Resource Use Dynamics and Land-Cover Change in Ang Nhai Village and Phou Phanang National Reserve Forest, Lao PDR

This study integrated aerial photographs from 1952, 1981, and 1998, and a satellite image from 2000 with oral histories and socioeconomic surveys to assess changes in forest and land cover in Ang Nhai village, Laos. The study documents the history of resource use and changes in household access to resources in the village. Three distinctive trends were observed in terms of forest and land cover—forest degradation, deforestation, and regeneration. Project results suggest that land and forest cover change dynamically under different circumstances. The case study also points out that integration into the market economy can induce intensification of unused lowland areas, while removing pressures from upland areas previously used for supplementing agricultural production. In addition, the creation of a national reserve forest to restrict local access and forest use was an ineffective tool for regulating encroachment and logging activities.     

Hot Spots of Perforated Forest in the Eastern United States

National assessments of forest fragmentation satisfy international biodiversity conventions, but they do not identify specific places where ecological impacts are likely. In this article, we identify geographic concentrations (hot spots) of forest located near holes in otherwise intact forest canopies (perforated forest) in the eastern United States, and we describe the proximate causes in terms of the nonforest land-cover types contained in those hot spots. Perforated forest, defined as a 0.09-ha unit of forest that is located at the center of a 7.29-ha neighborhood containing 60–99% forest with relatively low connectivity, was mapped over the eastern United States by using land-cover maps with roads superimposed. Statistically significant (P < 0.001) hot spots of high perforation rate (perforated area per unit area of forest) were then located by using a spatial scan statistic. Hot spots were widely distributed and covered 20.4% of the total area of the 10 ecological provinces examined, but 50.1% of the total hot-spot area was concentrated in only two provinces. In the central part of the study area, more than 90% of the forest edge in hot spots was attributed to anthropogenic land-cover types, whereas in the northern and southern parts it was more often associated with seminatural land cover such as herbaceous wetlands.     

Effects of payments for ecosystem services on wildlife habitat recovery

Conflicts between local people's livelihoods and conservation have led to many unsuccessful conservation efforts and have stimulated debates on policies that might simultaneously promote sustainable management of protected areas and improve the living conditions of local people. Many government‐sponsored payments‐for‐ecosystem‐services (PES) schemes have been implemented around the world. However, few empirical assessments of their effectiveness have been conducted, and even fewer assessments have directly measured their effects on ecosystem services. We conducted an empirical and spatially explicit assessment of the conservation effectiveness of one of the world's largest PES programs through the use of a long‐term empirical data set, a satellite‐based habitat model, and spatial autoregressive analyses on direct measures of change in an ecosystem service (i.e., the provision of wildlife species habitat). Giant panda (Ailuropoda melanoleuca) habitat improved in Wolong Nature Reserve of China after the implementation of the Natural Forest Conservation Program. The improvement was more pronounced in areas monitored by local residents than those monitored by the local government, but only when a higher payment was provided. Our results suggest that the effectiveness of a PES program depends on who receives the payment and on whether the payment provides sufficient incentives. As engagement of local residents has not been incorporated in many conservation strategies elsewhere in China or around the world, our results also suggest that using an incentive‐based strategy as a complement to command‐and‐control, community‐ and norm‐based strategies may help achieve greater conservation effectiveness and provide a potential solution for the park versus people conflict.     

No evidence of systematic pre-emptive loggings after notifying landowners of their lands’ conservation potential

Landowners can intentionally impair biodiversity values occurring on their land to pre-empt biodiversity protection. This often leads to significant negative effects on biodiversity. We studied whether landowners in Finland engaged in pre-emptive loggings after they were notified that their wooded mires are candidate sites for a mire protection program. After the notification, harvesting rates of the candidate wooded mires were significantly lower compared to harvesting rates of similar but non-candidate wooded mires. Annual and monthly harvesting rates indicated that notifying landowners of the conservation potential did not launch systematic pre-emptive logging behavior. Nevertheless, part of the candidate wooded mires were logged, so some landowners place more weight on other values than the biodiversity ones. Pre-emptive behavior has been observed in other studies suggesting that many country- or system-specific factors such as cultural background or level of compensation can affect landowners’ behavior.Electronic supplementary materialThe online version of this article (10.1007/s13280-020-01354-4) contains supplementary material, which is available to authorized users.     

山林地表慢渗系统处理农村生活污水厂尾水研究

利用山区污水处理厂周边森林植被构建慢速渗滤污水处理系统,用来处理山区农村生活污水厂尾水。结果表明,慢渗系统能够深度净化污水尾水,对COD_(Cr)、NH_3-N、NO_3-N、TN、TP的平均去除率分别为23.8%、40.2%、14.3%、11.3%和23.6%。并且土层越深,COD_(Cr)、TN、TP浓度越低,相应的去除率越高,而NO_3-N、TN去除率则呈降低趋势;山体坡度越大,COD_(Cr)、氨氮浓度有升高趋势,硝态氮、TN、TP有降低趋势;而坡长越大,COD_(Cr)、NH_3-N、NO_3-N、TN浓度有降低趋势,TP有升高趋势。此外,植被类型对水样化学性质有一定影响,竹林更利于COD_(Cr)、NH_3-N、TP浓度的降低,针阔混交林更利于NO_3-N、TN浓度的降低。     

树木水分胁迫和抗旱性机理研究进展

本文从植物对干旱胁迫的反应和抗旱指标、光合作用和蒸腾作用和水分利用效率等研究途径,以及人工采取的抗旱措施等方面阐述了森林植物的抗旱性机理研究现状,并提出了今后研究的重点方向。     

