A comparison of three models of 137Cs transfer in forest ecosystems.

The predictions of three models of 137Cs transfer in forest ecosystems (FOA, LOGNAT and FORESTLAND) were compared. The scenario for the model-model comparison consisted of an acute dry deposition of 137Cs over a coniferous forest. The model predictions were subsequently compared (model-data comparison) with values derived from experimental data measured in forests of the Bryansk region in Russia that were contaminated by the Chernobyl accident and that have similar characteristics to the forests described in the scenario. The predictions of radiocaesium levels in the litter-soil layer, berries, needles, wood, whole tree and moose made with the models were in relatively good agreement with each other (within a factor of 1.4-2.9). The best agreement was observed for berries and moose and the worst for wood. There was also good agreement between the model predictions for the same variables and the experimental data (within a factor of 1.2 3.2). In this case, the best agreement was observed for the litter-soil layer and the worst for wood and the whole tree. Overall, at least for the studied scenario and for the first 10 years after deposition, any of the models can be used if the final aim is to estimate average concentrations in different forest components. The agreement between the model predictions worsens with time and there were differences in the form of the time dependencies predicted by the models, especially for wood. This may lead to larger differences between the model predictions and the experimental data for times beyond the period for which data were available for comparison (10 years after the deposition).     

The State of Populations and Selective Hunting of Game Ungulates in the Middle Urals

The population dynamics of moose, wild boar, and roe deer in the Middle Urals and changes in the proportion of females among the animals taken by hunters were analyzed. For all the three species, a tendency toward selective hunting for females was revealed. In this situation, the proportion of females in a population decreases with time, and its reproductive potential is impaired.     

Land-cover changes in and around a National Park in a mountain landscape in the Pyrenees

The current state of Mediterranean mountain areas has been driven by two main factors: intense traditional human activity and the dynamics of the ecosystem itself. In this study, we examine land-cover changes in a National Park in the Pyrenees mountains (NE Iberian Peninsula), which was designated a protected area 55 years ago. First, we have analyzed spatio-temporal changes in land-cover pattern and forest dynamics from 1957 to 2005. During this period, land-cover dynamics consisted of two main processes: (i) expansion of the forest area and (ii) increasing cover of forests already present in 1957. To analyze the role of the conservation level of the park, we have also compared the results obtained within the park with those of unprotected, peripheral areas. In the two areas with different protection level, dense forests increased throughout the period because of the reduction in forestry activities. The peripheral area showed a higher rate of forest-cover change from 1957 to 2005 compared to the National Park. This higher increase in forest cover in the peripheral area could be related to a higher proportion in the National Park of screes and rocky areas and to the decline and transformation of forest activities in these peripheral, lower elevation areas.     

Accurate modeling of harvesting is key for projecting future forest dynamics: a case study in the Slovenian mountains

Maintaining the provision of multiple forest ecosystem services requires to take into consideration forest sensitivity and adaptability to a changing environment. In this context, dynamic models are indispensable to assess the combined effects of management and climate change on forest dynamics. We evaluated the importance of implementing different approaches for simulating forest management in the climate-sensitive gap model ForClim and compared its outputs with forest inventory data at multiple sites across the European Alps. The model was then used to study forest dynamics in representative silver fir–European beech stands in the Dinaric Mountains (Slovenia) under current management and different climate scenarios. On average, ForClim accurately predicted the development of basal area and stem numbers, but the type of harvesting algorithm used and the information for stand initialization are key elements that must be defined carefully. Empirical harvesting functions that rigorously impose the number and size of stems to remove fail to reproduce stand dynamics when growth is just slightly under- or overestimated, and thus should be substituted by analytical thinning algorithms that are based on stochastic distribution functions. Long-term simulations revealed that both management and climate change negatively impact conifer growth and regeneration. Under current climate, most of the simulated stands were dominated by European beech at the end of the simulation (i.e., 2150 AD), due to the decline of silver fir and Norway spruce caused mainly by harvesting. This trend was amplified under climate change as growth of European beech was favored by higher temperatures, in contrast to drought-induced growth reductions in both conifers. This forest development scenario is highly undesired by local managers who aim at preserving conifers with high economic value. Overall, our results suggest that maintaining a considerable share of conifers in these forests may not be feasible under climate change, especially at lower elevations where foresters should consider alternative management strategies.     

