隆回县高海拔山区高效生态经济型退耕还林造林模式研究

通过对六种植物配置方式及三种开发模式的对比试验分析，试验出了一种融水土保持效益与经济效益于一体的高效生态经济型造林模式，并探讨了灰毡毛忍冬产量与海拔高度的关系．结果表明：在自然条件恶劣的小沙江高海拔山区，采用金银花(品种为灰毡毛忍冬) 三木药材或其它草本药材，运用景观生态学原理进行设计开发，可获得很好的经济效益与社会效益，并能保持山区的可持续发展．同时还试验出了主栽树种灰毡毛忍冬在海拔1000～1400m之间时经济效益最好．     

我国桉树人工林立地土壤问题研究概况

我国引种桉树。虽已100多年，但研究桉树人工林土壤问题，却只有50多年的历史。这方面的研究，包括桉树人工林土壤本底调查、土壤性质与林木生长的关系、桉树人工林土壤肥力衰退防治、桉树人工林土壤管理、桉树速生丰产的土壤肥力指标、桉树人工林生态系统土壤养分和水分循环等。文章对这方面研究的概况作了简要的综述。     

人为干扰对川西亚高山针叶林土壤物理性质的影响

研究了川西亚高山针叶人工林在几种不同强度人为干扰下林地土壤物理性质。结果表明，随人为干扰强度的增加，土壤中细土（粉粒、粘粒）和大团聚体数量减少，小团聚体和原生土壤颗粒增加；土壤表层孔隙度减小，尤其是大孔隙明显减少；土壤有效水降低，持水供水能力减弱，渗透系数减小。川西亚高山人工针叶林土壤生态功能随人为干扰强度的增加而减弱，建议在最易受人为干扰的造林地区，最好是在造林初期封山育林。图1表5参13     

辽宁东部山区几种主要森林植被类型土壤渗透性能研究

沿辽河水系设置临时标准地 ,对辽宁东部山区具有代表性的油松林、落叶松林、红松林、柞木林、杂木林及灌丛 6种植被类型的土壤水分的入渗性能进行了研究。结果表明 ,辽东山区 6种植被类型下土壤都表现出较强的渗透性能。A层的初始入渗率 (f0 /mm·min- 1) 1 2 .8～ 6 1 .1 ,平均值为 38.7,B层 1 6 .8～4 1 .7,平均值为 2 7.0 ,C层 2 9.2～ 38.2 ,平均值为 2 4 .4 ;A层的稳定入渗率 (fc/mm·min- 1) 2 .6～ 4 .2 ,平均值为 3.5 ,B层 2 .2～ 4 .1 ,平均值为 2 .9,C层 1 .1～ 3.3,平均值为 2 .2 ;A层的饱和导水率 (k10 /mm·min- 1)1 .5 3～ 2 .2 3,平均值为 1 .86 ,B层 0 .77～ 2 .0 5 ,平均值为 1 .2 7,C层 0 .5 0～ 1 .2 8,平均值为 0 .79。不同植被类型下不同土壤发生层次的入渗能力差异显著 :一般地 ,阔叶林下土壤的入渗性能明显好于针叶林 ,榛丛下土壤也表现出很好的渗透性能 ;不同土层入渗性能大小为A层 >B层 >C层。林龄差异在 2个龄级以上时 ,林龄越大 ,土壤初渗性能越好。用Horton方程拟合土壤饱和渗透过程 ,模拟结果与实测结果相近。     

热带山地雨林土壤球囊霉素的分布特征

球囊霉素(GRSP)作为土壤有机碳的重要组分,对土壤质量和土壤碳库有着重要的指示作用。选择我国保存最完好的热带雨林海南尖峰岭为研究对象,通过不同海拔(300、600、900、1200 m)的样品采集,研究了热带山地雨林丛枝菌根(AM)的重要分泌物球囊霉素的空间分布特征,并结合土壤因子,进一步探讨了其分布机制,旨在阐明球囊霉素对热带山地雨林土壤碳库和土壤质量的贡献,丰富丛枝菌根的功能多样性理论基础。结果表明,4个海拔的植物都具有较高的菌根侵染水平,平均为82.92%。不同海拔间,土壤总提取球囊霉素(T-GRSP)和易提取球囊霉素(EE-GRSP)含量具有相同的变化规律,都在海拔1200 m时最高,显著高于其它3个海拔。尖峰岭T-GRSP的质量分数在1.79-3.11 mg·g^-1之间,平均2.205 mg·g^-1;EE-GRSP则为0.75-1.13 mg·g^-1,平均0.904 mg·g^-1。T-GRSP和EE-GRSP占土壤全碳比值的规律在4个海拔也一致,都是在海拔1200 m时最低。在4个海拔中,T-GRSP和EE-GRSP分别占到土壤全碳质量分数的4.33%-8.87%和1.58%-4.12%。对T-GRSP和EE-GRSP的影响因素分析则表明,土壤全碳、全氮和C/N都影响着GRSP的含量;无论是T-GRSP还是EE-GRSP都随着土壤全碳、全氮和C/N的增大而增加;三者对T-GRSP变异的解释率(63.16%、58.94%和36.05%)要远远高于对EE-GRSP变异的解释率(39.59%、32.19%和19.08%)。但土壤pH则仅影响着EE-GRSP的含量变化,全磷则对T-GRSP和EE-GRSP都没有影响。可见,热带雨林土壤中,GRSP含量较高,对土壤碳库具有重要的贡献,且受到土壤全碳和全氮及二者比例的显著影响。     

