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Tradicionalmente, el efecto combinado de la demografía y la productividad de los ambientes patagónicos ha sido invocado para explicar que el interior del bosque del centro-norte de la Patagonia argentina fue utilizado luego de la ocupación de espacios más favorables, con una antigüedad máxima de 3.500 años. El hallazgo de contextos del Holoceno temprano y medio en el sitio de Población Anticura situado en el bosque mixto permite reformular este escenario. El análisis sedimentario, de los procesos de formación y de la evidencia arqueológica recuperada indica, para estos momentos, la existencia de ocupaciones breves y con cierta redundancia a través del tiempo, con conjuntos artefactuales pequeños pero variados, una subsistencia basada en el huemul (Hippocamelus bisulcus) y el consumo ocasional de especies de menor tamaño corporal como alimento y como materia prima. La procedencia de algunos materiales sugiere que el uso temprano del interior del bosque estaría vinculado a redes de circulación amplias en el marco de una baja demografía, mientras que la naturaleza de las ocupaciones muestra un conocimiento del ambiente que señala que los contextos más antiguos de Población Anticura no reflejan la primera exploración del interior del bosque.
This contribution discusses possible relationships between human populations and Holocene environmental deterioration phenomena (cold/arid pulses and volcanic eruptions) in the Fuegian Archipelago (South America), based on summed probability distributions of archaeological dates, paleoenvironmental information, geospatial data, and archaeological evidence. During the first millennia after peopling, only the Hudson (ca. 7700 cal yr BP) and the first Monte Burney (ca. 8600 cal yr BP) eruptions might have played a role in human dispersion. Particularly, a more intense human occupation around the Beagle Channel and long-distance interactions are proposed as risk-buffer strategies related to the Hudson eruption. A cooling phase and a demographic growth at ca. 5500 cal yr BP might have favored more dispersed spatial occupations and a subsistence diversification in the Beagle Channel. In the northern steppes, the second Monte Burney eruption (ca. 4300 cal yr BP) and an arid episode (ca. 2600 cal yr BP) are proposed as the main triggers for changes in land-use patterns, long-network interactions, and subsistence strategies. Even though occupation changes in the Fuegian Archipelago coexist with environmental deterioration episodes after 1500 cal yr BP, demographic processes and the European colonization most likely explain this trend. Similarities between the steppe/ecotone and forest occupation curves suggest common behavioral patterns across the Holocene.
Although the disaster reduction effects of forest braking have long been known empirically, they have not been known in detail down to recent. In this study, we ascertained forest braking effect by numerical simulations using the avalanche dynamics program, TITAN2D, to model large-scale avalanches. One of these avalanches occurred in the Makunosawa valley, Myoko, and damaged a cedar forest; the others occurred on Mt. Iwate and damaged a subalpine forest. All avalanches damaged many trees and terminated within the forests. In our simulations, the resistance of the forests to avalanches is simulated using a larger bed friction angle. Fitting the observations from the Makunosawa avalanche by trial and error, a bed friction angle of 13–14° in the non-forested area and of 25° in the forested area is obtained. We conducted simulations of the Mt. Iwate avalanches using the same method as for the Makunosawa valley avalanche, and obtained good agreement between observations and simulations. Simulations reveal that without the forest, the avalanche would have traveled at least 200 m farther than the forest's actual end in the Makunosawa valley, and at least 200 m and possibly up to 600 m farther on Mt. Iwate. This study therefore clearly shows that forests provide a braking effect for avalanches.
Snowmelt was measured on a daily basis for 17 days at the open site and 18 days at three Japanese cedar sites with canopy closure of 17.8% (cedar stand A), 5.2% (B) and 2.4% (C) in April. Measured daily snowmelt at each site was reproduced by heat-balance calculation with an accuracy of <±1 mm w.e. From 1st April to the date of snow disappearance net radiation accounted for 88.4, 43.0, 32.7 and 34.2% of total snowmelt energy at the open site, the cedar stands A, B and C, respectively. The ratio of sensible and latent heat to total snowmelt was 33.1–37.9 and 25.9–29.4%, respectively, at three cedar stands. The ratios of sensible and latent heat increased over time in accordance with the rise in temperature at all cedar sites. They became large on a daily basis when air temperature and/or wind speed were high. Wind speed is dependent on morphology around each site that also dictated snowmelt.
Twenty-seven species and two subspecies of Ficus are reported from one study site in central Africa. Characters for identification are explained. An identification key, illustrations, descriptions and habitats are provided. The species-level diversity of Ficus in tropical forests is discussed.