Dynamics and determinants of land change in India: integrating satellite data with village socioeconomics

We examine the dynamics and spatial determinants of land change in India by integrating decadal land cover maps (1985–1995–2005) from a wall-to-wall analysis of Landsat images with spatiotemporal socioeconomic database for ~630,000 villages in India. We reinforce our results through collective evidence from synthesis of 102 case studies that incorporate field knowledge of the causes of land change in India. We focus on cropland–fallow land conversions, and forest area changes (excludes non-forest tree categories including commercial plantations). We show that cropland to fallow conversions are prominently associated with lack of irrigation and capital, male agricultural labor shortage, and fragmentation of land holdings. We find gross forest loss is substantial and increased from ~23,810 km² (1985–1995) to ~25,770 km² (1995–2005). The gross forest gain also increased from ~6000 km² (1985–1995) to ~7440 km² (1995–2005). Overall, India experienced a net decline in forest by ~18,000 km² (gross loss–gross gain) consistently during both decades. We show that the major source of forest loss was cropland expansion in areas of low cropland productivity (due to soil degradation and lack of irrigation), followed by industrial development and mining/quarrying activities, and excessive economic dependence of villages on forest resources.

     

Modeling spatio-temporal change patterns of forest cover: a case study from the Himalayan foothills (India)

The present study used temporal remote sensing data for 1990, 2001 and 2006 to assess spatio-temporal patterns of forest cover changes in Shiwalik range of the Himalaya, Dehradun forest division. Forests are innately associated to human well-being. However, with the increasing anthropogenic activities, deforestation has increased. Quantitative change analysis of the forest cover for the past two decades provides valuable insight into the forest conservation vis-à-vis anthropogenic activities in the region. Spatio-temporal datasets along with biotic and abiotic variables provide opportunities to model the forest cover change further. The present study investigates forest cover change and predicts status of forest cover in the Dehradun forest division. Land Change Modeller (LCM) was used to predict status of forest cover for 2010 and 2015 using current disturbance scenarios. Comparing actual LULC of 2006 with the predicted LULC of 2006 validated change prediction model and agreement was 61.03%. The forested areas are getting degraded due to anthropogenic activities, but deforestation/degradation does not contribute much in expanding urban area. Agricultural areas and fallow lands are the main contributors to increased urban area. The study demonstrates the potential of geospatial tools to understand spatio-temporal forest cover change and generate the future scenarios.     

Potential synergies of the main current forestry efforts and climate change mitigation in Central Africa

In Central Africa, important carbon stocks are stored in natural forest stands, while activities that modify the carbon storage occur in the forest landscape. Besides clean development mechanisms, the reduction of emission through deforestation and degradation (REDD) initiative is viewed as one way to mitigate climate change. Important forest habitat protection activities have already been implemented with the aim of conserving the biodiversity of the region in a sustainable manner. The main causes of land use changes in the region are small holder subsistence practices and logging activities. Agricultural production has low productivity levels and therefore investments in improved agricultural techniques can both reduce pressure on existing forests and perhaps allow for the reforestation of existing degraded lands. The logging industry is dominated by large, industrial scale, logging operations performing selective logging of specific species and large trees. The adoption of improved forest management practices can reduce the impact of such logging on the ecological integrity and carbon stocks. Some efforts to engage in the carbon market have begun in the region. Further research is needed into the types of projects that will most likely become successful in the region and what locations will offer the greatest benefits.     

A mathematical model to investigate the impact of overgrowing population-induced mining on forest resources

Here, we develop a mathematical model which investigates the impact of growing population and rampant mining on forest resources, present in an urban region. In order to demonstrate the effect imposed by the overgrowing population on the environment, population pressure is incorporated in the model, which augments mining activities in the given region. The obtained model is studied qualitatively using stability theory of differential equations, while it is quantitatively analyzed through numerical simulation. The results of the model reveal that a whopping increase in unchecked mining activities, induced through excessive population growth, leads to declination of forest resources in a region. Therefore, sustainable mining is suggested through control measures imposed by the government on mining activities.     

Forest dynamics in Mississippi, USA: a hybrid statistical and geospatial analysis

Understanding forest changes and its trajectory is important to develop policy options and future scenarios for climate analysis. This research is conducted to gain insights on secondary forests change using Mississippi, USA, as a case study. We investigate the spatial patterns and temporal dynamics of secondary forests at high resolution and examine the forces driving their changes. An extensive literature review is conducted to refine the conceptual framework of forest changes and identify the underlying key factors. Forest changes are quantified at high spatial (30-m) and temporal (biennial) resolutions, using time series remotely sensed data between 1984 and 2007. A number of geospatial and socioeconomic data were compiled to analyze the spatial variations of forest disturbances and their linkages to various socioeconomic, political, and biogeophysical factors. The results show that the secondary forests are highly dynamic and variable. Disturbances and regeneration occur continuously everywhere in a systematic and coordinated fashion. This pattern prevents an extensive disturbance and increases total forest cover. Market conditions (i.e., timber price) are the key predictor of the level and overall trend of forest disturbances. However, spatial patterns of forest dynamics cannot be explained by location-specific biophysical, socioeconomic, and policy factors identified in the literature. They can best be described by the ecological characteristics of the forests (i.e., the forest type and age distribution), which have a clear economic linkage. The research shows that regenerated forests frequently experience loss and gain of their extent, and their ecological characteristics change drastically on a short-term basis. These results point out challenges and opportunities in forest management and policy with regard to reforestation.     

