中国交通运输碳排放强度时空交互特征及跃迁机制

采取多种空间分析的方法,对2002～2020年交通运输业碳排放强度的时空交互特征进行剖析,通过得到的时空跃迁类型与面板分位数模型进行嵌套来探究其跃迁机制,最后根据不同的跃迁机制引入地理探测器模型来考察影响交通运输业碳排放强度的不同因素之间的交互作用效应.结果表明: ①中国30个省区的交通运输业碳排放强度整体呈波动下降态势,在空间上的聚集水平也相对稳定.②ESTDA的时空交互特征表明,西北地区和周边邻接空间单位的关系不稳定,变化和波动较大.而东部沿海城市等经济发达地区已经形成了成熟的交通运输网络,因此局部空间格局也相对稳定,但仍有部分地区存在时空竞争性.③交通运输业碳排放强度时空跃迁可分为4类驱动或制约模式（人口-经济-城镇化制约模式;人口-经济-城镇化-设施制约模式;技术-消费-产业驱动模式和技术-产业-规制驱动模式）.大部分省份受低分位制约和高分位驱动两种模式的影响,仅有少部分省份受高分位制约和低分位驱动的作用影响,且绝大多数属于西北或西南地区.④根据得出的交通运输业碳排放强度跃迁机制进一步引入地理探测器模型,注重多因子的协调发展,加强区域间协同治理.     

平原丘陵过渡带土壤有机碳空间分布及环境影响

为定量分析景观过渡带中土壤有机碳空间分布及环境影响,将环境因子纳入空间自回归模型与地理加权回归模型分析比较,并以普通最小二乘回归模型作对照.结果表明:土壤性质指标中,容重及有效铁与土壤有机碳存在极显著相关关系;地形及区位因子中,纬度、高程、坡度、粗糙度等稳定性因素与土壤有机碳存在极显著相关关系;土壤有机碳的局部集聚性多发生在核心景观过渡带;空间回归模型的拟合优度均优于普通最小二乘回归模型,估计值的空间自相关变化趋势与实测值一致,残差的空间模式显著减弱;能够灵活调整权函数与带宽的地理加权回归模型能够更好地分析土壤有机碳的空间变异.模型评价方面,GWR-1和GWR-2的残差平方和较OLS分别降低了20.717%和8.799%; SLM、SEM、GWR-1、GWR-2的AIC值较OLS分别减小了5.108、5.391、19.887和11.751.除本身存在的空间自相关外,模型中土壤性质指标及环境因子能大幅解释土壤有机碳的异质性.本研究引入辅助变量,运用空间回归模型分析了平原丘陵过渡带土壤有机碳的空间变异,可为生态恢复、环境变化指示及研究区典型柑橘区的区划提供依据.     

The political ecology of Yukon forestry: managing the forest as if people mattered

Over the past several decades a growing interest has emerged in the relationship between forest dependent communities and their use of non-timber forest resources (NTFR—i.e. berries, roots, barks). Motivated in large part by international concerns over the loss of biological and cultural diversity, efforts are now being made to conserve the world's remaining forests by repositioning NTFR to the forefront of the forest management process. Together with the Little Salmon Carmacks First Nation, we have undertaken an assessment that: 1) addresses the role of NTFR in fulfilling basic human necessities and well-being of community members, and 2) identifies the perceptual differences that exist among First Nation and non-First Nation community members regarding the security and future availability of forest resources. Based on our findings, we argue that if the true value of the forest is to be understood, and thus sustained, those involved in management must consider the full array of products and services the forest provides. Thus the conventional and over-simplified view that the forest is to provide primarily for commercial timber must be challenged in light of the multiplicity of values community members gain from forest use.     