We explore the optimal regulation of forest carbon and albedo for climate change mitigation. We develop a partial equilibrium market-level model with socially optimal carbon and albedo pricing and characterize optimal land allocation and harvests. We numerically assess the policy's market-level impacts on land allocation, harvests, and climate forcing, and evaluate how parameter choices (albedo strength, productivity of forest land, and carbon and albedo prices) affect the outcomes. Carbon pricing alone leads to an overprovision of climate benefits at the expense of food and timber production. Complementing the policy with albedo pricing reduces these welfare losses.
The flora of Laos remains one of the least known within the Indo-Burma biodiversity hotspot. A floristic inventory was carried out in Phou Hin Poun National Biodiversity Conservation Area, an under-explored area of the Khammouane Limestone. This study provides a list of 27 taxa that are additions to the most recent country checklists. The Ebenaceae, Euphorbiaceae and Myrtaceae are the families with the highest species number. In this list, four species are endemic to Indochina (Cambodia, Laos and Vietnam): Cynometra dongnaiensis Pierre, Jasminum vidalii P.S.Green, Memecylon chevalieri Guillaumin and Pothos gigantipes Buchet ex P.C.Boyce. These results illustrate the paucity of our knowledge of the region surveyed and of the flora of Laos in general.
A long-standing problem in avalanche science is to understand how forests stop avalanches. In this paper we quantify the effect of forests on small and medium avalanches, crucial for road and skirun safety. We performed field studies on seven avalanches where trees affected the runout. We gathered information concerning the release zone location and dimension, deposition patterns and heights, runout distance and forest structure. In these studies the trees were not destroyed, but acted as rigid obstacles. Wedge-like depositions formed behind (1) individual tree stems, (2) dense tree groups and (3) young trees with low-lying branches. Using the observations as a guide, we developed a one-parameter function to extract momentum corresponding to the stopped mass from the avalanche. The function was implemented in a depth-averaged avalanche dynamics model and used to predict the observed runout distances and mean deposition heights for the seven case studies. The approach differs from existing forest interaction models, which modify avalanche friction to account for tree breakage and debris entrainment. Our results underscore the importance of forests in mitigating the danger from small-to-medium avalanches.
The relationship between heritage management and nature conservation in Sweden has changed over time, from an earlier division between the two sectors – with nature conservation attached to the growing movement of environmental politics – towards more integrated ways of working under the umbrella of sustainable development. As forests have been associated with nature, the earlier divide has been more evident with forested areas than agricultural areas, a view that has contributed to the marginalization of such landscapes and their inhabitants. With the more integrated policy, heritage management is drawn into the societal discourse of ecological modernization, where environmental and sustainability issues have become new business ideas and sources of further economic growth. From an ecological modernization perspective, nature and cultural heritage are today (touristic) commodities, enforcing the power of the urban world over the rural world and thus risk contributing to further marginalization of the inhabitants. However, heritage sites appear to function as boundary objects in local communities, and may thus function as meeting places and sources of enhancement of community pride. Therefore, we argue for community participation and public communication within the heritage sector, especially concerning marginalized, forested landscapes in order to contribute to an increased knowledge and understanding of the local heritage and history, thus opening the way for creative local processes.
Miombo woodlands supply ecosystem services to support livelihoods in southern Africa, however, rapid deforestation has necessitated greater knowledge of tree growth and off-take rates to understand the sustainability of miombo exploitation. We established 48 tree inventory plots within four villages in southern Malawi, interviewed representatives in these same villages about tree management practices and investigated the impact of climate on vegetation dynamics in the region using the ecosystem modelling framework LPJ-GUESS. Combining our data with the forest yield model MYRLIN revealed considerable variation in growth rates across different land uses; forested lands showed the highest growth rates (1639 [95% confidence interval 1594–1684] kg ha–1 year–1), followed by settlement areas (1453 [95% confidence interval 1376–1530] kg ha–1 year–1). Based on the modelled MYRLIN results, we found that 50% of the villages had insufficient growth rates to meet estimated off-take. Furthermore, the results from LPJ-GUESS indicated that sustainable off-take approaches zero in drought years. Local people have recognized the unsustainable use of natural resources and have begun planting activities in order to ensure that ecosystem services derived from miombo woodlands are available for future generations. Future models should incorporate the impacts of human disturbance and climatic variation on vegetation dynamics; such models should be used to support the development and implementation of sustainable forest management.