基于无人机多传感吊舱系统的火点实时定位方法

林火定位是林火智能监测设备的核心技术。提出了一种基于激光雷达、红外热像仪及组合惯导多数据融合的火点定位方法。首先设计了一个通用的无人机吊舱系统,并基于ROS框架实现数据采集、数据处理和数据传输等功能;其次提出了一个基于无人机吊舱系统的火点全局定位方案,根据红外热像仪成像特性识别火点,同时将密集点云与红外图像进行数据融合,估计出火点的三维空间位置;然后根据无人机位姿提出了一种基于墨卡托投影的火点全局定位方案,得到了火点的GPS位置。最后通过试验得到了该方案的全局定位精度：在实验中经度最大误差为2.36×10^-5°,纬度最大误差为1.84×10^-5°,高程最大误差为0.926 1 m,为其他林火定位方案提供了技术支持。     

Comparison of forest edge effects on throughfall deposition in different forest types

This study examined the influence of distance to the forest edge, forest type, and time on Cl⁻, SO₄²⁻, NO₃⁻, and NH₄⁺ throughfall deposition in forest edges. The forests were dominated by pedunculate oak, silver birch, or Corsican/Austrian pine, and were situated in two regions of Flanders (Belgium). Along transects, throughfall deposition was monitored at distances of 0-128 m from the forest edge. A repeated-measures analysis demonstrated that time, forest type, and distance to the forest edge significantly influenced throughfall deposition of the ions studied. The effect of distance to the forest edge depended significantly on forest type in the deposition of Cl⁻, SO₄²⁻, and NO₃⁻: the edge effect was significantly greater in pine stands than in deciduous birch and oak stands. This finding supports the possibility of converting pine plantations into oak or birch forests in order to mitigate the input of nitrogen and potentially acidifying deposition.     

Dissipation of four forest-use herbicides at high latitudes

Background, aim, and scope  Large-scale deforestation is occurring in subarctic North America following clearing by salvage logging or insect attack. Numerous shrubs, herbs, and deciduous tree species tend to dominate areas on which stands of white spruce have grown. In the absence of economically advantageous mechanical methods, several herbicides have value in efforts to reforest by planting white spruce. Glyphosate, imazapyr, triclopyr, and hexazinone are all capable of selectively removing many competing species, but there is concern about whether they would degrade naturally or persist owing to the frigid climate. Materials and methods  We established test plots with all four herbicides in upland and river bottom sites at 65°N and 58°N latitudes. The northern site has extremely cold winters, with soils that freeze to a depth of 1–2 m, and precipitation of 275 mm/year. The southern site has heavy rain and snowfall, amounting to 2,250 mm/year evenly distributed. Soil seldom freezes deeply. On each test plot, one of the four herbicides was applied at twice the normal operational use rate to facilitate detection. They were applied at the normal timing, with hexazinone, imazapyr, and triclopyr applied in June and glyphosate applied in fall. Soils were sampled immediately after treatment and those samples used as references for dissipation data gathered over the next 11–14 months from soil 0- to 15- and 15- to 45-cm depths. Results  Dissipation rates did not follow first-order rates because freezing conditions slowed most microbial activity. All products dissipated to close to or below detection limits within the time of the study. Dissipation from vegetation was substantially more rapid and depended on the nature of the plants treated as well as the product used. While soil residues dissipated more slowly than in temperate regions, they did display consistent dissipation patterns during above-freezing conditions and also the influence of microbial activity. Mobility was very limited with all products but hexazinone. Discussion  These products dissipate during summer in high latitudes much as they would in temperate climates. Winter changes are small, but are not unlike some changes reported elsewhere under freezing conditions. Unlike many other studies, soil water did not influence dissipation heavily, but the high latitude and semi-arid climate also did not create severely droughty soils. Residues in plants were much higher than those in soils, but denatured the vegetation quickly, leading to unsuitability for forage in any case. Conclusions  Low toxicity of these products and their metabolites combined with consistent dissipation and low mobility suggest that toxic hazard of their use at high latitudes need not be a matter of serious concern to humans, terrestrial wildlife, or aquatic systems. They are safe for use in management and rehabilitation of boreal forests when used properly. Recommendations and perspectives  Dissipation at rates approaching those in warmer climates offer a hypothesis that microflora native to high latitudes may be adapted to destruction of such molecules at lower temperatures than may be indicated by experiments with microflora adapted to warmer climates. Residues pose no observable risk to wildlife or humans in the area of use when products are applied properly. Electronic supplementary material  The online version of this article (doi:) contains supplementary material, which is available for authorized users.     

Using Spatial Pattern to Quantify Relationship Between Samples, Surroundings, and Populations

The need for accurate carbon budgeting, climate change modelling, and sustainable resource management has lead to an increase in the number of large area forest monitoring programs. Large area forest monitoring programs often utilize field and remotely sensed data sources. Sampling, via field or photo plots, enables the collection of data with the desired level of categorical detail in a timely and efficient manner. When sampling, the aim is to collect representative detailed data enabling the statistical reporting upon the characteristics of larger areas. As a consequence, approaches for investigating how well sample data represent larger areas (i.e., the sample neighbourhood and the population) are desired. Presented in this communication is a quantitative approach for assessing the nature of sampled areas in relation to surrounding areas and the overall population of interest. Classified Landsat data is converted to forest/non-forest categories to provide a consistent and uniform data set over a 130,000 km² study region in central British Columbia, Canada. From this larger study area 322 2 × 2 km photo plots on a 20 × 20 km systematic grid are populated with composition and configuration information for comparison to non-sampled areas. Results indicate that typically, within the study area, the spatial pattern of forest within a photo plot is representative of the forest patterns found within primary and secondary neighbourhoods and over the entire population of the study. These methods have implications for understanding the nature of data used in monitoring programs worldwide. The ability to audit photo and field plot information promotes an increased understanding of the results developed from sampling and provides tools identifying locations of possible bias.