Dynamics of Carbon Pools and Fluxes in Russia's Forest Lands

The state and results of studies on the carbon cycle of forests on lands of the Russian forest fund (total area 1172 × 10⁶ ha) are analyzed at the federal level. Consideration is given to changes in the areas of different categories of forest lands, the age structure of stands, the pool and deposition of carbon in the phytomass, and the organic carbon pool of soils over the period from 1966 to 1998; the dynamics of activity in the forest industry by years and the extent of pyrogenic transformation of the forest cover between 1990 and 2001; and carbon fluxes associated with forest exploitation, including carbon emission resulting from fires.     

The Dynamics of Species Composition and Abundance of Wasps from the Families Pompilidae, Sphecidae, and Vespidae (Hymenoptera: Aculeata) in Successional Pine Biogeocenoses of the Berezinskii Biosphere Reserve

The data on the dynamics of population size and species composition of wasps from the families Pompilidae, Sphecidae, and Vespidae were obtained in the course of long-term studies carried out in successional pine forests of the Berezinskii Biosphere Reserve. The abundance and species diversity of wasps were significantly higher in a polewood forest (40 years) than in a young forest (20 years) and mature moss forest (70 years). In an overgrown ride in the moss pine forest, the composition of dominant wasp species remained relatively stable during the seven-year period of observations, although the number of species and their abundance varied significantly from year to year, depending on the weather.     

Floristic contamination of suburban forests near the city of Ivanovo

In the course of floristic studies in suburban forests near the city of Ivanovo, 206 species of vascular plants have been recorded, including 39 invasive species (18.9%). Information on specific features of distribution and activity of introduced species growing feral and accidental weeds in different forest types is presented. The most aggressive species are distinguished. Factors responsible for the invasion of alien species to forest cenoses and main tendencies in their dynamics are discussed.     

The Role and Effectiveness of Local Institutions in the Management of Forest Biodiversity in New Dabaga-Ulongambi Forest Reserve,Iringa Region-Tanzania

This paper examines the role and effectiveness of local institutions in the management of forest biodiversity in New Dabaga-Ulongambi Forest Reserve,Tanzania.Data were obtained through questionnaires,interviews,focus group discussions,participatory rural appraisal and field observations.The study revealed that the most remarkable local institutions connected to forest biodiversity management include:Village Natural Resources Management Committee(92%),tree nursery group(79.4%),beekeeping groups(61.1%),fish farming(43.3%),livestock rearing group(33.9%).Main activities carried out by local institutions which directly contribute to the sustainability of forest reserve include:forest patrols,fire extinguish,preparation of fire breaks,planting of trees along the forest boundaries,creation of awareness,arresting of forest defaulters,participation in income generation activities.For the purpose of realization that local communities are capable of managing forest biodiversity through their traditional institutions,the policy should provide tangible opportunity for local communities to meet their needs as they manage the forests.     

The ecology and behavioral features of dragonflies (Insecta,Odonata) in the forest–steppe zone of Central Chernozem region

The species composition of Odonata facultatively associated with forest ecosystems at the adult stage have been studied in the forest–steppe of Central Chernozem region. Factors facilitating the entry of adult dragonflies deep into forested areas, specific features of their behavior in the forest, and the role of human activities in the spread of these insects in forest ecosystems have been elucidated.     

The Role and Effectiveness of Local Institutions in the Management of Forest Biodiversity in New Dabaga-Ulongambi Forest Reserve,Iringa Region-Tanzania

Abstract

This paper examines the role and effectiveness of local institutions in the management of forest biodiversity in New Dabaga-Ulongambi Forest Reserve, Tanzania. Data were obtained through questionnaires, interviews, focus group discussions, participatory rural appraisal and field observations. The study revealed that the most remarkable local institutions connected to forest biodiversity management include: Village Natural Resources Management Committee (92%), tree nursery group (79.4%), beekeeping groups (61.1%), fish farming (43.3%), livestock rearing group (33.9%). Main activities carried out by local institutions which directly contribute to the sustainability of forest reserve include: forest patrols, fire extinguish, preparation of fire breaks, planting of trees along the forest boundaries, creation of awareness, arresting of forest defaulters, participation in income generation activities. For the purpose of realization that local communities are capable of managing forest biodiversity through their traditional institutions, the policy should provide tangible opportunity for local communities to meet their needs as they manage the forests.     