The orang-utan Pongo spp. is protected by national and international legislation, yet populations continue to decline. Many reports implicate local people in the poaching and illegal trade in orang-utans, yet community participation has been promoted as an alternative conservation strategy. To explore how community-based orang-utan conservation could be developed, we conducted a study to understand informal institutions, particularly local people's perceptions, traditional beliefs, taboos, norms and knowledge, related to orang-utan conservation within and around the wetlands of Danau Sentarum. The majority of Dayak communities interviewed practised traditional taboos, which supported the protection of orang-utans and their habitat. Statistical analysis using generalized linear modelling indicated that more orang-utan nests were found in areas with both good habitat condition and strong informal institutions. Despite applying traditional systems that are similar to conservation, local people have negative perceptions about the term ‘conservation’. We describe the underlying causes of these negative perceptions and highlight their implications for conservation programmes and policies. We conclude that conservation of orang-utans and other species should not focus on single species but on maintaining social and natural capital, cultural diversity and ecological functions at various institutional levels and across geographical scales.
We reconstructed the late Holocene vegetation of the Nain region (northern Labrador, northeastern Canada) in order to assess the influence of climate and historic land use on past shifts in forest composition. Chronostratigraphy was used in combination with macrofossil and pollen data from monoliths sampled from four peatlands. Paleoecological reconstructions produced a vegetation history spanning 4900 years for the Nain region that is largely concordant with other studies in Labrador. An initial open forest tundra phase was followed by an increase in tree cover at around 2800 cal yr BP. Paludification began ∼200 cal yr BP. A decline in Picea and its subsequent disappearance from most of the sites occurred ∼170 cal yr BP (AD 1780) in a period of relatively mild conditions during the Little Ice Age. This event was followed by the establishment of Larix laricina in the region. Local anthropogenic factors are likely responsible for these later developments, as they were not observed in other regional studies. The period around AD 1780 corresponds to the establishment of the Moravian missionaries on the Labrador coast, which increased the need for fuel and lumber. We conclude that changes in land use are reflected in the patterns of vegetation and hydrological change at the study sites.
Adaptation to the consequences of climate change has developed into a growing field of concern for the insurance business. However, climate-related risk is not entirely a new field in insurance. Historically, a large number of insurance organisational choices and strategies have been used to mitigate the financial impact of extreme events and uncertainties associated with climate change. Taking the case of forests in Sweden, this article reviews the ways in which climate-related risks such as storm/wind and fire risks have been assured. The study shows that climate-related risks have generally increased over time and that major hazard events have been decisive for strategy and organisation choices. Twentieth-century developments show that corporate insurance coverage increased due to higher levels of anticipated risk, while self-insurance and public insurance were reduced. However, in more recent times the expansion of corporate insurance has stagnated. Increased premiums and tighter terms following historically extreme weather events have led government and forest owners to assume more climate risks.
Although not categorized as threatened on the IUCN Red List, the African forest buffalo Syncerus caffer nanus is declining across its range. In Nigeria its distribution, abundance and status are virtually unknown. We conducted interviews with experienced hunters, and field surveys (linear and recce transects), to study the buffalo's distribution and ecology in the montane forests of Cross River State. General linear modelling indicated that the number of individuals varied significantly across survey areas and habitat types but not with the survey period, and there was no study area × study period interaction. Buffalo were found most commonly in mature and secondary forests. Given the species’ scattered distribution, fragmentation of its habitat, and the relatively low numbers observed, Nigerian populations require a separate, regional categorization on the IUCN Red List.
Plasmodium knowlesi a simian malaria parasite is currently affecting humans in Southeast Asia. Malaysia has reported the most number of cases and P. knowlesi is the predominant species occurring in humans. The vectors of P. knowlesi belong to the Leucosphyrus group of Anopheles mosquitoes. These are generally described as forest-dwelling mosquitoes. With deforestation and changes in land-use, some species have become predominant in farms and villages. However, knowledge on the distribution of these vectors in the country is sparse. From a public health point of view it is important to know the vectors, so that risk factors towards knowlesi malaria can be identified and control measures instituted where possible. Here, we review what is known about the knowlesi malaria vectors and ascertain the gaps in knowledge, so that future studies could concentrate on this paucity of data in-order to address this zoonotic problem.
