榆林市黄河沿岸土石山区枣树育苗技术

结合黄河沿岸土石山区干旱缺水,土壤贫瘠特点和育苗地缺乏的实际,总结了该区域比较适应的归圃育苗和根孽育苗两种育苗技术,主要包括苗圃地选择、育苗方法、苗木等级分类及起苗、包装、调运等关键技术。     

郑州黄河风景名胜区文化景观认知与保护研究

郑州黄河风景名胜区经历长期的发展演变,形成具有中原特色的黄河文化,但目前对于其景观资源的认知模式仍以资源导向型为主,忽略了人与自然持续演进过程中产生的文化价值。因此,基于文化景观的视角,通过研究郑州黄河风景区文化价值层积的演变特征,剖析其文化景观物质表象与精神内涵的构成要素,解读其文化景观价值,并提出相应的保护与发展策略,以实现文化景观的可持续发展。     

崆峒山自然保护区鳞翅目昆虫区系研究

经采集、调查、鉴定,崆峒山有昆虫16目,107科,466属,909种。其中有鳞翅目昆虫29科,265属,482种。对鳞翅目昆虫区系分析表明：有古北种398种,占所采鳞翅目种类的82．57％;东洋种47种,占所采鳞翅目种类的9．75％;东洋-古北兼有种11种,占所采鳞翅目种类的2．28％;广布种26种,占所采鳞翅目种类的5-39％;古北种占优势。崆峒山鳞翅目昆虫阴坡种类为阳坡的2．99倍、阴坡昆虫数量为阳坡的2．77倍。崆峒山鳞翅目昆虫1年有1个种数的峰值,出现在7～8月份。     

章古台地区不同密度樟子松人工林衰退情况分析

针对科尔沁沙地东南缘章古台地区的樟子松引种固沙林出现大面积衰退,甚至死亡现象,在该地区樟子松林中选择不同密度的样地进行调查分析。结果表明:樟子松的衰退与林分密度呈正相关;林木的胸径随林分密度的增加而减小,林木的枯死株数、枯梢病感病指数随密度的增加而增加。综合来看,章古台地区樟子松初植密度应控制在1700株hm^-2以下,并应根据生长情况对林木进行疏伐作业,在近熟龄之前将林分密度降至700株hm^-2左右比较适宜。     

榆阳区刀兔大漠海子保护地两栖爬行动物资源调查

2017年9月和2018年6月,采用围栏陷阱法对榆林市刀兔大漠海子保护地的两栖爬行物种多样性进行了调查研究,探讨了湿地面积的变化对两栖爬行动物的威胁。监测历时36d,5组围栏陷阱共捕获2纲2目4科4种66只两栖爬行动物,捕获率为18.3%。通过1973年和2014年刀兔大漠海子面积的变化,发现人类活动对于湿地的侵蚀和淤积起着重要作用,提出了两栖爬行动物栖息地的保护和管理建议。     

东北地区天然林分区简述

从5个方面论述了东北地区的天然林分区与特点。     

Formation of harvest units with genetic algorithms

Operational planning is normally based on stands as the primary unit of treatment. In recent years, interest has been directed towards the use of smaller area units such that the formation of treatment units becomes part of the operational planning. Here, the method of genetic algorithms was used in order to delineate harvesting units in a forest described as a grid of 20 m × 20 m pixels. Remote sensing data and inventory plots were employed to derive pixel estimates of forest variables. Appropriate parameter settings for the algorithm were investigated for two cases that consisted of 26 × 25 pixels. Based on the experience from these tests, the algorithm was employed in forming treatment units in an area encompassing 100 × 100 grid cells, or 400 ha. Due to the size of the problem, a two-stage procedure was suggested. The solutions of the genetic algorithm were compared with a heuristic, a cell removal algorithm, that was proposed in earlier studies of treatment unit formation. The genetic algorithm performed better than the heuristic for all the cases that were tested.     

生态旅游区游客旅游偏好对生态环境的影响——以漓江古东旅游区为例

通过对漓江古东生态旅游区的实地调研结合问卷调查,探讨游客旅游偏好及对环境的影响。结果表明,旅游区内游客以国内中青年为主,游客偏好旅游区清新湿润的空气和清澈的溪流与瀑布,偏好观光旅游和休闲度假旅游。游客旅游偏好对生态环境的影响主要表现在对植物生长环境、空气环境、水环境、景观环境等方面,其中对空气环境和景观环境影响较小,对植物生长环境和水环境影响相对较大。     

Rain forest recovery from dieback,Queensland, Australia

We present a detailed account of a dieback episode in tropical rain forest. The dieback episode took place from 1977 to 1989 within a 0.5 ha long-term demography plot monitored for stem growth and mortality from 1975 to 2005. In total 770 m² of rain forest was affected causing 13 trees >10 cm diameter at breast height (dbh) to die, and others to sicken. The dead trees came from four families, though 14 families were represented in the area. Trees of the family Elaeocarpaceae suffered significantly higher mortality. Larger trees were significantly more likely to die than small trees, but smaller trees were more likely to recover. Recruitment to >10 cm dbh size class after dieback was greater in areas that had been affected, and in 2005 stem density and basal area were higher than in 1977, before the dieback episode started. There were no significant trends in biodiversity change between affected and non-affected parts of the plot. Dieback may have dramatic effects at onset but over the medium term its impact appears to be less serious. Longer term monitoring will permit re-evaluation of this observation in the future.     

丽水生态示范区野生果树资源及开发利用

通过野外调查,初步查明丽水生态示范区野生果树共计28科56属178种,其中包括直接作果品食用、加工成果品制成品食用和作栽培果树育种材料3大类型。文中按果树栽培学的分类方法,将它们划分为仁果类(17种)、核果类(34种)、坚果类(23种)、浆果类(76种)、聚复果类(10种)和柿果及其他(13种)等6类。详细介绍了这些野生果树的种类、性状及其利用方式,并对野生果树资源的利用与保护提出了建议。