Forest Monitoring in Urbanized Areas

Long-term stationary investigations in permanent plots have been performed in forests of different types growing in Greater Moscow. Their results have made it possible to reveal the trends essential to the dynamics of these forests and make a prognosis of their condition in the near future. Moreover, they suggest that it is necessary to review some long-standing concepts concerning the processes of forest formation, relationships between the main forest species, etc.     

Involving local farmers in rehabilitation of degraded tropical forests: some lessons from Ghana

The role of community-based plantation development in forest rehabilitation and poverty alleviation is a pressing issue for the government of Ghana. In this paper, we present an analysis of the prospects of a community-based plantation using taungya systems and indigenous trees as means to forest rehabilitation and livelihood improvement in Ghana. The project management strategies, communication process and incentive mechanism and their impact on local participation are discussed with the aim to recommending a mechanism through which local farmers can best be involved in rehabilitation of degraded sites in the future in Ghana. Data were collected through a survey using personal interviews of 431 farming households and ten key informants from ten communities living in scattered hamlets in and around forests reserves. The results show a high rate of local participation in project tree planting activities. Four years after the project’s initiation, about 250 ha of plantations had been established using twelve priority indigenous and one exotic species and farmers had indicated improvement in their farming practices and availability of food and forest products. Restoring forest quality as a timber resource and associated values, getting money, food stuff and timber and non-timber for domestic use, and having access to fertile land for farming were the top three issues prioritised by respondents as motivational factors for engaging in the project activities. Overall, this project demonstrates that reversing tropical forest degradation is possible. For this we need local involvement in tree domestication combined with activities that addresses livelihood needs and environmental concerns. This case also demonstrates the prospects of utilising indigenous tree species, not only exotic species that dominated tree planting in the past, for plantations and landscape rehabilitation in Ghana. Readers should send their comments on this paper to BhaskarNath@aol.com within 3 months of publication of this issue.     

Quantifying disturbance effects on vegetation carbon pools in mountain forests based on historical data

Although the terrestrial carbon budget is of key importance for atmospheric CO₂ concentrations, little is known on the effects of management and natural disturbances on historical carbon stocks at the regional scale. We reconstruct the dynamics of vegetation carbon stocks and flows in forests across the past 100 years for a valley in the eastern Swiss Prealps using quantitative and qualitative information from forest management plans. The excellent quality of the historical information makes it possible to link dynamics in growing stocks with high-resolution time series for natural and anthropogenic disturbances. The results of the historical reconstruction are compared with modelled potential natural vegetation. Forest carbon stock at the beginning of the twentieth century was substantially reduced compared to natural conditions as a result of large scale clearcutting lasting until the late nineteenth century. Recovery of the forests from this unsustainable exploitation and systematic forest management were the main drivers of a strong carbon accumulation during almost the entire twentieth century. In the 1990s two major storm events and subsequent bark beetle infestations significantly reduced stocks back to the levels of the mid-twentieth century. The future potential for further carbon accumulation was found to be strongly limited, as the potential for further forest expansion in this valley is low and forest properties seem to approach equilibrium with the natural disturbance regime. We conclude that consistent long-term observations of carbon stocks and their changes provide rich information on the historical range of variability of forest ecosystems. Such historical information improves our ability to assess future changes in carbon stocks. Further, the information is vital for better parameterization and initialization of dynamic regional scale vegetation models and it provides important background for appropriate management decisions.     

杭州湾南岸滨海平原土地利用/覆被空间格局变化分析

杭州湾南岸滨海平原位于沪、杭、甬经济金三角的中心地带,是我国沿海经济最发达的地区之一。研究其土地利用/覆被空间格局变化对合理利用土地资源,促进沿海地区的可持续发展具有重要意义。利用1987年和2000年2个时期的TM影像,分析了杭州湾南岸滨海平原土地利用/覆被数量及空间格局变化特征。结果表明,杭州湾南岸滨海平原建设用地、水体和养殖用地呈现明显的增长趋势,水田、旱地、滩地、林地和盐田呈减少趋势。受自然和人类活动的共同影响,土地利用/覆被类型斑块平均面积由0.245 km2降至0.173 km2,斑块密度则由4.081个/km2提高到5.781个/km2,斑块数量增加了42%。由于斑块的破碎化,大部分土地利用/覆被类型的边界密度、形态指数、分维数和斑块密度都有不同程度的增加。城市化和非农化的发展使得建设用地格局指数变化表现出一定的特殊性。