福建万木林自然保护区古树名木资源初步研究

对建瓯万木林自然保护区森林群落的古树名木资源调查结果表明 ,胸径≥ 80cm的古树名木有 5 6 9株 ,隶属于 15科2 1属 2 9种。笔者对万木林自然保护区古树名木的种类、种群数量、生态分布、树高和胸径等现状进行分析 ,提出了保护该区古树名木的对策     

湿地松在风沙化土地中适应性分析

通过对湿地松在新造林地上的表现的分析，说明湿地松在治沙工程中的作用，建议在工程实施中，重点选择湿地松作为绿化树种。     

试验检测在公路工程中的作用及其运作

本文对公路工程中试验检测的依据、基本理论、部分测试操作技能进行了分析阐述，并对如何在工程实践中切实发挥质检机构的作用进行了探讨。     

如何加强市场经济条件下工程造价管理

本文根据目前工程造价管理的实践，指出了存在的问题，并提出了如何加强市场经济条件下建设工程造价管理的四点具体意见，很有现实意义和指导意义。     

强化木材检验管理是提高经济效益的重要手段

本阐述了森工采运企业强化木材检验工作管理的重要性和必要性，尤其是在国家实施“天保”工程中，企业求发展，就必须在木材检验方面入手，从队伍建设、人员素质提高及经济制约责任等抓起，从而使森工企业走向可持续发展之路。     

现代林业信息网络体系的综合管理

由于林业信息具有种类繁多，信息数量巨大，信息收集复杂，信息需求多样的特点，要求必须通过林业信息网络体系来实现全面系统地搜集，处理、传递，存储和提供大量的字和数字信息，因此，建立林业信息机构主渠道管理制度，以政府统计部门牵头，辅之以林业部门和社会民间团体协调工作，实现林业信息产业化。     

Land use change modeling through an integrated Multi-Layer Perceptron Neural Network and Markov Chain analysis(case study: Arasbaran region,Iran)

Temporal land use/land cover (LULC) change information provides a variety of applications for informed management of land resources. The aim of this study was to detect and predict LULC changes in the Arasbaran region using an integrated Multi-Layer Perceptron Neural Network and Markov Chain analysis. At the first step, multi-temporal Landsat images (1990, 2002 and 2014) were processed using ancillary data and were classified into seven LULC categories of high density forest, low-density forest, agriculture, grassland, barren land, water and urban area. Next, LULC changes were detected for three time profiles, 1990–2002, 2002–2014 and 1990–2014. A 2014 LULC map of the study area was further simulated (for model performance evaluation) applying 1990 and 2002 map layers. In addition, a collection of spatial variables was also used for modeling LULC change processes as driving forces. The actual and simulated 2014 LULC change maps were cross-tabulated and compared to ensure model simulation success and the results indicated an overall accuracy and kappa coefficient of 97.79% and 0.992, respectively. Having the model properly validated, LULC change was predicted up to the year 2025. The results demonstrated that 992 and 1592 ha of high and lowdensity forests were degraded during 1990–2014,respectively, while 422 ha were added to the extent of residential areas with a growth rate of 17.58 ha per year. The developed model predicted a considerable degradation trend for the forest categories through 2025, accounting for 489 and 531 ha of loss for high and low-density forests, respectively. By way of contrast, residential area and farmland categories will increase up to 211 and 427 ha, respectively. The integrated prediction model and customary area data can be used for practical management efforts by simulating vegetation dynamics and future LULC change trajectories.     

兰屿肉桂的栽培及管理

兰屿肉桂(平安树)Cinnamomum kotoense是樟科Laurace ae樟属Cinnamomum常绿观叶树种.其叶子大、四季常青且造形美观,具有很高的观赏价值,其经济效益与发展前景非常好.目前,兰屿肉桂的栽培技术还存在欠缺,栽培管理不到位,导致兰屿肉桂在市场方面供不应求,难于满足市场的需要.文章通过着重介绍兰...     

Recovery of saturated hydraulic conductivity under secondary succession on former pasture in the humid tropics

Landscapes in the humid tropics are undergoing a continuous change in land use. Deforestation is still taking its toll on forested areas, but at the same time more and more secondary forests emerge where formerly agricultural lands and pastures are being abandoned. Regarding soil hydrology, the extent to which secondary succession can recover soil hydrological properties disturbed by antecedent deforestation and pasture use is yet poorly understood. We investigated the effect of secondary succession on saturated hydraulic conductivity (Ks) at two soil depths (0-6 and 6-12 cm) using a space-for-time approach in a landscape mosaic in central Panama. The following four land-use classes were studied: pasture (P), secondary forest of 5-8 years of age (SF5), secondary forest of 12-15 years of age (SF12) and secondary forest of more than 100 years of age (SF100), each replicated altogether four times in different micro-catchments across the study region. The hydrological implications of differences in Ks in response to land-use change with land use, especially regarding overland flow generation, were assessed via comparisons with rainfall intensities.Recovery of Ks could be detected in the 0-6 cm depth after 12 years of secondary succession: P and SF5 held similar Ks values, but differed significantly (α = 0.05) from SF12 and SF100 which in turn were indistinguishable. Variability within the land cover classes was large but, due to sufficient replication in the study, Ks recovery could be detected nonetheless. Ks in the 6-12 cm depth did not show any differences between the land cover classes; only Ks of the uppermost soil layer was affected by land-use changes. Overland flow - as inferred from comparisons of Ks with rainfall intensities - is more likely on P and SF5 sites compared to SF12 and SF100 for the upper sample depth; however, generally low values at the 6-12 cm depth are likely to impede vertical percolation during high rainfall intensities regardless of land use.We conclude that Ks can recover from pasture use under secondary succession up to pre-pasture levels, but the process may take more than 8 years. In order to gain comprehensive understanding of Ks change with land use and its hydrological implications, more studies with detailed land-use histories and combined measurements of Ks, overland flow, precipitation and throughfall are essential.     

Chapter 12. A Wildfire and Emissions Policy Model for the Boise National Forest

Summary

We utilized the Boise National Forest's Hazard/Risk model, along with fire history records and fire behavior models, to estimate the current and anticipated levels of large wildfires and associated greenhouse gas and particulate emissions based on the forest condition and wildfire regime on the BNF. The model indicated that the forests at greatest risk of large, intense wildfires are the dense pondero-sa pine-Douglas-fir forests that make up over 1.1 million acres on the forest. We conclude that without an aggressive treatment program to reduce large areas of contiguous heavy fuel loadings the forest will be burned at an annual average rate of about 7.5% of the remaining at-risk forest. Using recent fire data to develop average patterns of intensity in wildfires within this forest type, we estimate that emissions will average around 1 million tons of carbon (C) per year over the next 20 years as the bulk of the ponderosa pine forests are burned. An aggressive treatment program featuring the removal of fuels where necessary, and prescribed fire as a means of re-introducing fire to these ecosystems, would result in a 30-50 percent reduction in the average annual wildfire experienced in the dense ponderosa pine forests, a 14-35% decrease in the average annual C emissions, and a 10-31% decrease in particulate emissions. We argue that the most effective way to curb emissions is with an aggressive treatment program linked to a landscape-based ecosystem management plan. This would have the effect of breaking up large contiguous landscape patterns so that fires become more patchy and diverse in their environmental impact, resulting in significantly reduced emissions as well as improved landscape diversity.