Seasonal habitat requirements of Lemon Dove (Aplopelia larvata) in coastal forest: camera-trap surveys of a reclusive species

The modification of natural habitats requires behavioural plasticity, which may be challenging for ‘specialist’ species. Quantifying habitat requirements and behavioural responses of specialists to landscape transformation is thus a priority for baseline data to inform conservation practices. Using camera-trap surveys of the forest-dependent Lemon Dove Aplopelia larvata in conjunction with detailed microhabitat-scale covariates, we assessed habitat use during two periods in the year: autumn–winter and spring–summer (which largely encompassed peak breeding). We used occupancy modelling of forest-structural covariates to produce models of the probability of occupancy and detection of Lemon Doves in patches of the Indian Ocean Coastal Belt Forest of South Africa. The average occupancy and detection probability as indicated by the top-performing models was 0.39 ± 0.08 and 0.26 ± 0.05, respectively, during autumn–winter, and 0.37 ± 0.08 and 0.25 ± 0.04, respectively, during spring–summer. Although occupancy and probability of detection remained relatively constant between seasons, there was seasonal variation in the influence of individual covariates for both measures. The overall trend of positive influences on Lemon Dove occupancy was that of complex and diverse habitat structures and high plant species richness. The specific covariates that influenced occupancy positively during spring–summer may reflect the ecological requirements for nestling provisioning for both dietary needs and an avoidance of potential disturbance. Thus, while Lemon Doves may be less habitat-specific during autumn–winter, conservation management plans for safeguarding the breeding success of the species are advised to ensure adequate protection of large forest patches with complex and diverse interior structures and minimal disturbance.     

黄土高原子午岭林区生态气候效应特征

为揭示黄土高原中心地带子午岭林区生态气候效应特征,利用子午岭林区太白镇气象站气候资料和周边非林地华池县和庆城县气象站同步观测资料,分析月气象要素的年变化曲线和资料序列方差的统计检验结果表明：子午岭林区各月平均气温明显低于周边地区,林地5、7、9月降水量及4-9月降水时间和空气湿度明显多（大）于周边地区,林地盛夏（6-8月）月平均蒸发量明显偏小,表征黄土高原子午岭林地的生态气候效应具有明显的冷凉、湿润和水分利用率高的特征。     

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

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.     

两种热带森林覆盖变化检测方法比较研究

[目的]以热带森林复杂区域为对象,对两种缨帽变换“衍生数据”检测热带森林变化的方法的优劣进行比较.[方法]对两期数据进行缨帽变换,同时结合黑暗对象掩膜与局部直方图阈值提取等方法,获取亮度、绿度、湿度指数组合(MKT)和干扰指数(DI).采用MKT差值(MKT-D)、干扰指数差值(MDI-D)进行变化信息识别,然后,根据植被覆盖与亮度、绿度、湿度之间的变化关系,通过决策树分类提取变化信息,最后,对不同检测结果进行验证与比较分析.[结果]结果显示两种方法都能检测出森林内部的细微变化,但对小图斑变化,MKT-D检测优势明显,且MKT-D的kappa系数为0.763 0,MDI-D的kappa系数为0.655 9,两者相比,MKT-D方法优于MDI-D方法.[结论]MKT能够增强短波红外与近红外波段对森林变化信息的敏感性,有效地消除噪声等非目标信号,突出目标信号,此外,MKT-D为RGB彩色图像,更利于变化信息的目标提取与解译.     

对退耕还林还草有关问题的进一步思考

阐述了“一退双还”政策措施提出的意义和实施情况,提出应进一步明确“一退双还”的目的,从思想和政策上解决重林木轻草灌的倾向,力戒形式主义和表面文章、讲求实绩实效,“以林为主”的绿化方针值得进一步深思和商榷,“一退双还”的责任制和利益机制需进一步完善等一系列问题,值得进一步深入思考和认真解决,以保证“一退双还”和国土绿化工作的持续和健康发展。     

3S技术在贵州省森林资源清查及其评价中的应用

针对目前我国森林资源清查存在的调查周期长,数据现势性差;统计总体内难以同步,数据可比性差;主观影响大,数据可靠性低等问题,在开展贵州省森林资源清查及评价工作中引进了3S技术。结果表明:林业用地的综合判读精度为93.5%,易判读地区的判对率达97%,不易判别读地区的判对率也在90%以上。本次森林资源清查共涉及林业用地面积8749639hm2,总投资约200万元,平均0.23元/hm2,外业工作历时1年,同传统的森林资源清查方法相比,取得了显著的经济效益和社会效益。     

Estimates of forest biomass in the Brazilian Amazon: New allometric equations and adjustments to biomass from wood-volume inventories