Disturbance-Mediated Mammal Persistence and Abundance-Area Relationships in Amazonian Forest Fragments

Abstract:  Few researchers have investigated the synergistic effects of tropical forest fragmentation and disturbance on species persistence and abundance. We examined effects of both forest-patch metrics and forest disturbance in determining richness and abundance of midsized to large-bodied mammal species in a highly fragmented Amazonian forest landscape. Twenty-one forest fragments, ranging from 2 to 14,480 ha, and two continuous forest sites were sampled based on sightings, tracks, line-transect censuses, armadillo burrow censuses, and camera trapping. Patch occupancy of 37 species recorded ranged from 4% to all forest sites surveyed. Forest fragment size was the strongest predictor of species persistence, explaining 90% of the variation in species richness. Information-theoretic analysis confirmed that fragment area was the most important explanatory variable for the overall species richness and abundance of mammal species, followed by surface fires, which affected the abundance of seven species. Large mammal species were typically absent from fragments <100 ha, whereas some ubiquitous species were favored by fragmentation, exhibiting hyperabundance in small patches. Our findings highlight the importance of large (>10,000 ha), relatively undisturbed forest patches to maximize persistence and maintain baseline abundances of Neotropical forest mammal species.     

珠江三角洲森林的生物量和生产力研究

利用森林资源清查资料和经过实地校正的相关森林生物量和生产力估算方程,对珠江三角洲森林植被的生物量和生产力进行了研究。结果表明,珠江三角洲森林的生物量为132 404 963 t,总净生产量为26 273 769 t.a-1。区域森林生物量主要分布在珠江三角洲的外围,其中,马尾松林和常绿阔叶林的生物量占区域森林总生物量的52.18%;生态公益林的生物量只到达用材林的48.68%;中幼龄林生物量所占比例很大,总体质量不高,但如果现有森林得到更好地保护和管理,珠江三角洲地区的森林会有较大的发展潜力,并在维护区域生态环境上起着主导作用。     

森林生态系统的水文调节功能及生态学机制研究进展

森林水文调节功能是森林所实现的重要服务功能之一,可是由于森林资源被无节制的开采利用,导致人们不断遭受森林破环所带来的洪旱灾害。因此关于森林生态水文功能研究已成为生态学和水文学的研究重点之一。近年来,国内外对森林水文调节过程及其生态学机制进行了广泛深入的研究,所以文章从森林的水文过程出发,对林冠截留、树干流、凋落物层截留、林地水分涵养和蒸发蒸腾及其影响因子的国内外研究现状进行了归纳分析,研究认为林地各冠层均能够截留降雨,降低雨水动能,从而减少地表径流的产生和对地表的冲击;凋落物层能蓄留水分、抑制蒸散、减缓地表径流;而树干流改变降雨水平空间格局,影响水分入渗以及土壤水源涵养。森林结构复杂,明显改变了降雨分配过程,而森林水文过程及调节功能又受到森林结构的制约,因此定量定性探讨森林生态系统的结构、过程与水文调节功能之间关系,是未来森林生态水文功能研究的重点。     

Conservation of the Marbled Murrelet under the Northwest Forest Plan

Abstract:  The Marbled Murrelet ( Brachyramphus marmoratus ) was listed as threatened in 1992, primarily because of loss of its old-forest nesting habitat. Monitoring conducted over the first 10 years following implementation of the Northwest Forest Plan shows at-sea murrelet populations appear to be stationary, but recruitment is very low and demographic models project a 4–6% annual rate of decline. Monitoring of nesting habitat indicated there were about 1.6 million ha of higher-suitability nesting habitat on all lands at the start of the plan, about half of which occurred on federal lands. Most (88%) of higher-suitability habitat on federal lands was protected within reserves. Over the past 10 years, losses of habitat due primarily to fire have totaled about 2% on federal lands. Losses have been much greater (12%) on nonfederal lands, due primarily to timber harvest. Habitat is expected to accrue within reserves as younger forest matures and attains sufficient diameter to support nesting sites. At-sea estimates of population size are strongly and positively correlated with amounts of adjacent nesting habitat at a broad scale, supporting the idea that amounts of nesting habitat are a primary driver in wide-scale murrelet population distribution. Conditions at sea, however, such as temperature regimes, prey availability, and pollutants, continue to affect murrelet populations. The system of large reserves seems to have achieved the short-term objective of conserving much of the remaining nesting habitat on federal lands. These reserves are also likely to contribute to the long-term objective of creating large, contiguous blocks of nesting habitat. The plan has a primary role in conserving and restoring nesting habitat on federal land but will succeed in this role only if land allocations calling for such protection are in place for many decades.