西双版纳阳春砂仁生产中面临的问题及对策

根据西双版纳阳春砂仁生产中品种退化、低产和与热带雨林生物多样化保护的矛盾等问题,提出了在最适宜区种植砂仁,进行规范化种植、集约化管理,统一加工、打造品牌,提高单产、减少种植面积的对策。     

保护次生林是发展热带雨林的重要途径

海南省有次生林约７００万亩，占全省天然林的８７．５％。次生林可利用的经济价值低，长期以来不为人们所重视。但是从整个热带雨林的发展进程看，次生林能为发展热带雨林创造较佳生境条件。因此，应该把保护次生林作为发展热带雨林的重要途径。     

林口林区次生林改培模式的研究

结合林口林区次生林实际情况,根据不同的林分类型,确定了中龄林、近熟林、成熟林次生林改培理论依据与模式;山杨次生林带状皆伐、间伐改培模式;山杨萌生幼林林隙改培3种次生林改培模式,对恢复高产稳产的针阔混交林分具有重要意义.     

橡胶间种砂仁、咖啡对土壤肥力的影响*

橡胶间种砂仁、咖啡对土壤肥力的影响杨曾奖，郑海水，尹光天，周再知，陈土王，陈康泰关键词橡胶，砂仁，咖啡，胶园间种，土壤肥力地处雷州半岛东海岸的南华农场，在胶园立体种植多层次栽培模式上进行了探索。１９７５年以来，由于逐步发展壳砂仁、咖啡等经济作物，至目...     

勐腊自然保护区砂仁种植现状及管理对策

针对西双版纳勐腊保护区内社区群众种植砂仁的现状,采用地理信息系统(GIS),分户填报砂仁调查表,面上踏察和重点村寨实地调查相结合的方法,对社区居民在保护区内林下种植砂仁的社会经济效益和破坏生物多样性等的问题进行调查分析。结果表明,种植砂仁对社区群众的经济发展有一定的推动作用,同时也对自然保护区的生物多样性产生了破坏作用。藉此提出了加强宣传,发展替代产业,严控种植面积扩大,科学管理现存种植地等对策和建议。     

次生林不同生境模式下套种大叶芹生长状况分析

在大量调查黑龙江省次生林下大叶芹生长环境的基础上,研究了不同立地条件对大叶芹生长的影响,目的是筛选出次生林下大叶芹的高质量种植模式。结果表明：4种林下栽培模式对于大叶芹株高的影响均达到了极显著的水平(p<0.01),不同样地条件对生长中期和生长末期展叶数的影响也达到了极显著水平(p<0.01),在生长中期林下各样地之间的株高排序为：2号>1号>4号>3号,生长后期2号样地株高也是最高,次生林地阳坡栽培模式下大叶芹的株高和展叶树最大、经济效益最好。     

西双版纳勐仑地区不同植被类型鸟类季节变化

2015年1—12月,分春、夏、秋、冬4个季度对勐腊县勐仑镇分布的热带季雨林、石灰山季雨林、热带雨林次生林、人工雨林4种植被类型下的鸟类进行调查。结果表明,从横向看,第一季度和第二季度热带雨林次生林的鸟种类最多,第三季度和第四季度热带季雨林的鸟种类最多;从纵向来看,除热带季雨林为第四季度鸟种类最多外,其余3个植被类型均是第一季度的鸟种类最多。因此,受人为干扰少的植被类型鸟的种类和数量较多,第一季度是鸟类的繁殖季节,鸟类活动较频繁,各植被类型下的鸟类被发现的也最多。     

深圳市城市森林林内景观的美景度评价

在分析深圳市城市森林现状的基础上,运用美景度评价法对城市人工林和天然次生林的林内景观进行景观评价,分析影响森林景观的主要因子,建立各类森林景观美景度模型,探讨主要构景要素与城市森林景观质量的关系。结果表明：深圳市人工林较天然次生林的林内景观质量高,人工林林内景观美景度平均值为0.092,天然次生林为-0.187。影响人工林和天然次生林林内景观质量的主要因子不同,人工林林内景观主要受林下层高度、层间植物丰富度、林木排列方式、枯树倒木、林下层统一度等9个因子影响,其景观模型是 SBE =0.131+0.177x5-0.195x8+0.208x9-0.162x10-0.129x12-0.00008x17+0.113x21+0.007x23-0.571x25;次生林林内景观主要受枯落物、郁闭度、通透距离等因子影响,其景观模型是 SBE =-2.016+0.157x1+0.215x4+1.753x16-0.063x18+0.021x24。     

