Regeneration patterns of key pine species in a mixed-pine forest indicate a positive effect of varia

来源 :森林生态系统(英文版) | 被引量 : 0次 | 上传用户:sfx158158
下载到本地 , 更方便阅读
声明 : 本文档内容版权归属内容提供方 , 如果您对本文有版权争议 , 可与客服联系进行内容授权或下架
论文部分内容阅读
Background: Many fire-dependent forests have experienced significant declines in species, structural, and functional diversity. These changes are attributed in part to traditional management approaches that were dominated by even-aged regeneration methods such as clearcutting. Variable retention harvesting (VRH) is an ecologically based forestry practice that involves retention of some mature overstory trees and other biological structures in the postharvest stand to emulate the effects of natural disturbance events. In this study, we examined the effect of a VRH treatment on recruitment of historically dominant pine species and understory vegetation two-and six years after its implementation in a naturally regenerated mixed pine forest in the Upper Peninsula of Michigan, USA.Results: We found greater regeneration of red pine (Pinus resinosa L.) and eastern white pine (Pinus strobus L.) in VRH stands compared to the unharvested controls. Although red pine recruitment was very low during the first 2 years, both species increased significantly from year two to year six. Recruitment responses for the two species did not differ significantly between the aggregated and dispersed retention treatments. We also found high recruitment of deciduous tree species, consisting primarily of sprouts, and red pine exhibited a negative correlation with these sprouts. Treatment, time, and the interaction of treatment and time were significant factors in red pine recruitment. Time had a strong effect on the understory vegetation, with significant decreases in shrubs and ferns over time.Conclusions: The results suggest that VRH enhanced recruitment of red pine and eastern white pine and that this recruitment increased with time. We identify competition from sprouts and unfavorable seedbed conditions as the main factors that limited recruitment of red pine during the first 2 years. To reduce competing vegetation and improve seedbed conditions, we suggest following the VRH with a prescribed fire, mechanically removing sprouts,and implementing herbicide treatments. At a time when changes in global climate exacerbates the effects of traditional drivers of forest degradation, and with the need to maintain biodiversity, new ecologically based forest practices such VRH have the potential to facilitate regeneration of native trees and enhance the resilience of many fire-dependent forests.
其他文献
  本文简述了“中国农资连锁配送网络工程”背景情况,介绍了该工程的发展经验及思路:1.以资本为纽带促进农资系统联合发展;2.以科学管理提升农资网络运行质量;3.完善社会化服务
为了提高对于乳腺癌差异基因筛选的准确率,从分子层面出发,结合拷贝数与基因表达两方面特征,分析了乳腺癌差异表达基因,研究了乳腺癌的发病机制,为乳腺癌的诊疗提供了新的研
低速拒绝服务攻击对于域间路由系统造成威胁,已有失效恢复算法未能有效解决恢复拓扑计算的时间复杂度高和节点聚合控制等问题,为此,提出一种基于度约束最小生成树的失效恢复
  农作物种植结构及种植面积的变化是影响化肥需求的基础性因素。本文在对中国各地区不同农作物种植面积、各农作物单位面积上不同化肥品种施用量变化分析的基础上,对中国各
  本文概述了世界钾盐资源的状况,分析了国内外的钾盐的生产供应情况、消费现状、需求预测及供应平衡,并针对中国钾盐行业发展存在的资源不足、管理和营运体制不够完善、产品
本文对茉莉花茶香气品质与茉莉花香气的关系、茉莉花香气合成途径及影响茉莉花香气释放的环境因素进行了简要综述 ,并分析了茉莉花释香的可能途径。 In this paper, the rel
  本文概述了近年来农业生产资料价格变动总体情况,分析了主要农业生产资料价格变动情况及其原因,并进一步探讨了农业生产资料价格变动对农业生产和农民收入的影响:1.农资价格
  本文简述了粮食供应与需求的现状,详细介绍了大豆、玉米、稻谷、小麦等作物生产中的肥料问题及培肥土壤对创高产的重要性。结果表明:中国粮食生产中的肥料问题,不是化肥数量
  本文阐述了河南心连心化肥公司对化肥市场的基本认识,主要包括:1.尿素行业的未来将是一个供应增长较快,需求增长趋缓的过程。2.从企业竞争发展到产品链竞争。3.产业布局转移
  农村人口养老目前主要是家庭、个人积累、自然资源如耕地、山林等以及社会和国家救济等多种屏障,80年代中国人口由于计划生育、医疗水平的提高、经济的快速发展以及迁移等
会议