Search results for "forest"
showing 10 items of 3780 documents
Using SMAA-2 method with dependent uncertainties for strategic forest planning
2006
Abstract Uncertainty included in forest variables is normally ignored in forest management planning. When the uncertainty is accounted for, it is typically assumed to be independently distributed for the criteria measurements of different alternatives. In forest management planning, the factors introducing the uncertainty can be classified into three main sources: the errors in the basic forestry data, the uncertainty of the (relative) future prices of timber, and the uncertainty in predicting the forest development. Due to the nature of these error sources, most of the involved uncertainties can be assumed to be positively correlated across the alternative management plans and/or criteria.…
Building and evaluating predictive occupancy models for the Siberian flying squirrel using forest planning data
2005
Abstract We analyzed the applicability of forest planning data in predicting the occurrence of the Siberian flying squirrel (Pteromys volans) in managed northern boreal forests, in northeast Finland. Forest planning data is a source of information about forest characteristics for forest managers that may be used in estimating the availability of certain habitats for species conservation. Flying squirrel populations have declined in Finland, most probably due to habitat change and loss and maintenance of suitable habitats can be seen as a fundamental task in species conservation. First, we surveyed 715 ha of older spruce-dominated forest consisting of 91 stands, of which 35 were found occupi…
Testing Ikonos and Landsat 7 ETM+ Potential for Stand-Level Forest Type Mapping by Soft Supervised Approaches
2003
Forest types can be adopted as a suitable reference for classifying survey units within multipurpose forest resources inventories, at the properly considered level. This kind of hierarchical classification approach integrates an ecologically meaningful per-habitat perspective with practical survey, planning and management requirements. Advanced remote sensing technologies can be valuable tools for a cost-effective implementation of such an approach. In the present paper, data from high (Landsat 7 ETM+) and very high (Ikonos) spatial resolution satellite sensors were tested to understand their potential contribution supporting stand-level forest type mapping under Mediterranean conditions. I…
Global Public Goods and International Law: Insights from International Forest Protection
2021
The aim of the present article is to contribute to this endeavour by identifying the weak-nesses of, and the areas for improvement in, the current global forest regulatory and institu-tional framework, through an analysis conducted using the lens of the concept of global public goods as transposed into, and shaped by, the discipline of international law. To this end, Section 2 starts by providing an overview of the origins of the concept of global public goods in political science and economy. Section 3 brings to the fore the value that the in-ternational legal discipline might add to the global public goods discourse. Section 4 pro-ceeds by explaining forest sustainable management protecti…
Clinical and radiological features of Forestier's disease presenting with dysphagia
2018
Background Diffuse idiopathic skeletal hyperostosis (DISH), also known as Forestier's disease, is a rheumatologic condition characterized by ossification of the spinal ligaments and tendons. Large anterior osteophytes are typically present in the lower cervical levels, while upper cervical ossification resulting in dysphagia is very rare. Methods Here, we presented a patient with Forestier's disease involving massive ossification of the anterior longitudinal ligament extending from C3 to C4 downward contributing to severe dysphagia. Results A 65-year-old male presented with cervical pain and dysphagia. The computed tomography of the cervical spine demonstrated massive anterior longitudinal …
Mutualistic tree-frugivore interactions in Afrotropical forests : from local ecological knowledge to the identification of network interaction patter…
2022
Frugivory in tropical forests is a major ecological process, as most tree species rely on frugivores for their dispersion, and numerous animal species used fruits as their principal sources of food. However, frugivory networks between plants and animals in Afrotropical forests are poorly described, and the mechanisms shaping them remain largely unexplored. This PhD thesis addresses a structural approach of the frugivory network, a plant-community approach and a methodological approach using local ecological knowledge and cameras.The first chapter describes the frugivory network of Afrotropical forests, based on a compilation of frugivory interactions from the literature that comprised >10,0…
Human impact diminishes seedling species richness in Kakamega Forest, Kenya
2008
Summary Anthropogenic forest fragmentation and other kinds of human disturbance, such as selective logging, can reduce the diversity of plant and animal species. To evaluate the impact of fragmentation and small-scale disturbance on forest regeneration, we assessed species richness and total abundance of adult trees in comparison with seedlings in the heavily fragmented and disturbed Kakamega Forest, western Kenya. In nine differently disturbed 1-ha study blocks distributed across the main forest and fragments, we mapped all trees >10 cm in diameter at breast height. Additionally, we established ninety 1-m 2 seedling plots within these 1-ha study blocks which were monitored over 2.5 years. …
Fragmentation and local disturbance of forests reduce frugivore diversity and fruit removal in Ficus thonningii trees
2008
Clearance, fragmentation, and degradation of tropical forests have resulted in declines of biodiversity. This loss of biodiversity is endangering important ecosystem processes such as seed dispersal. If anthropogenic disturbances affect seed dispersal of keystone plants, effects on tropical ecosystems might be especially pronounced. We studied frugivore assemblages and fruit removal from 25 Ficus thonningii trees in the heavily fragmented and disturbed Kakamega Forest, western Kenya. During 400 observation hours we recorded 36 frugivores visiting F. thonningii trees. We recorded significantly fewer frugivorous species in fragments compared to the main forest and in highly, compared to littl…
Analysis of Geometrical Relationships and Friction Losses in Small-Diameter Lay-Flat Polyethylene Pipes
2016
[EN] The use of lay-flat polyethylene pipes to irrigate horticultural crops has been receiving widespread attention in the last decade, due to the significant improvements in their hydraulic performance, their potentially high application efficiency, and their limited installation costs. However, even if hydraulic design procedures for conventional microirrigation systems are fairly well established, there is still the need to know how different pipe-wall thicknesses of lay-flat pipes can affect the pipe geometry under different operating pressures as well as the related consequences on friction losses. This paper, after comparing two different procedures (caliper and photographic) to asses…
Effects of forest regeneration on the structure of bird communities in northern Finland
1985
Breeding bird communities in five stages of secondary forest succession were studied in northeastern Finland in 1980–82. Three groups of communities were distinguished: open land, brush phase and forest communities, dominated by Motacilla alba and Oenanthe oenanthe, Phylloscopus trochilus and Anthus trivialis, Phylloscopus trochilus and Fringilla montifringilla, respectively. Pair density, number of species, biomass of adult birds and species diversity increased in the course of succession, none of these, however, monotonously. Average bird weight showed a decreasing trend although the variation was considerable. The degree of specialization in communities (measured by ratios derived from n…