甘肃迭部国有林区生态效益补偿机制的探讨     

唐军 《林业建设》2013,(5):39-42,38

本文从白龙江主要流域的生态现状入手，着重介绍和分析了白龙江流域迭部国有林区生态效益补偿机制的现状和问题，提出了主要的解决办法。  相似文献   

Environmental Change and the Sustainability of European Forests     

《Journal of Sustainable Forestry》2013,32(2-3):165-187

Summary

It is some years now since forest decline was a major public concern in Europe and was one of the principal environmental issues around which international research programs were focused. A number of internationally coordinated activities were initiated in the 1980s and 1990s and have continued until now; these contributed significantly to our current understanding of forestry and to the way in which forestry policies have developed. In short, the concept of sustainable development has had an increasing influence and is now of immeasurable value in forest policy, with sustainable forest management well established as its guiding principle. This sequence of events is examined here. The extent to which understanding has advanced is remarkable; much has changed. Arguably this period gave the first indication of the extent to which forests and ecosystems globally are threatened by environmental change. On the basis of the last 20 years, it is tempting to conclude that we now have an effective institutional framework and have made excellent progress. However, some of the recorded ecosystem responses seem anomalous; there are surprises in system responses, e.g., the linkage between sulphur and nitrogen depositions and forest growth. Even more importantly some specific pollutant problems remain and will intensify, and climate change has become an environmental issue of overwhelming importance.  相似文献   

自然保护区和国有林区野猪在贵州省道真县境内死亡的流行病学调查     

皮泉  刘亚娟  李涛  张人俊  陈能桥 《中国动物检疫》2021,38(4):11-15

2020年2月20日,贵州省道真县生态护林员在其境内的国家级大沙河自然保护区和国有林区发现多具野猪尸体。为弄清野猪死亡原因,防止可能出现的疫情在当地扩散,采用描述性流行病学方法,对本次野猪死亡事件展开调查。截至2020年3月4日,在该县3个镇8个村(社区)10个村民组,共排查发现23具野猪尸体,以体质量偏小的低幼龄野猪居多,约占70%;发现地点分布具有明显的聚集性和方向性;因大部分尸体高度腐败,仅从采集的1份病料中,检出猪圆环病毒核酸阳性,未检出猪瘟、口蹄疫、猪繁殖与呼吸综合征、非洲猪瘟等疫病病原;经排查,未发现野猪尸体附近的村(社区)生猪养殖户饲养的生猪发生异常发病死亡现象。经伽马分布估算,该县平均每天可能出现的死亡野猪数为0.44头(95%CI,0.28~0.64)。综上分析推测,野猪死亡既有经境内公路来往的生猪运输车辆及废弃物传入疫病导致的可能性,也不排除中毒或天气变化等其他因素的可能。由此建议加强公路沿线一带的林区排查,加大跨省公路车辆消毒力度,降低野猪死亡事件带来的潜在风险。  相似文献   

A new galago species for South Africa (Primates: Strepsirhini: Galagidae)     

Fabien Génin  Ayabulela Yokwana  Nokuthula Kom  Sébastien Couette  Thibault Dieuleveut  Stephen D Nash 《African Zoology》2016,51(3):135-143

The primate fauna of South Africa has historically been viewed as comprising three diurnal cercopithecoid taxa – chacma baboons (Papio ursinus), vervet (Chlorocebus pygerythrus) and samango monkeys (Cercopithecus albogularis) – and two nocturnal lorisoid species – the thick-tailed greater galago (Otolemur crassicaudatus) and the southern lesser galago (Galago moholi). Here we report the positive identification of a third galago species within South Africa’s borders: the Mozambique dwarf galago or Grant’s galago, Galagoides granti (Thomas and Wroughton, 1907). The taxon was previously held to be restricted to Mozambique, eastern Zimbabwe, Malawi and Tanzania, but we have also observed it in the sand forest of Tembe Elephant Park and the Tshanini Community Reserve, near the Mozambique border. The species was formerly mistaken for Galago moholi, erroneously (we believe) extending the range of the latter species into northern KwaZulu-Natal. In South Africa the two small galagos are unlikely to have overlapping ranges: Galago moholi prefers dry savanna woodlands, whereas Galagoides granti is apparently confined to dry sand forest. However, both species may coexist with the larger and more widespread Otolemur crassicaudatus, an inhabitant of moist savanna, forest edge and thicket. The true South African ranges of both small galago species need to be ascertained.  相似文献   

Detection of Ecballium elaterium in hedgerow olive orchards using a low-cost uncrewed aerial vehicle and open-source algorithms     

Jorge Torres-Sánchez  Francisco Javier Mesas-Carrascosa  Fernando Pérez-Porras  Francisca López-Granados 《Pest management science》2023,79(2):645-654

BACKGROUND

Ecballium elaterium (common name: squirting cucumber) is an emerging weed problem in hedgerow or superintensive olive groves under no tillage. It colonizes the inter-row area infesting the natural or sown cover crops, and is considered a hard-to-control weed. Research in other woody crops has shown E. elaterium has a patchy distribution, which makes this weed susceptible to design a site-specific control strategy only addressed to E. elaterium patches. Therefore, the aim of this work was to develop a methodology based on the analysis of imagery acquired with an uncrewed aerial vehicle (UAV) to detect and map E. elaterium infestations in hedgerow olive orchards.