退化次生林区相思种植分析研究

本研究根据柬埔寨国公省退化次生林区的地理环境和现有植被情况,从造林方式、种苗质量、树种选择、造林管理模式、密度管理与整地方式、幼林抚育管护及采伐年龄确定等方面进行了相思种植的分析研究,结果表明:1)适宜该地种植的主要树种是马占相思及镰刀相思;2)可采用泥袋种子苗进行人工种植;3)在常绿林或裸地、草地上按照3m×2m栽植相思的造林效果最好;4)第一个轮伐期内可不进行施肥,套种旱稻造林可不进行除草抚育措施;5)套种旱稻造林模式效果好;6)相思树的实际生产最适合采伐年龄为6a。该研究能为该省域或相近自然条件下退化次生林区林木种植场的合理开发利用提供科学依据。     

河北省太行山区林药间作模式及适栽药材品种

通过对河北省太行山区气候、森林资源特点和主要生态问题的分析,提出了经济林+药材、天然次生林+药材和灌木林+药材3种林药间作模式,并探讨了其适生药材品种和栽培中应注意的问题。     

橡胶间种砂仁模式下凋落物的特征

文章研究了橡胶＋砂仁胶园间种模式凋落物的年凋落总量和节律、凋落物组成、分解速率、营养元素及养分释放。结果表明：橡胶林下间种砂仁的胶园凋落物具有较多的热带季雨林的特征，总凋落量为７．６５ｔ／ｈｍ２·ａ，与海南岛山地雨林相近；凋落物组分中明显较高的叶含量形成了橡胶＋砂仁模式自己独特的凋落物组分比值；占凋落物总量３９．７％的砂仁枯落物，在胶砂复合生态系统的养分归还上占有十分重要的地位。     

西双版纳自然保护区热带季节雨林破坏后的恢复状况调查

由于热带季节雨林是种植砂仁最适合的场所,因此当地居民大量地将砂仁种植在季节雨林下,对其群落结构及组成造成了严重破坏,导致大量物种的流失。对遭受破坏的群落恢复状况进行调查,结果显示,由于人为活动增加了林下的透光度和生长空间,对幼树和幼苗的生长具有一定的促进作用。只要停止人为破坏活动,经过一定时间,群落仍可得到恢复。     

砂仁种植对西双版纳自然保护区植物物种多样性的影响

砂仁在西双版纳自然保护区广泛种植,给保护区生物多样性带来了一定的危害.通过在原始林和砂仁种植地的热带季节雨林植物群落下设置样地进行调查,掌握了因种植砂仁给季节雨林所造成的物种损失情况以及对群落所带来的负面影响.结合保护区管理工作的实际,提出了解决保护区与当地群众存在的保护与发展之间矛盾的相应管理办法.     

杉木林地套种砂仁提高果实产量的研究

在砂仁由北纬24°37′(长泰)北移到北纬26°34′(南平)获得引种成功的基础上,通过进一步研究试验,在杉木林地套种砂仁,采取田间管理等技术措施的研究,以求达到提高果实产量的目的。     

砂仁北移种群水平的果实产量分析

砂仁由北纬 2 4°37′(长泰 )北移到北纬 2 6°34′(南平 )的种群水平的果实产量分析结果表明 :北移引种砂仁种群密度与生殖株数和花序数成正比。从花发育成果实的过程 ,花序数与成果粒数的定量关系可用函数 y6=82 89- 330 6 1/y2 描述 ;在花期 ,保持单位面积有 4 0株·m-2 植株 ,其中 4 5 %为生殖株 ,壮苗和老苗的生殖株占 6 5 %左右 ,花序数在 2 8穗·m-2以上 ,可作为引种砂仁种群获较高产量的性状指标。     

Modeling the spatial structure of topical forests

The spatial structure of tropical forest stands under different management conditions was modeled as a series of different spatial point processes. Spatial patterns were first assessed by K-function analyses to help choose a point process appropriate for observed patterns. The homogenous Neyman–Scott process accurately described live tree distribution in clear cut areas, where tree patterns tended to be aggregated. Parameters were estimated by minimizing Diggle's modified least squares criterion, and goodness-of-fit was assessed by comparison to confidence envelopes constructed by Monte Carlo simulation. Parameter estimates can be interpreted to help understand the ecological processes influencing re-colonization of disturbed areas. The inhomogeneous Poisson process was investigated for simulating the spatial pattern of ingrowth trees in lower canopy strata. The intensity function of this process was inversely proportional to variables representing canopy density. As assessed by Monte Carlo generation of confidence envelopes, the inhomogeneous Poisson process successfully portrayed the influence of canopy structure on understory plant distribution in most stands. Tree mortality was modeled as a thinning process in which the probability of individual tree mortality was conditional on subject tree attributes and competitive environment. The thinning function took the form of a generalized linear model with a binomial error distribution and logit link function. In most stands, tree neighborhood variables were powerful predictors of mortality, but they were not important predictors in all plots. This suggests that the surrounding forest structure of a subject tree has considerable influence on its morality, but competition is not the sole cause of tree morality in tropical forests.     