We assessed the impacts of crop raiding by wild mammals on the livelihoods of smallholding farmers in south-western Ethiopia. Data were generated through participatory field mapping, interviews and focus groups. The results indicated that wild mammals, mainly olive baboons Papio anubis and bush pigs Potamochoerus larvatus, were raiding most crops cultivated in villages close to forests. In addition to the loss of crops, farmers incurred indirect costs in having to guard and cultivate plots far from their residences, sometimes at the expense of their children's schooling. Raiding also undermined farmers’ willingness to invest in modern agricultural technologies. Various coping strategies, including guarding crops and adapting existing local institutions, were insufficient to reduce raiding and its indirect impacts on household economies to tolerable levels, and were undermined by existing policies and government institutions. It is essential to recognize wild mammal pests as a critical ecosystem disservice to farmers, and to identify ways to mitigate their direct and indirect costs, to facilitate local agricultural development and livelihood security, and integrate wildlife conservation and local development more fully in agriculture–forest mosaic landscapes.
Understanding the potential for ecosystem transformation and community change in response to climate variability is central to anticipating future ecological changes, and long-term records provide a primary source of information on these dynamics. We investigated the late Holocene history of upland forest and peatland development at Cranesville Swamp, a peatland located along the West Virginia–Maryland border in the USA. Our primary goal was to determine whether establishment of peatland was triggered by moisture variability, similar to recent developmental models derived from depressional peatlands in glaciated regions. Results indicate that the peatland established at about 1200 cal yr BP, and was associated with a dramatic and persistent change in upland forest composition. Furthermore, timing of these upland and wetland ecological changes corresponded with evidence for multidecadal drought and enhanced moisture variability from nearby tree-ring and speleothem climatic reconstructions. Our results add to a growing body of research highlighting the sensitivity of both peatland development and upland forest communities to transient drought and enhanced moisture variability, and suggest that enhanced moisture variability in the future could increase the probability of similarly abrupt and persistent ecological change, even in humid regions like eastern North America.
This article examines postcolonial representations of the jungle and the desert, focusing on two novels in particular: Étienne Goyémidé’s Le silence de la forêt (1984) and Tahar Djaout’s L’invention du désert (1987). Postcolonial literary representations of these “extreme” landscapes are layered with allusions and almost always engage in an intertextual conversation with the colonial genres that influenced readers’ conception of these spaces. The specificity of jungle and desert serves in contemporary postcolonial literature as a foil to homogenizing forces of both the past and the present, as seen in the stylistic techniques authors employ to depict these spaces. These stylistic techniques often work in two seemingly opposing directions: they “naturalize” landscapes that are often portrayed as inhuman and contrast them to the “unnatural” structures of colonial and postcolonial society, while at the same time embodying and claiming the distortion or disorientation inherent in those landscapes. These complex, multifaceted, geographically rooted descriptions, which incorporate and react to a variety of historical and cultural factors, take what I call an ecosystem approach, rather than continuing to rely on a false nature/culture division.
Although trees have high economic, cultural and ecological value, increasing numbers of species are potentially at risk of extinction because of forest loss and degradation as a result of human activities, including overharvesting, fire and grazing. Emerging threats include climate change and its interaction with the spread of pests and diseases. The impact of such threats on the conservation status of trees is poorly understood. Here we highlight the need to conduct a comprehensive conservation assessment of the world's tree species, building on previous assessments undertaken for the IUCN Red List. We suggest that recent developments in plant systematics, online databases, remote sensing data and associated analytical tools offer an unprecedented opportunity to conduct such an assessment. We provide an overview of how a Global Tree Assessment could be achieved in practice, through participative, open-access approaches to data sharing and evaluation.
The Tropical Andes are characterized by a high level of endemism and plant species richness but are under pressure from human activities. We present the first regional conservation assessment of upper montane tree species in this region. We identified 3,750 tree species as occurring in this region, of which 917 were excluded because of a lack of data on their distribution. We identified a subset of 129 taxa that were restricted to higher elevations (> 1,500 m) but occurred in more than one country, thus excluding local endemics evaluated in previous national assessments. Distribution maps were created for each of these selected species, and extinction risk was assessed according to the IUCN Red List categories and criteria (version 3.1), drawing on expert knowledge elicited from a regional network of specialists. We assessed one species, Polylepis microphylla, as Critically Endangered, 47 species as Endangered and 28 as Vulnerable. Overall, 60% of the species evaluated were categorized as threatened, or 73% if national endemics are included. It is recommended that extinction risk assessments for tree species be used to inform the development of conservation strategies in the region, to avoid further loss of this important element of biodiversity.