Replanting conifer seedlings after pine weevil emigration in spring decreases feeding damage and seedling mortality

Replanting at appropriate times after harvesting a coniferous forest stand can help efforts to suppress seedling mortality caused by the pine weevil Hylobius abietis, but optimal times are uncertain. We hypothesized that planting in June rather than May in the third season after harvest would reduce feeding damage by the pine weevil and increase seedling survival rates in central Sweden, where new-generation weevils mainly fly away from their development sites in May/early June. An experimental test of the hypothesis in eight clear-cuts confirmed that planting in June instead of May reduced proportions of seedlings attacked by pine weevil, bark removal from seedlings’ stems, and proportions of seedlings killed by feeding damage. These differences between seedlings planted in May and June declined to some extent with time but still remained significant after two growing seasons. The total seedling mortality after two seasons did, however, not differ significantly between seedlings planted in May and June. Overall, 29% of all seedlings were killed by pine weevil, 4.0% by Hylastes bark beetles, and 2.3% by drought. The results indicate that replanting in spring during the third season after harvest can advantageously continue until mid-June with respect to damage and mortality.     

Land-use changes and sustainable development in mountain areas: a case study in the Spanish Pyrenees

Land-use changes affecting Mediterranean mountains represent the intensification of use in valley bottoms, accompanied by land-use conflicts, and a generalized abandonment of the hillslopes, which in the past were perfectly integrated in the system of land management. Farmland abandonment, reforestation, diminution of the livestock pressure and substitution of cereal crops by meadows are the most outstanding features of the recent land-use changes. The question is whether the new spatial organisation is in accordance with a longterm policy of sustainable development in mountain areas. The results obtained confirm that farmland abandonment on steep slopes — and the resulting colonization of old fields by a dense shrub cover — and afforestation contribute to control both soil erosion and surface runoff. As a result some of the most important rivers and alluvial fans have recently stabilized their sedimentary structures.     

THE ENVIRONMENTAL CHARACTERISTICS OF FOREST LAND AND THE TECHNIQUES OF REFORESTATION IN FIRED LAND IN DAXING''''AN MOUNTAINS

INTRODUCTIoNAfertheGreatforestfireonMay6inl987,theauthorhasdoneaseriesofresearchworkforacceleratingregenerationofforestvegetationandpromotingestablisIunentofstand.TheyareasfollowingfA.Analysisofnaforeenvironmentalcon-dition.Authorhasmainlyanalysischaractersofnaforecondition,theregulationofforestvegetationsuccessionandthe4ifferenceofforestsites.Thisisthetechnicalbasetolnydownrestorationandplantationinfrigidre-gion.B.Evaluationofselectionandintegrationrestorationandplantationoftechniques,…     

Comanaged Forests in West Bengal

Abstract

The forests of West Bengal have recently come under a comanagement initiative called Joint Forest Management. This paper will examine changing forestry regimes in southern West Bengal since the 1930s to suggest that the redefinition of forest management in the region since the mid 1980s cannot adequately be explained in terms of property rights. The nature of village community, overlapping jurisdictions of different agencies and groups in forest management, and the nature of expertise qualifying the scope of jurisdictions-that of foresters and villagers-are intersecting issues that have to be analyzed to understand the institutional politics of comanaging natural resources worldwide.     

广西岩溶山区吊丝竹封山育林综合技术

根据广西岩溶山区现有吊丝竹低产疏残林资源、分布和生长状况,从封育条件、封育方式、人工补植、松土除草、施肥抚育、低产竹复壮、保留合理密度及主要病虫害防治等方面介绍了封山育林综合培育技术.     

Integration of albedo effects caused by land use change into the climate balance: Should we still account in greenhouse gas units?

Due to impacts of albedo on climate change, benefits of afforestation/reforestation regimes are under debate. In this paper we investigate how to incorporate albedo changes in a carbon accounting tool to show the net effect of land use change on the climate. Using a study area in southern Europe, albedo and carbon sequestration modelling results are linked to determine the combined radiative forcing balance. The results show that under specific circumstances afforestation/reforestation measures may not automatically have positive impacts in a global warming context because the cooling effect of most of the carbon sequestered is neutralized by the warming effect of albedo changes. However, sensitivity analyses lead to the conclusion that improved albedo data from satellite images (MODIS) could influence and enhance outputs significantly. The paper points out that accounting based exclusively on GHG units does not, in the case of land use change, reflect the entire picture. It is highly recommended that in future global warming impacts of land use systems and biogenic products (e.g. solid biomass, liquid biofuels) should be studied using life cycle assessments (LCA) and should include these additional—non-GHG effects—on climate change.     

Degradation,rehabilitation and sustainable management of a dunal ecosystem in central Italy

The history of the Feniglia Dune is an example of human-induced degradation and rehabilitation of a Mediterranean ecosystem. Between 1700 and 1900 the forest almost completely disappeared owing to intensive exploitation. The rehabilitation of Feniglia started at the beginning of 1900 with dune consolidation and the sowing of Mediterranean pines. Reforestation was long and complex, and was finished in the 1950s. The evolution of the vegetation can be studied from an aerophotogrammetric series (1955, 1968, 1985 and 1989). GIS was used to analyse the cartographic images. The vegetation dynamics was positive, showing increased plant cover at least until 1985. The 1989 map showed the beginning of cover recession, probably as the result of a number of concurrent disturbing factors: the evolution of the coastline, and an increase in grazing and tourism. Since the Feniglia Dune vegetation is not a resilient natural coenosis, it still needs the support of human interventions to safeguard its natural dynamism.     

Comparative performance of exotic and indigenous forest species for tropical semievergreen degraded forest land reforestation in Chittagong,Bangladesh

Exotic Acacia arabica, Acacia Auriculiformis, Eucalyptus camaldulensis, and Pinus caribaea, and indigenous Albizia lebbek, Cassia siamea, Chikrassia Tabularis, and Derris robusta were reforested in tropical semievergreen degraded forest lands to evaluate their capability of survival, growth, and biomass production in energy plantations. Three years after reforestation, significant variations in growth and biomass yield production were observed within each category of forest species. Both exotic and indigenous forest species had shown similar capability in the biomass production. Plant height was found a better predictor of biomass production than diameter at breast height. There have been improvements in soil properties under reforestation. Among the forest species, indigenous Cassia siamea and Derris robusta, and exotic Acacia auriculiformis were found highly adaptable, fast-growing, productive, and site improving, suitable for reforestation of degraded lands. Copyright © 1999 John Wiley & Sons, Ltd.     

Landscape changes as visible indicators in the social,economic and political process of soil erosion: A case study of the municipality of puebla de valles (Guadalajara Province), Spain

This paper proposes a methodological approach to data gathering as a sound basis for understanding land degradation processes, breaking down barriers of distrust between Government officials and land users, and promoting participation in planning for soil and water conservation. It examines how landscape changes, of value as indicators of erosion, are perceived by land users and can be used in planning. It is proposed that the participation of land users in the construction of questionnaires, data gathering, analysis and writing up of the findings are examples of the participatory initial stages in planning.