西双版纳砂仁叶枯病病原观察

对西双版纳景洪地区阳春砂仁叶枯病病原菌分离鉴定,病原为拟盘多毛孢属Pestalotipssi,国内属首 sp.次报道。     

Use of 3-PG and 3-PGS to simulate forest growth dynamics of Australian tropical rainforests: II. An integrated system for modelling forest growth and scenario assessment within the wet tropics bioregion

Regional model analyses of forest growth are critical for capturing global aspects of tropical rainforest carbon exchange. This research presents the development of a multi-model approach for assessing forest growth and biomass accumulation within the wet tropics bioregion (WTB) based on 10 years of available data and existing model parameter sets. The Tropical Rainforest Growth (TRG) model system employs the 3-PG and 3-PGS models to account for both old-growth rainforest and forest regeneration from seedlings in response to human-induced and natural disturbances. Above-ground biomass (AGB) stocks of the mature forest throughout the WTB for 2000 were estimated to be ∼202 t C/ha. Replacement of areas of old-growth with commercial timber plantations decreased overall AGB stocks to approximately 146 t C/ha. However, plantation carbon accumulation rates were higher than the mature rainforest, representing their potential to accumulate more biomass over a longer analysis time period. As tropical cyclones may significantly alter the carbon stocks of old-growth rainforests, the effect of tropical cyclone Rona on the WTB was assessed. The cyclone had a minimal impact on total AGB stocks within the region, yet these systems are an important factor to be considered in carbon and forest regeneration modelling activities in the tropics. The TRG system is an advanced modelling tool providing a rapid process-based assessment of biomass stocks and accumulation dynamics within Australia's tropical rainforest bioregion and has the potential for application in tropical forest ecosystems at both national and international levels.     

Colonisation of clearfelled coupes by rainforest tree species from mature mixed forest edges, Tasmania, Australia

Mixed forest, containing a eucalypt overstorey and an understorey of rainforest tree species, accounts for approximately 20% (195,000 ha) of Tasmania's wet eucalypt forest. In wood production areas it is typically clearfelled, burnt and then sown with eucalypt seed. This management removes virtually all standing seed sources within the coupe, so that recolonisation of coupes by rainforest tree species depends largely on seed sources located at the coupe edges. We quantified the influence of mature mixed forest edges on rainforest regeneration following clearfelling by modelling the change in the density of the regeneration of the four dominant rainforest tree species (Nothofagus cunninghamii, Atherosperma moschatum, Phyllocladus aspleniifolius and Eucryphia lucida) with increasing distance from forest edge. We also assessed the influence on rainforest tree regeneration of prevailing wind direction, age of regeneration, characteristics of the mature edge vegetation and of the competing regenerating vegetation within the coupe. Distance from edge and age of coupe were highly significant (p < 0.01) effects in each of the species models. We found that the abundance of regeneration declined with increasing distance from edge for all four rainforest tree species, and with the exception of A. moschatum regeneration, increased with coupe age up to the age of 15 years. The abundance of N. cunninghamii and E. lucida, which are species with restricted seed dispersal, declined most steeply with increasing distance from the edge. A. moschatum, which is a species with the potential for long distance seed dispersal by wind, was more abundant than N. cunninghamii and E. lucida at distances greater than 20 m from coupe edges. More than 500 seedlings ha⁻¹ were present at all distances from coupe edge for P. aspleniifolius, reflecting its capacity to germinate after disturbance from soil-stored and bird-dispersed seed. There were no significant differences in seedling density upwind or downwind of coupe edges, although the potential for dense regeneration of N. cunninghamii and E. lucida and for long distance dispersal of A. moschatum appeared to be greatest downwind of edges. Other variables that significantly affected the abundance of regeneration were the height of rainforest tree species in the edge vegetation (N. cunninghamii model), the cover of rainforest tree species in the edge vegetation (A. moschatum model) and the cover of competing eucalypt regeneration within the coupe (P. aspleniifolius model). The proportion of rainforest tree species that regenerated vegetatively was small (3.1%). We concluded that management which maintains mature mixed forest edges, or patches of mature forest within coupes, is likely to result in greater levels of rainforest regeneration and a more rapid shift towards pre-harvest composition following logging. We use our results to demonstrate that variable retention harvesting systems, such as aggregated retention or stripfelling, which reduce the distance to rainforest seed source, would result in a greater abundance of rainforest regeneration over a larger proportion of the coupe than current clearfell, burn and sow silviculture.