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1.
以浙江省凤阳山海拔1 300~1 400 m处不同林分类型(阔叶混交林、针阔混交林、杉木林、竹林)为对象,测定不同土层土壤基本理化性质、酶活性及腐殖质质量分数,分析土壤腐殖质特征及影响因素,为凤阳山自然保护区的土壤肥力和可持续经营发展提供理论依据。结果表明:土壤腐殖质质量分数针阔混交林最高,阔叶混交林、竹林、杉木林次之;胡敏酸质量分数针阔混交林最高,杉木林最低;富里酸质量分数针阔混交林最高,竹林最低。除磷酸酶活性随土层加深无统一规律外,4种林分脲酶活性、过氧化氢酶活性及蔗糖酶活性土壤随土层加深皆呈现降低趋势。土壤pH值、土壤密度与土壤腐殖质质量分数、胡敏酸质量分数和富里酸质量分数均呈现显著的负相关;除磷酸酶活性相关性不显著外,土壤脲酶活性、蔗糖酶活性、过氧化氢酶活性、总孔隙度、毛管孔隙、非毛管孔隙与土壤腐殖质质量分数、胡敏酸质量分数和富里酸质量分数均呈现显著的正相关。凤阳山不同林分类型对土壤腐殖质特征的影响较土层深度更显著,土壤理化性质及酶活性与土壤腐殖质质量分数有着密切关系。  相似文献   
2.
为了充实河北雾灵山自然保护区的野生动物资源本底资料,提高监测能力和监测水平,雾灵山保护区自2015年开始将红外相机技术应用到野生动植物的资源调查和管护中。目前应用红外相机技术发现兽类5目10科14种,鸟类4目6科10种,掌握了区内主要物种猪獾(Arctonyx collaris)、狍(Capreolus)和勺鸡(Pucrasia macrolopha)的日活动节律,补充了保护区的本底调查资料,为保护区进一步开展金钱豹(Panthera pardus)、斑羚(Naemorhedus goral)和鸟类多样性等科学研究奠定了基础,为保护区制定关于野生动物资源的相关管护政策提供了科学依据。  相似文献   
3.
王枫 《农学学报》2021,11(9):92-96
经济林良种是经济林产业的“芯片”,是经济林生产优质、高产、高效的物质基础。完善经济林良种推广政策,是实现经济林产业高质量发展的根本保障。通过数据收集和整理,系统梳理全国经济林良种推广现状,指出经济林良种推广中还存在着良种使用率不高,经济林低产低效;部分经济林良种存在超范围推广;良种审定过多,结构性过剩和种植品种过多,对接生产加工不畅等突出问题。进而提出从以种植为目标的良种推广转变为以生产加工等市场需求为导向的良种推广思路。从优化良种供给、加强良种推广的宏观指导、强化科技支撑和宣传培训、实施经济林提质增效工程和充分发挥产业协会、创新联盟的作用等方面给出优化经济林良种推广的政策建议。  相似文献   
4.
Understanding the benefits provided by urban trees is important to justify investment and improve stewardship. Many studies have attempted to quantify the benefits of trees in monetary terms, though fewer have quantified the associated costs of planting and maintaining them. This systematic review examines the methods used to jointly analyse the costs and benefits of trees in the urban landscape, assesses the relative balance of benefits and costs, and attempts to understand the wide variation in economic values assigned in different studies. The benefits most frequently studied are those related to environmental regulation and property values, and the available data show that these usually outweigh the costs. Aesthetic, amenity, and shading benefits have also been shown to provide significant economic benefits, while benefits in terms of water regulation, carbon reduction and air quality are usually more modest. Variation in benefits and costs among studies is attributed largely to differences in the species composition and age structure of urban tree populations, though methodological differences also play a role. Comparison between studies is made difficult owing to differences in spatiotemporal scope, and in the way urban forest composition and demographic structure were reported. The overwhelming majority of studies concern deciduous trees in Northern America, and much less is known about urban forests in other regions, especially in the tropics. Future work should thus seek to fill these knowledge gaps, and standardise research protocols across cities. In light of ambitious goals in many cities to increase tree cover, ongoing advances in valuation methods need to provide a more comprehensive accounting of benefits and costs, and to better integrate economic assessment into the decision-making process.  相似文献   
5.
The fluxes of masses and the nutrients Ca,Mg,K,N,P and S were determined in the litterfall of two adjacent forest ecosystems of Hungarian oak(Quercus frainetto L.)and European beech(Fagus sylvatica L.)in a mountainous area of northeastern Greece in 2010–2015.The foliar litterfall for both species reached about 70%of the total litterfall,and was significantly higher from the other two fractions(woody and rest litterfall).The fluxes of masses and nutrients were compared between ecosystems for each fraction separately.Only one significant statistical difference was found,that of K in the woody litterfall.In addition,the stocks of masses and nutrients were calculated in the forest floors and mineral soils of the two ecosystems.Likewise,the stocks of nutrients in the forest floors and mineral soils were compared between ecosystems.In the L horizon of the forest floors,statistical differences,as a result of species effect,were found for the stocks of Ca and N.In the FH horizons,the masses and all the nutrient stocks differed significantly,as the beech plot had much higher quantities of organic matter and nutrients.These higher quantities were probably due to low soil temperatures(microclimate)and high acidity in the beech plot(species effect)that slowed down decomposition.In the mineral soils,the propagation of random error derived from random errors of the individual soil layers was an important factor in the statistical comparisons.Because of the soil acidity in the beech plot,the stocks of exchangeable base cations were significantly higher in the oak plot,whereas the other nutrient stocks did not differ.  相似文献   
6.
