On the Relationships between Ground-dwelling Spider (Araneae) Assemblages and Dead Wood in a Northern Sugar Maple Forest

Downed woody material (fallen logs) offers ground-dwelling spiders (Araneae) ideal sites for nesting and foraging, but little is known about what characteristics of dead wood influence spider assemblages. In a maple forest of Forillon National Park, in eastern Québec (Canada), spider assemblages on, adjacent to, and away from fallen logs were compared. We also tested how log type (coniferous vs. deciduous) and decomposition stage influenced spider assemblages. Sampling was done for an intensive four-week period using both litter samples and pitfall traps. A total of 5613 spiders representing 83 species from 16 families was collected. Spiders were affected by the presence of logs, as both species diversity and total number of individuals collected were significantly higher on the log surface compared to the forest floor. Ordination analysis revealed a distinct compositional difference between the spider fauna found on the wood surface compared to the forest floor. Wood type and decomposition stage had few significant effects on spider assemblages, except that less decayed logs supported higher spider diversity than logs in advanced stages of decay. Dead wood is clearly important for generalist predators such as spiders, further supporting the conservation importance of fallen logs in northern forest ecosystems.     

Role of the EXPO ’70 forest project in forest restoration in urban areas

The forest-restoration project of EXPO ’70 Commemorative Park, Japan, is an epoch-making attempt to restore a nature-oriented forest park in an urban area in which large-scale land reclamation had occurred. The objective of this paper is to review the concept, planning, and design, and the outcome so far, and discuss current aspects of creating a core natural habitat in the city of Osaka. Innovative planning policy and design methods have been used for construction of the forest-restoration project of EXPO Park. Unexpected troubles have occurred, however. After approximately 10 years severe effects of poor drainage and soil compaction on the establishment of the forest have been revealed by intensive monitoring. Partial redevelopment and soil-amendment work has therefore been conducted. These improvements seemed to have resulted in “a self-sustaining forest”, the original objective of the planning policy. After approximately 25 years, however, a second intensive monitoring program has revealed that the status of nature restoration is generally favorable in quantity but not in structure of forest communities or biodiversity. The major issues identified are excessive tree density with a single foliage layer caused by the single generation of immature forest stand, and ecological isolation from the source of nature. The EXPO forest is currently in the “Second Generation” stage; this involves management, including artificial gap regeneration, and soil seed bank introduction, with careful monitoring. The project is expected to be an ideal example of a core habitat of nature-oriented forest in urban areas achieved by adaptive management.     

Changes in patch mosaics and vegetation structure of rural forested landscapes under shifting human impacts in South Korea

Landscape change in rural ecosystems is a major global issue because they are an important ecological and socio-cultural resource. The aim of this study was to demonstrate the driving forces behind landscape changes. Changes in the patterns and processes of landscape mosaics and vegetation community in two rural areas (Teokdong-ri, TD and Teokseong-ri, TS) in Korea were studied between 1988 and 2002. Quantitative data of vegetation community, landscape mosaics, and local statistics of the two study areas were analyzed. Agricultural efficiency increased even decreasing household population and the agricultural area. In both areas, as the human dependence on natural resources decreased, the patterns and processes of landscape mosaics and forest structure were changed due to changing human impacts on land use. Owing to the abandonment of forest management for 14 years, the spatial heterogeneity of TD significantly increased more than that of TS. In detrended correspondence analysis ordination, floristic compositions of forest patches of two areas were unevenly located on the ordination axes. Pinus densiflora communities of both areas in 1988 were separately located in 2002 as two directions according to management intensity. The species composition of P. densiflora in one direction of 1988 became similar to those of Quercus forests in 2002. This may be because species composition of P. densiflora has been influenced due to changed habitat environments. Finally, we concluded that the development of forest communities and vegetation succession predicted the spatial pattern of future landscape mosaics and due to the vegetation dynamics of rural ecosystems in Korea.Nomenclature: Miyawaki et al. (1994), Lee (1993), and Lee (1998) for identifying plant species.     

Oomycetes along a 120,000 year temperate rainforest ecosystem development chronosequence

The occurrence of plant-associated oomycetes in natural ecosystems and particularly during long-term ecosystem development is largely unknown. Using DNA sequencing, we investigated the frequency and host relationships of plant-root-associated oomycete communities along a 120 000 y glacial chronosequence, comprising site ages with rapid compositional change (“early succession”; 5–70 y old soil); relatively stable higher-diversity sites (“mature”, 280–12000 y); and ancient, nutrient-limited soils with declining plant biomass and stature (“retrogression”, 60 000, 120 000 y). Plant-associated oomycetes were frequent in early successional sites, occurring in 38–65% of plant roots, but rare (mean 3%) in all older ecosystems. Oomycete OTUs occurred non-randomly with plant host species, and were more frequent on those plant species that declined most strongly in abundance between ecosystem ages. While oomycetes were common in early succession, their absence in older sites suggests a limited role in later stages of ecosystem development.     