特长隧道环境下驾驶人注视转移特性研究

为了研究不同经验驾驶人在高速公路特长隧道环境下的注视转移特性,在高速公路特长隧道中开展实车实验,利用 iView X HED型眼动仪采集了32名不同经验驾驶人的眼动数据。运用动态聚类方法,对驾驶人注视区域进行划分,分析了职业与非职业驾驶员在高速公路隧道不同段与普通路段的注视转移规律与注意力分配特性。结果表明:相较于非职业驾驶人,职业驾驶员具有较强的注视前瞻性,且在隧道的不同段主要注视的区域因行车环境不同变化较小;驾驶人对同一目标需要重复注视才能提取足够的信息,且当行车环境复杂度增加或驾驶员驾驶经验不足时,重复注视概率增加;驾驶人在不同路段行车时,主要通过注视中间区域获取信息;行车环境与驾驶经验对驾驶人在中间近处、左侧区域及内后视镜区域的注视平稳分布存在显著的交互作用。     

Modis reflectance and active fire data for burn mapping and assessment at regional level

This paper presents an algorithm for rapid and accurate burn mapping that is applied here to the forest fires occurred in Galicia (northwest Spain) in August 2006, when nearly 930 km² were almost entirely burned over the course of eight days. The algorithm synergistically combines remotely-sensed reflectance and active fire data as measured by the MODIS (MODerate resolution Imaging Spectrometer) sensor on board Terra and Aqua NASA (National Aeronautics and Space Administration) satellites. Burned area data collected from this work was compared to official fires statistics from the Spanish Ministry of Environment and to perimeters that were derived using a high spatial resolution satellite image. In a later step, burn patches area analyzed using information from the National Forest Map (1:50,000) and some Geographical Information Systems (GIS) tools.     

Modelling forest management within a global vegetation model—Part 1: Model structure and general behaviour

This article describes a new forest management module (FMM) that explicitly simulates forest stand growth and management within a process-based global vegetation model (GVM) called ORCHIDEE. The net primary productivity simulated by ORCHIDEE is used as an input to the FMM. The FMM then calculates stand and management characteristics such as stand density, tree size distribution, tree growth, the timing and intensity of thinnings and clear-cuts, wood extraction and litter generated after thinning. Some of these variables are then fed back to ORCHIDEE. These computations are made possible with a distribution-based modelling of individual tree size. The model derives natural mortality from the relative density index (rdi), a competition index based on tree size and stand density. Based on the common forestry management principle of avoiding natural mortality, a set of rules is defined to calculate the recurrent intensity and frequency of forestry operations during the stand lifetime. The new-coupled model is called ORCHIDEE-FM (forest management).The general behaviour of ORCHIDEE-FM is analysed for a broadleaf forest in north-eastern France. Flux simulation throughout a forest rotation compare well with the literature values, both in absolute values and dynamics.Results from ORCHIDEE-FM highlight the impact of forest management on ecosystem C-cycling, both in terms of carbon fluxes and stocks. In particular, the average net ecosystem productivity (NEP) of 225 gC m⁻² year⁻¹ is close to the biome average of 311 gC m⁻² year⁻¹. The NEP of the “unmanaged” case is 40% lower, leading us to conclude that management explains 40% of the cumulated carbon sink over 150 years. A sensitivity analysis reveals 4 major avenues for improvement: a better determination of initial conditions, an improved allocation scheme to explain age-related decline in productivity, and an increased specificity of both the self-thinning curve and the biomass-diameter allometry.     

Biogeochemical model (BGC-ES) and its basin-level application for evaluating ecosystem services under forest management practices