RESULTS

The study was conducted in two superintensive olive orchards, and the images were taken using a UAV equipped with an RGB sensor. Flights were conducted on two dates: in May, when there were various weeds infesting the orchard, and in September, when E. elaterium was the only infesting weed. UAV-orthomosaics in the first scenario were classified using random forest models, and the orthomosaics from September with E. elaterium as the only weed, were analyzed using an unsupervised algorithm. In both cases, the overall accuracies were over 0.85, and the producer's accuracies for E. elaterium ranged between 0.74 and 1.00.

CONCLUSION

These results allow the design of a site-specific and efficient herbicide control protocol which would represent a step forward in sustainable weed management. The development of these algorithms in free and open-source software fosters their application in small and medium farms. © 2022 The Authors. Pest Management Science published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.  相似文献   

基于森林资源节约的出版规范改进研究     

刘冠权  李从东  高学锋 《中国农机化》2007,(2):56-58

针对当前我国森林资源和文字规范工作的实际情况,在统计分析了森林资源流向、书刊发行现状的基础上,从节约资源的角度出发,应用工业工程的理论思想和方法对文字的规范标准及纸张节约等相关问题进行分析研究,提出了具有较强操作性和实际意义的改进方法。  相似文献   

Prediction of pine mistletoe infection using remote sensing imaging: A comparison of the artificial neural network model and logistic regression model     

Ayhan Usta  Murat Yilmaz 《Forest Pathology》2023,53(1):e12783

In this study, the prediction of pine mistletoe distribution in Scots pine ecosystems was explored using remote sensing variables to compare the multilayer perceptron (MLP) artificial neural network (ANN) and logistic regression (LR) model performances. For this purpose, 109 sample plots were distinguished in pure Scots pine forests (natural) in the Eastern Black Sea Region of Turkey. Distinguishing mistletoe-infected stands (69) and uninfected stands (40) was performed with field observations. The variables acquired from Landsat 8 (Level 1) images were used as independent variables for independent-sample t-test, MLP ANN and LR models. Remote sensing variables indicated that mistletoe-infected stands were in drier areas with a lower vegetation-leaf area index. Based on the performance results of both models, the sensitivity (SEN), specificity (SPE), positive predictive value (PPV), negative predictive value (NPV) and accuracy of the MLP ANN model were superior to those of the LR model. The prediction percentages (SEN, SPE, PPV and NPV) of mistletoe-infected stands were better than the prediction percentages of uninfected stands. The prediction accuracies of LR and MLP ANN models were 74.3% and 89.6%, respectively. However, all remote sensing variables were included in the prediction equation of the MLP ANN model, while the thermal infrared 1 (TIRS1) variable was included in the LR model. In the MLP ANN model, the TIRS1 variable also had the highest normalized importance (100%). The area under the curve (AUC) value for identifying the mistletoe-infected stands of Scots pine forests used by the MLP ANN model (0.892 ± 0.034) was higher than in the LR model (0.838 ± 0.039), explaining the more accurate predictions obtained from the MLP ANN model. The MLP ANN model showed much better performance than the LR model. The results of this study are expected to make important contributions to the identification of potential mistletoe-infected areas.  相似文献   

半固定沙地樟子松小叶锦鸡儿混交林营造及经营技术研究   总被引：1，自引：0，他引：1  

姚忠宝  曹志伟  张玉柱  高野  卜金祥 《防护林科技》2007,(4):41-42

在对嫩江沙地樟子松和小叶锦鸡儿人工混交林林分状况和生长指标调查的基础上,采用统计分析方法,探讨了混交林主辅林种间的生长消长关系,结果表明:随着林龄的增长,辅助树种小叶锦鸡儿对主栽树种樟子松的生长发育具有抑制作用,樟子松的生长发育进程减慢,应对小叶锦鸡儿林分进行人工干预,以促进樟子松的生长发育。  相似文献   

千岛湖地区森林土壤类型与可持续利用研究   总被引：3，自引：1，他引：2  

许利群  徐高福  朱汤军  姜培坤  岳春雷  宋绪忠  方德好 《防护林科技》2007,(4):47-49

对千岛湖地区森林土壤类型及其分布进行了调查,结果表明:森林土壤有3个土类、5个亚类、10个土属。分布以黄红壤为主,占86.8%;钙质紫砂土次之,占7.8%;侵蚀性红壤占2.7%;石灰岩土占2.5%;黄壤面积最小,仅占0.2%。研究了不同林分类型的土壤理化性质,认为不同湖区林场的天然林土壤养分差异较大,从整个地区角度看各种林型间土壤养分无差异性,但从每个林场单独分析,无论是天然林,还是人工林,阔叶林地养分明显高于针叶林和混交林地。因而,实施针叶林阔叶化改造,对千岛湖地区林地的持续发展,提高其水源涵养、保持水土、景观生态等效益是有益的。  相似文献   

相思树种更新木麻黄防护林对林地土壤化学性质的影响   总被引：8，自引：0，他引：8  

谭芳林  叶功富  王志洁  陆耀龙  陈胜 《防护林科技》2007,(1):1-3

通过对相思树种更新木麻黄防护林对沿海沙地土壤化学性质的分析,结果表明:与木麻黄林分相比,在沿海沙地后沿应用相思树种造林使沙地土壤中水溶性C l-和Na+含量降低,而使表层土壤中的水溶性Ca2+含量升高;相思树种能明显地改善沙地土壤中有效养分的供给,然而,对不同的相思树种来说,其改善程度有所差异;相思树种明显地增加了沿海沙地土壤中全氮和全碳的含量,且增加的量以沙地土壤的表层最为显著。  相似文献