轿子山飞播示范草场发展现状及对策

针对轿子山飞播示范草场的植被与开发利用现状进行调查研究,通过对轿子山草场进行实地踏勘和测量,对播区内与周边农户进行走访、座谈,对参与飞播和飞播后从事过该草场承包经营、科研、补植补种、复垦、管护的相关人员进行了解,在查阅大量档案资料的基础上,指出了轿子山飞播示范草场成功建设的借鉴意义,以及草场在管理利用中存在的问题,并提出了相应的开发利用建议,旨在为轿子山草场及同类型草场的合理开发利用提供科学依据。     

秀珍菇菌种复壮方法比较

以从秀珍菇(Pleurotus geesteranus)污染菌包中分离得到的3个秀珍菇菌株为出发菌株,采用挑取尖端菌丝、基内菌丝及气生菌丝3种方法进行复壮处理,共获得处理菌株8个。以出发菌株为对照,比较处理菌株的菌落形态、菌丝生长速度及菌丝生物量,并通过出菇实验以及dsRNA检测,对不同复壮方法的复壮效果进行评价。结果表明:尖端菌丝和基内菌丝挑取法能显著提高出发菌株的菌丝生长速度和生物量,可以缩短出菇周期并提高出菇产量;而气生菌丝挑取法则不能对出发菌株进行复壮,其菌丝生物量和出菇产量反而比出发菌株有所降低。     

数字化彩色红外片在编制森林类型图上的利用

主要根据南京紫金山地区１９９６年１∶２万的彩色红外航空像片,采用目视判读的方法,对该地区的森林类型进行划分,小班森林类型判对率的结果为９３．１％,依此可以编制紫金山地区新的森林类型分布图,为紫金山风景区快速制定经营方针和搞好功能区划提供有力帮助,也为数字化彩色红外片制作林业专题图提供基础。     

Forest fragmentation and duration of forest tent caterpillar (Malacosoma disstria Hübner) outbreaks in northern hardwood forests

In northern forests dominated by aspen (Populus spp.), the duration of outbreaks of forest tent caterpillar (Malacosoma disstria Hübner) has been reported to increase with forest fragmentation. This relationship has not been tested in other forest types affected by this widespread native defoliator. From 2002 to 2007, a large-scale outbreak of this insect in the northeastern United States defoliated millions of hectares, with sugar maple (Acer saccharum Marsh.) the primary host. We used digital defoliation maps generated from aerial surveys and national land cover data to assess the effect of fragmentation on outbreak duration in areas of NY, MA, VT, and NH. We found that outbreak duration increased with forest cover and decreased with the forest edge, in opposition to the pattern previously reported for aspen-dominated forests in Canada. This pattern was significant from plot sizes ranging from 100 m to 1000 m in radius. The relationship between FTC and its natural enemies, which was postulated to underlie the effect of fragmentation on outbreaks in aspen forests, may be affected differently in northern hardwood forests, or other factors may be more important in determining outbreak duration in this forest type.     

航空象片成数样点判读取得马尾松面积

本文利用航空象片成数点判读与地面样点(或二类调查固定样地资料)检查纠正判读中错误的方法获得总体内马尾松面积,并结合必要的地面马尾松根根量的调查,取得总体内马尾松根资源的数据,为建立马尾松松根综合利用企业的规模提供必要的依据。     

A novel method for estimating tree dimensions and calculating canopy volume using digital photography

Studies on plant phenology and browse capacity require effective methods to rapidly quantify plant dimensions such as tree height, height of maximum canopy diameter, height of first leaves, maximum canopy diameter, and diameter of trunk(s) at height of first leaves. Here we describe a method for estimating tree dimensions and calculating canopy volume using a measuring staff (for calibration), a digital camera and our VolCalc software. The method requires a photograph be taken of the measuring staff placed next to an object whose measurements are to be determined. The two objects must be adjacent to one another in the photograph. For rapid analysis, multiple photographs of different objects can be taken over a short period of time using the measuring staff. The method is not limited to plants and can be used to determine, for example, browser height, height at which browsers feed, and primate resource abundance. The method has been tested in the field and provides a fast and precise tree dimension parameter estimation option, where sampling time is of the essence. Test results compare well to alternative methods currently utilised, showing improved precision and faster field data collection times, which are important to researchers and ecologists.     

A pre-harvest method for predicting understory light levels created by artificial canopy gaps

A new method for predicting understory light levels around an artificial canopy gap prior to the selective cutting is presented. In two even-aged coppice stands, hemispherical photographs were taken at a height of 1.3 m, and crowns of each canopy stem on the photographs were identified by field observations. To predict light levels after cutting, we used computerized images of the hemispherical photographs, in which we digitally erased all crowns to be cut (named ‘erasing method’). Light levels were calculated by an analyzing program; HEMIPHOT. Light levels predicted by the ‘erasing method’ were compared with that calculated by the ordinary photograph-analyzing method using photographs taken after the actual cutting. The correlations between the two methods were highly significant in the two stands. The ‘erasing method’ is eminently effective for the prediction of understory light levels in an artificial canopy gap.     

陕西飞机播种造林技术浅析

本文总结、分析和调查研究陕西飞播造林,为今后飞播造林设计、施工、成苗成效调查和科学经营管护提供科学依据。     

Effects of topography and management history on natural forest recovery in abandoned forest after clear-cutting in Miyazaki, Japan

We investigated factors limiting the recovery of natural forest in former large-scale conifer plantations abandoned after clear-cutting in southwestern Japan. We analyzed forest recovery status (“recovered” sites covered by evergreen broad-leaved trees, and “unrecovered” sites covered by pioneer community or nonvegetated sites) using aerial photographs and field survey. We applied logistic regression analyses to evaluate the effects of topography, construction of harvesting roads, distance from remnant forest, stand condition before clear-cutting, and prior land-use history on forest recovery. Human factors, i.e., land use and clear-cutting age, were found to affect to forest recovery more than environmental factors such as topography. Harvesting roads had the strongest negative impact on forest recovery. Forest recovery after clear-cutting of young sugi plantations also took longer than after clear-cutting of old sugi plantations or evergreen broad-leaved forests. Furthermore, areas formerly utilized as meadows recovered less successfully than those that had been managed as coppices. The influences of these factors were thought to be promoted by the advance reproduction as the regeneration sources for forest recovery. The influence of stand age before logging suggested an effect of thinning, which might alter the abundance of advanced reproduction in the understory. However, distance from remnant forest appeared to be less important. An influence of topography was also detected, but this could be partly explained by the existence of advance reproduction in the understory in certain topographic positions. Thus, our analysis suggests that regeneration sources originating from advanced reproduction in plantations play a significant role for the recovery of natural forest after clear-cutting.     

森林航空消防的应急预案建设的必要性及原则

森林航空消防是森林防火工作的重要组成部分,因具有反应速度快、机动性强、灵活性高、统观全局的优势,成为现代森林防火工作的发展方向和必然选择。国务院最新颁布的《国家处置森林火灾预案》中首次将森林航空消防列入国家预案中。本文结合国家预案,对森林航空消防预案建设的必要性进行论述,根据森林航空消防预案建设的目标,对其建设原则进行设计,为森林航空消防应急预案的理论建设和架构设计奠定基础。