Tree-ring:a suitable implement for spatial and temporal fire distribution analysis in savanna woodla

来源 :Journal of Forestry Research | 被引量 : 0次 | 上传用户:wende198
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
Based on 120 stem discs collected during3 months of fieldwork along a 12 km route,the history of fires in the Wari Maro Forest(09 1000 N–02 1000E) over the past century in savanna woodland and dry forest was reconstituted.Three major ecological areas are characterized:one highly burnt zone located between two relative less burnt areas.By analyzing tree rings,246 fire scars were identified.The scars were caused by 51 fire years,occurring at a mean interval of 2.23 years.From 1890 to1965,only 6 years with fires were recorded from sampled trees.Since 1966,no year has passed without fire.The fire frequency point scale reached 14 years.This was the case of Burkea africana,which has been identified as a species tolerant to fire and could be planted to create a natural firewall.In contrast,Anogeissus leiocarpa is highly sensitive to fire,and in a dry forest ecosystem that burns seasonally,it requires a special conservation plan.Two new concepts are described:the rebarking of trees after fire and Mean Kilometer Fire Interval.The first concept was tested with Daniellia oliveri(Rolfe) Hutch & Dalz trees,and the second concept was used to evaluate spatial fire distribution.We demonstrate that savanna woodland and dry forest were subject to a degradation process caused by destructive fires related to vegetation cover clearance and illegal logging. Based on 120 long films collected during 3 months of fieldwork along a 12 km route, the history of fires in the Wari Maro Forest (09 1000 N-02 1000E) over the past century in savanna woodland and dry forest was rehabilitated. Three major ecological areas are characterized: one highly burnt zone located between two relative less burnt areas. By analyzing tree rings, 246 fire scars were identified. The scars were caused by 51 fire years, occurring at a mean interval of 2.23 years. Flash 1890 to 1965, only 6 years with fires were recorded from sampled trees. Since 1966, no year has passed without fire. The fire frequency point scale reached 14 years. This was the case of Burkea africana, which has been identified as a species tolerant to fire and could be planted. to create a natural firewall. In contrast, Anogeissus leiocarpa is highly sensitive to fire, and in a dry forest ecosystem that burns seasonally, it requires a special conservation plan. Two new concepts are described: the rebarking of trees after fir e and Mean Kilometer Fire Interval. first concept was tested with Daniellia oliveri (Rolfe) Hutch & Dalz trees, and the second concept was used to evaluate spatial fire distribution .We demonstrate that savanna woodland and dry forest were subject to a degradation process caused by destructive fires related to vegetation cover clearance and illegal logging.
其他文献
光纤激光器具有转换效率高、光束质量好、结构紧凑、维护方便等优点,在科学研究、工业加工、国防军事等领域具有广泛的应用前景。超荧光(放大的自发辐射,ASE)光源具有光谱覆
我国改革开放的进程逐渐加快,经济发展和社会进步的步伐都上了一个新的台阶,人们的消费理念和消费意识都发生了翻天覆地的变化,在这个大背景下,高校高职高专的教育也就不像过
为了进一步减小平面EMI滤波器的体积、缩短制作周期、降低开模成本、提高功率密度及解决复杂模型制作困难等问题,提出一种利用3D打印来实现平面磁集成EMI滤波器的技术。提出
在八届人大五次会议期间,省委书记田成平结合黄河、长江源头的水土流失问题指出,在国民经济发展过程中,要加强环境与资源保护,走可持续发展之路.黄河水近年在中游、下游多次
党中央、国务院明确指出,实现“九五”和2010年的奋斗目标,关键是实现两个具有全局意义的根本性转变。这次全国水利经济工作会议的主要任务就是贯彻落实《建议》和《纲要》
模拟技术是指在系统模型上进行试验的技术。对于各种类型的系统有各种不同的模拟手段和模拟方法。根据输入变量和输出变量是否确定,模拟技术可划分为随机型和确定型两种类型。
针对扫描干涉光刻机干涉图形相位锁定需求,提出并设计了干涉图形相位锁定系统。该系统采用零差相位干涉仪实现干涉图形相位漂移的高速高精测量,采用声光调制器以高速高精移频
介绍了激光回馈的概念及其两种主要的理论研究模型:三镜腔模型和注入锁定模型。激光回馈干涉仪相位灵敏度与传统双光束干涉仪相当,且具有结构简单、紧凑、易准直、对激光器无
采用热丝化学气相沉积(HWCVD)方法沉积本征非晶硅薄膜,研究了热丝电流对薄膜结构及其钝化单晶硅片效果的影响。采用光谱型椭偏仪分析了非晶硅薄膜的介电常数虚部ε2和薄膜空
编者按:’97三峡工程技术国际研讨会于11月26~28日在三峡坝区召开,来自12个国家和国内的专家共200多人参加会议,就三峡工程二期围堰防渗墙施工技术、二期工程混凝土浇筑技术和大