Uncertainties in biomass estimates in Amazonian forests result in a broad range of possible magnitude for the emissions of carbon from deforestation and other land-use changes. This paper presents biomass equations developed from trees directly weighed in open forest on fertile soils in the southern Amazon (SA) and allometric equations for bole-volume estimates of trees in both dense and open forests. The equations were used to improve the commonly used biomass models based on large-scale wood-volume inventories carried out in Amazonian forest. The biomass estimates from the SA allometric equation indicate that equations developed in forests on infertile soils in central Amazonia (CA) result in overestimates if applied to trees in the open forests of SA. All aboveground components of 267 trees in open forests of SA were cut and weighed, and the proportion of the biomass stored in the crowns of trees in open forest was found to be higher than in dense forest. In the case of inventoried wood volume, corrections were applied for indentations and hollow trunks and it was determined that no adjustment is needed for the form factor used in the RadamBrasil volume formula. New values are suggested for use in models to convert wood volume to biomass estimates. A biomass map for Brazilian Amazonia was produced from 2702 plots inventoried by the RadamBrasil Project incorporating all corrections for wood density and wood volume and in factors used to add the bole volume of small trees and the crown biomass. Considering all adjustments, the biomass map indicates total biomass of 123.1 Gt (1 Gt = 1 billion tons) dry weight (aboveground + belowground) for originally forested areas in 1976 in the Brazilian Legal Amazon as a whole (102.3 Gt for aboveground only) at the time of the RadamBrasil inventories, which were carried out before intensive deforestation had occurred in the region. Excluded from this estimate are 529,000 km² of forest lacking sufficient RadamBrasil inventory data. After forest losses of 676,000 km² by 2006 – not counting 175,000 km² of this deforested area lacking RadamBrasil data – the estimated dry biomass stock was reduced to 105.4 and 87.6 Gt (aboveground + belowground and only above-ground). Thus, in 2006 the carbon storage in forested areas in Brazilian Amazonia as a whole will be around 51.1 Gt (assuming 1 Mg dry biomass = 0.485 Mg C). Biomass estimates by forest type (aggregated into 12 vegetation classes) are provided for each state in the Brazilian Legal Amazon.     

马尾松,大头茶针阔混交林森林结构的研究

典型选样调查测定,分析马尾松、大头茶常绿针阔混交林的森林特征、种群结构、林分结构、生物量结构及生态功能。结果表明:1.该混交林是亚热带常绿阔叶林前一阶段的过渡性森林类型,在干扰状态下保持其相对的稳定性。2.复层、异龄现象是该混交林的主要特征。建群种充分利用了林地空间营养面积,发挥了林地的生产潜力。叶面积指数达6.86～8.83,林分木材蓄积量达160～222m~3/ha,林分总生物量达114～163t/ha。其中,乔木层生物量达105～154t/ha。光照充足的林下,草本层生物量可达2.5t/ha,对庇护地表起到了最直接、最明显的作用,而调节林冠密度,可控制或促进草本层生物量的增长。3.此种混交林改善了森林立地的蓄水功能和贮水方式。林地土壤最大贮水量达2645～4100t/ha,降水贮存量达565～1256t/ha,林地枯枝落叶层饱和持水量达4589～8702kg/ha。该类型达到了生态与经济效益兼顾,可在我国南方亚热带山地各类工程造林中推广应用。     

Establishment and growth of white spruce on a boreal forest floodplain: Interactions between microclimate and mammalian herbivory

White spruce (Picea glauca (Moench) Voss) is a dominant species in late-successional ecosystems along the Tanana River, interior Alaska, and the most important commercial timber species in these boreal floodplain forests. Whereas white spruce commonly seed in on young terraces in early primary succession, the species does not become a conspicuous component of the vegetation until after 60–80 years. To address what abiotic and/or biotic factors may explain the paucity of spruce in earlier stages of succession, we examined germination and growth of planted white spruce seedlings across an environmental gradient that included variation in soil physico-chemical properties in the presence and absence of mammal browsing. The effect of browsing pressure over the first four years after planting was most noticeable on the older terraces. Likewise, direct effects of hare browsing on spruce seedling mortality were only manifested at the oldest sites. Spruce germination and survival was inversely proportional to soil cation concentrations, which was largely controlled by temperature-driven evapotranspiration. High light intensities and high air temperatures significantly reduced seedling growth, whereas variation in soil moisture only explained a significant amount of variation in seedling survival. Temperatures within the needle clusters on terminal shoots reached values that adversely affect photosynthesis (>32 °C) on multiple occasions over the growing season. We conclude that the direct (temperature) and indirect (soil chemistry) effects of high insolation are major factors constraining spruce performance on early successional terraces, and that these effects can be significantly exacerbated by mammal browsing on associated deciduous vegetation.     

云南省水电开发中森林资源的保护与恢复对策

简要地介绍了云南省水能资源及开发的现状,从林业发展的角度分析了水电站开发对森林资源产生的正、负面影响,并提出水电开发中森林资源的恢复和保护对策.