通过建立生态敏感性-生态恢复力-生态压力度(SRP)模型,利用主成分分析法确定指标权重,对南雄丹霞梧桐自然保护区进行生态脆弱性评价。结果表明:1)从生态敏感性角度,研究区高度脆弱和极度脆弱面积分别为756.50 hm2和773.58 hm2,占比之和>50%,主要集中分布于北部和中部,而主要影响要素为土壤侵蚀强度,其次为距水源距离;2)从生态恢复力角度,研究区不脆弱和轻度脆弱面积分别为777.71 hm2和676.73 hm2,占比之和>50%,主要集中分布于西部和西南部,主要影响要素为生物多样性,其次为植被覆盖度;3)从生态压力度角度,研究区不脆弱和轻度脆弱面积分别为551.33 hm2和1 205.12 hm2,占比之和>60%,主要集中分布于西部及东部,而主要影响要素为GDP密度和人口密度;4)研究区整体生态脆弱性较高,中度及以上脆弱性面积之和达到67.72%,主要集中于研究区的中部和北部,其中生态敏感性对生态脆弱性的影响最大,说明研究区整体生态脆弱性较强,应做好生态保护工作。  相似文献   
7.
The newly formed extensive flooded land associated with the Three Gorges Reservoir hold great potentials to provide ecosystem services (ESs) for surrounding cities and communities. Conflicting values and conventional management strategies may complicate and inhibit broad-scale decision-making for this novel ecosystem. Public attitudes are a crucial influence in the way this process plays out. This study was conducted to assess how the reservoir bank is perceived by the general public of Chongqing Municipality in terms of importance of riparian ESs, and preference for corresponding landscape design styles through photo-questionnaire interviewing. Although Chongqing citizens know little of the “ecosystem services” concept, they do recognise riparian environmental and ecological benefits especially the bank protection and pollution interception functions, while benefits of habitats for wildlife and flood attenuation were of less concern. Recreational values were least appreciated, which is inconsistent with other studies. This may be attributed to a wider, intensive environmental education in various social media in today’s China. But publicity has been dominated by toxic air, water and soil pollution control rather than the benefits of nature conservation and personal contact with nature. In line with recognition of ESs, there is quite strong preference for the forested design scenario and particularly vegetation components across the socio-demographic spectrum. Overall, socio-demographic variables have very low explanatory power for the perceptual responses. Our study also revealed misunderstandings around riparian functions and a gap between public expectations and special abiotic and biotic prerequisites in restoring novel ecosystems. Finally, we discuss the relevance of this research to urban novel ecosystems in general, and implications for raising public awareness, engaging appropriate public values in sustainable design and management of such ecosystems.  相似文献   
8.
为解决豚草提取物在林业病虫害防治中的推广与应用问题,以豚草叶片为试验材料,采用温浸-超声波联合提取法提取抑菌活性物质,并开展其对杨树水泡型溃疡病病原菌的室内外抑菌试验。室内抑菌试验表明,粗提物浓度为16 mg/mL时,抑菌率达到73.62%;林间防治试验表明,最小抑菌浓度为 40 mg/mL,抑菌率达到95.14%。通过以上抑菌试验确定豚草粗提物对杨树水泡型溃疡病有较好的抑制效果。  相似文献   
9.
Abstract

The tiger mosquito is a key vector of several human diseases and is considered a public health concern worldwide. The implementation of strategies aimed at maximizing mosquito control without affecting non-target insect groups is of major importance. In a field trial, we tested the efficiency of a natural pyrethrum-based vs. a synthetic pyrethroid-based insecticide in reducing tiger mosquito population and how they affect the diversity of non-target flower-visiting insects in green urban areas. Only the pyrethroid insecticide was effective in reducing mosquito abundance, although its effects disappeared nine days after application. The two adulticides did not significantly affect the diversity of flower-visiting insects, probably because of their large body size and the difference in flying and foraging activity. To effectively control mosquito populations while preventing intoxication of non-target flower-visiting insects, adulticide applications should be applied early in the morning and only on bushes and trees. Results from our small-scale applications cannot be extrapolate when larger areas are treated.  相似文献   
10.
社会林业与五指山的自然保护   总被引:1,自引:0,他引:1  
周燕华  包焱 《热带林业》2001,29(2):73-80
五指山自然保护区是世界上现存地势最高的原始热带雨林之一,是我省目前面积最大的自然保护区,也是海南三大河流的发源地。但由于保护区横跨琼中、通什、保亭三县、市,紧邻保护区还生存着众多贫困的黎、苗族村民。因此,保护区与周边社区的联系是十分紧密的,社区的发展也直接影响到五指山热带天然林的保护。海南省林业局中德海南热带林保护和恢复项目在社会林业与五指山森林的保护上做出了有益的尝试,就在全省来说,也是首次对社会林业与森林保护上进行的探索。五指山地区社会林业的研究,对保护海南热带雨林也有着积极的意义。特对社会林业与五指山的森林保护进行了阐述、分析和设想。  相似文献   
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