It is important for humans to live in harmony with ecosystems. Evaluation of ecosystem services (ES) may be helpful in achieving this objective. In Japan, forest ecosystems need to be re-evaluated to prevent their degradation due to lack of forest management.In order to evaluate the effects of forest management on forest ES, we developed a process-based biogeochemical model to estimate water, carbon, and nitrogen cycles in forest ecosystems (BGC-ES). This model consists of four submodels: biomass, water cycle, carbon-nitrogen (CN) cycles, and forest management. The biomass submodel can calculate growth of forest biomass under forest managements.Several parameters of the model were calibrated using data from observations of evapotranspiration flux and quality of stream flow in forests. The model results were compared with observations of runoff water from a dam catchment site and with carbon flux observations.Our model was coupled with a basin-level GIS database of forests. Evaluations under various forest management scenarios were carried out for forests in a basin contained in the Ise Bay basin (Chubu region, Japan), where plantations (artificial forests) seemed to have degraded from poor forest management.Comparing our simulation results with those of forests without management in the basin, we found that the amounts of absorbed carbon and runoff were larger in managed forests. In addition, the volume of harvested timber was larger and its quality (diameter) was better in managed forests. Changes of ES within the various scenarios were estimated for their economic value and were compared with the cost of forest management.     

Estimating the spatio-temporal risk of disease epidemics using a bioclimatic niche model

There are presently few tools available for estimating epidemic risks from forest pathogens, and hence informing pro-active disease management. In this study we demonstrated that a bioclimatic niche model can be used to examine questions of epidemic risk in temperate eucalypt plantations. The bioclimatic niche model, CLIMEX, was used to identify regional variation in climate suitability for Mycosphaerella leaf disease (MLD), a major cause of foliage damage in temperate eucalypt plantations around the world. Using historical observations of MLD damage, we were able to convert the relative score of climatic suitability generated by CLIMEX into a severity ranking ranging from low to high, providing for the first time a direct link between risk and impact, and allowing us to explore disease severity in a way meaningful to forest managers. We determined that the ‘Compare Years’ function in CLIMEX could be used for site-specific risk assessment to identify severity, frequency and seasonality of MLD epidemics. We explored appropriate scales of risk assessment for forest managers. Applying the CLIMEX model of MLD using a 0.25° or coarser grid size to areas of sharp topographic relief frequently misrepresented the risk posed by MLD, because considerable variation occurred between individual forest sites encompassed within a single grid cell. This highlighted the need for site-specific risk assessment to address many questions pertinent to managing risk in plantations.     

云南地区种子植物区系属的多度及区系过渡性的空间分布格局

植物区系地理分布格局的研究有助于更好地理解植物区系的起源、迁移和分化。研究利用覆盖云南地区全境的植物区系分布信息,探讨了云南地区植物区系属的多度及区系过渡性的地理分布格局。结果表明,所有热带区系属的多度均随着纬度升高呈递减趋势;大多数温带区系属的多度随着纬度的升高呈递增趋势。中亚分布（T13）属的多度的高值主要出现在滇西北地区,尤其是在金沙江、澜沧江和怒江的上游地区,但在其它地区十分少见。地中海、西亚至中亚分布（T12）属的多度的高值也出现在滇西北地区,但在其它地区无明显空间分布规律;中国特有分布（T15）属在滇西北地区最为丰富,其次是滇东南地区,大致以“田中线”为界,界线以西地区的中国植物特有属的多度明显低于界线以东地区。从南到北,植物区系过渡性基本上呈单调递增格局,这一格局的形成可能与区系成分的迁移和地形格局有关。大理州以南的低海拔地区,热带区系成分占据主导地位,并占据了云南大部分的土地面积,这在一定程度上证实了云南地区总体上是一个“热带山原”的假说。本研究与其它研究的不同可能源于与源数据和取样尺度的差异。     

基于层次分析法的森林火险区划 —以徂徕山林场为例

森林火险区划是林火管理的基础。利用层次分析法将影响森林火险的静态因子评判指标分成三个层次,根据专业知识确定各因子权重,充分利用现有的可燃物和地形数据信息,以徂徕山林场为例进行了森林火险区划。区划结果表明,徂徕山林场大部分地区的火险为中低火险,高和极高火险区域面积分别占林场总面积的11.6%和3.1%。本研究为林场尺度上开展科学的火险区划提供技术参考。