Changes in ecosystem services and an analysis of driving factors for China's Natural Forest Conservation Program

China's Natural Forest Conservation Program (NFCP) is aimed at improving the fragile and unstable ecological environment and has become one of the largest ecological restoration programs in the world because of its enormous investment and effects. It is important to work out and strengthen new measures to overcome difficulties to promote more ecosystem services and human well‐being in the NFCP. This study focused on how to evaluate the ecosystem services change brought about by implementing the NFCP. Taking the key state‐owned forest areas in the Northeast and Inner Mongolia as the study area, we provide a basic overview of development and construct an evaluation index system and a distributed calculation method for the NFCP to analyze the implications of the NFCP on ecosystem services combined with multi‐source data coupling. An evaluation index system for NFCP ecosystem services was constructed. The system includes five ecological service functions and 12 evaluation indices. The trade‐off and/or synergistic analysis of ecosystem services were carried out. The regional characteristics and changes in the NFCP ecosystem services were emphasized. Although it has not been implemented for a long time, the NFCP has had a great impact on ecosystem services because it reduces soil and water losses, increases soil fertility, strengthens the forest carbon sink and helped the forest accumulate nutrients and purify the atmosphere. Socioeconomic factors affect the NFCP ecosystem services, such as the implementation area of NFCP, investment amount of NFCP, area ratio of nature reserves, and yield of tree stock volume. Policy drivers of the NFCP, changes in the economic structure and reductions in forest yield are the main factors affecting the change in NFCP ecosystem services. Although the NFCP has positively affected the society, the economy, and the ecological environment, it has also generated some problems, such as the improper management of forest resources, shortage of capital investment, staff transfer, etc. The social and economic problems will be transient with implementation of the NFCP, and the structural changes in forestry and agriculture may eventually benefit the forestry workers and other stakeholders.     

Wood density as a proxy of drought-induced forest dieback in silver fir

Drought-induced dieback is a matter of global concern. It has been widely reported and could compromise the climate warming mitigation potential of forests. That is why we need reliable early-warning proxies to achieve better forecasts of forest dieback and tree death. Tree-ring data can provide some of these needed proxies. Here I propose considering minimum (MND) and maximum (MXD) wood density values as proxies of tree vulnerability against drought. This hypothesis is evaluated in silver fir (Abies alba) forests from the western Spanish Pyrenees showing ongoing dieback processes after the severe 1985 drought. MXD increased in response to warm summer conditions in 1985 whereas MND increased in response to growing-season water deficit in 1986. The average between prior MXD (MXD_t-1) and subsequent MND (MND_t) could be used to detect severe drought impacts and forecast dieback.     

亚热带-温带过渡区秦岭落叶阔叶林幼苗组成及数量动态研究

以秦岭落叶阔叶林25 hm²固定样地的木本植物幼苗为研究对象,于2015 - 2019年对幼苗种类、数量、萌发和死亡情况进行调查,并对幼苗的物种组成、数量及动态特征进行分析。结果显示：5年间调查到的幼苗分属24科42属,共69个物种,累计记录 11 408 株;样地中的树种组成和优势树种组成基本不变,但整体物种数有减少趋势;幼苗数量在年际间和不同物种间有较大差异,17个物种幼苗数量较多,大于100株,其总和占幼苗总量的56.28%,产生新增幼苗的物种有53个,累计增加6280株;死亡幼苗6929株,其中4469株为新生幼苗,占新增幼苗总数的74.14%,新苗的死亡数远远大于旧苗死亡数;幼苗新增和死亡的高峰期大致吻合,出现在每年的5 - 7月。整体看来,秦岭大样地的幼苗数量处于平稳波动状态,物种更新较为稳定。     

Factors involved in the degradation of mangrove forests in Iran: A mixed study for the management of this ecosystem

In Iran, mangroves are located in the south of the country, where they fulfill essential ecosystem functions, but some parts of them have been destroyed for various reasons in recent years so that it seems necessary to have a management plan consistent with the conservation of this ecosystem. But, it needs knowledge of the trend of and reasons for the degradation of these forests. So, the primary idea of this research was to discover the factors involved in the degradation of these forests and how to manage them. So, the research first used the remote sensing technique to determine the rate of their degradation over the last 20 years. Then, using the Delphi technique, 45 factors were identified for the degradation of these forests and they were classified into five categories including climatic and environmental, anthropogenic, socioeconomic, psychological, and policymaking and legal. Finally, the analytic hierarchy process (AHP) was used to rank these factors within two management paradigms of remediability and preventability so that the ecosystem can be soundly managed by classifying these factors. Overall, the results can provide policymakers with new insights into forest management and the policies presented here can contribute to the sustainability of this ecosystem.