommon, but when occurring generally indicated lower stress levels in the burned than in the unburned treatment. Soil water potentials largely coincided with those of xylem water, with higher potentials in either the cut-to-length or whole-tree treatments, and usually both, than in the unthinned treatment on each of the six days of measurement. Underburning influences on soil water were rare, but when evident, potentials were higher in the burned than in the unburned treatment by substantial margins. For a majority of the measurement sessions, xylem water potential was found to be negatively correlated with residual basal area but positively correlated with soil water potential. In turn, coarse fragments and organic matter in the soil profile intermittently influenced soil water potential, with the former a negative factor while the latter was positive. Overall, results of this study suggest that substantial ecophysiological advantages can be derived from density management in older, dry site forests, which at minimum are not compromised by subsequent implementation of controlled underburning. 相似文献
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清水河思茅松人工林水土流失监测报告 总被引:1,自引:0,他引:1
通过对清水河思茅松人工林试验区不同造林类型、不同造林年限、不同坡度的泥沙流失量的观测,进行水土流失分析,得出了以下两个重要结论:①坡度为18°的新造林地比坡度为22°新造林地水土流失少35.42%。②2年生林分与1年生林分比较,水土流失大为减少,水土流失减少了95.00%~96.77%,与天然林相比已无多大差别。 相似文献
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在内蒙古大兴安岭根河林业局火烧迹地人工更新造林地内,森林鼠类危害特别严重。为有效防控鼠害,减轻灾害损失,我们在根河林业局火烧迹地内经过实验研究,针对森林鼠兔的习性及生长发育过程中的薄弱环节,提出了以生物防治为主,结合生态控制、天敌保护、人工物理机械防治和化学无公害防治的综合治理对策,有效地解决了鼠患。 相似文献
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Shannon L. Swim Dale W. Johnson Robert M. Fecko Watkins W. Miller 《Journal of Sustainable Forestry》2013,32(8):745-782
Forest thinnings implemented with cut-to-length and whole-tree harvesting systems followed by underburning were evaluated for their effects on individual tree and stand level growth responses in pure, uneven-aged Jeffrey pine (Pinus jeffreyi Grev. & Balf.) accompanied by isolated California white fir (Abies concolor var. lowiana [Gord.] Lemm.). Based on both dimension and volume measures, trees of the unburned whole-tree treatment combination exhibited the greatest individual growth responses. At the stand level, a diminished volume growth response in the whole-tree treatment was especially pronounced in the burned portion, mostly attributable to exaggerated stocking losses, while a superior response in the unburned cut-to-length combination likely reflected not only the absence of detrimental fire impacts but also benefits of on-site slash retention. For stand level biomass, diminished growth in the whole-tree treatment was again evident, with that in the burned portion again most pronounced, while biomass accrual in the unburned cut-to-length treatment combination was generally comparable to that in the unthinned control. Increasingly utilized in forest restoration efforts in the western USA, the responses presented herein to these thinning and burning practices provide natural resource managers insight into potential compromised outcomes when implemented in Jeffrey pine and similar dry site forest types. 相似文献