Determining the most suitable intensities for precommercial thinning (PCT) in oriental beech (Fagus orientalis) stands, which cover substantial areas in Turkey and have a high economic and ecological value, is essenti...Determining the most suitable intensities for precommercial thinning (PCT) in oriental beech (Fagus orientalis) stands, which cover substantial areas in Turkey and have a high economic and ecological value, is essential to provide higher economic return and obtain well-formed stems. The effects of various rates of PCT interventions on the growth characteristics of natural stands, located in the northern part of Turkey, were explored to determine appropriate thinning rates;24 experimental PCT plots (4 PCT rates × 3 replications × 2 sites) were established in young thicket-stage stands and four precommercial thinning rates such as light (1 – 1.5 m spacing), moderate (1.5−2.0 m spacing) and heavy (2.5–3.0 m spacing) thinning, including a control plot (i.e., untreated), were applied. At the end of the 2007 and 2010 growing seasons, the diameter and height of the trees were measured and growth analyzed based on the 3-year and 6-year incremental growth. PCT levels were found to have significant (P < 0.05) effects on diameter, height, total basal area and total volume increment at the end of each period. The mean diameter and height increment proportionally increased with increasing PCT intensity in the third and the sixth year. In both sites, the moderate PCT provided the greatest total basal area and total volume increment. The early results indicate that the moderate PCT (1.5–2 m spacing) boosted stand development over time.展开更多
The Southern African biomes are complex biotic communities, with its distinctive plant and animal species, and are maintained under the suitable climatic conditions of the region. It includes the Fynbos Biome and the ...The Southern African biomes are complex biotic communities, with its distinctive plant and animal species, and are maintained under the suitable climatic conditions of the region. It includes the Fynbos Biome and the Succulent Karoo Biome, which forms the smallest of the world’s six Floristic Kingdoms, and they are of conservation concern. The other six biomes are Albany Thicket, Desert, Grassland, Indian Ocean Coastal belt, Nama-Karoo, Savanna. The biomes are not only threatened by agricultural expansion, overgrazing, and mining;but also by future climate changes and droughts. This study investigates the how to best model the possible vulnerable biome areas, under future climate changes, and how Southern African geology plays a huge role in the restriction of the biome shifts. It provides evidence regarding the importance of the study to understanding the climate change impacts and the geological variables on the Southern African biomes, in terms of possible future biome habitat loss.展开更多
Assessing land cover changes from the 1991 to 2011 for Itigi thicket is imperative for determining changes between land cover types and understanding anthropogenic impact during this period. Remote sensing (RS) data, ...Assessing land cover changes from the 1991 to 2011 for Itigi thicket is imperative for determining changes between land cover types and understanding anthropogenic impact during this period. Remote sensing (RS) data, Geographic Information System (GIS) techniques and forest inventory data were used. ILWIS 3.3 Academic software was used to analyze the satellite imageries to determine the land use, land cover change;while data on anthropogenic activities were analysed in MS Excel software. The results showed that between 1991/2000 and 2000/2011, the areas of thicket declined by 6.23% while non-thicket areas increased by 3.92%. The decline in thicket areas was attributed to increase in anthropogenic activities such as wood extraction, clearing for agriculture, livestock grazing and fires. The study highlights the importance of integrating remote sensing and forest inventory in understanding the thicket resources dynamics and generating information that could be used to overcome the Itigi thicket problems for the sustainability of this unique vegetation.展开更多
文摘Determining the most suitable intensities for precommercial thinning (PCT) in oriental beech (Fagus orientalis) stands, which cover substantial areas in Turkey and have a high economic and ecological value, is essential to provide higher economic return and obtain well-formed stems. The effects of various rates of PCT interventions on the growth characteristics of natural stands, located in the northern part of Turkey, were explored to determine appropriate thinning rates;24 experimental PCT plots (4 PCT rates × 3 replications × 2 sites) were established in young thicket-stage stands and four precommercial thinning rates such as light (1 – 1.5 m spacing), moderate (1.5−2.0 m spacing) and heavy (2.5–3.0 m spacing) thinning, including a control plot (i.e., untreated), were applied. At the end of the 2007 and 2010 growing seasons, the diameter and height of the trees were measured and growth analyzed based on the 3-year and 6-year incremental growth. PCT levels were found to have significant (P < 0.05) effects on diameter, height, total basal area and total volume increment at the end of each period. The mean diameter and height increment proportionally increased with increasing PCT intensity in the third and the sixth year. In both sites, the moderate PCT provided the greatest total basal area and total volume increment. The early results indicate that the moderate PCT (1.5–2 m spacing) boosted stand development over time.
文摘The Southern African biomes are complex biotic communities, with its distinctive plant and animal species, and are maintained under the suitable climatic conditions of the region. It includes the Fynbos Biome and the Succulent Karoo Biome, which forms the smallest of the world’s six Floristic Kingdoms, and they are of conservation concern. The other six biomes are Albany Thicket, Desert, Grassland, Indian Ocean Coastal belt, Nama-Karoo, Savanna. The biomes are not only threatened by agricultural expansion, overgrazing, and mining;but also by future climate changes and droughts. This study investigates the how to best model the possible vulnerable biome areas, under future climate changes, and how Southern African geology plays a huge role in the restriction of the biome shifts. It provides evidence regarding the importance of the study to understanding the climate change impacts and the geological variables on the Southern African biomes, in terms of possible future biome habitat loss.
文摘Assessing land cover changes from the 1991 to 2011 for Itigi thicket is imperative for determining changes between land cover types and understanding anthropogenic impact during this period. Remote sensing (RS) data, Geographic Information System (GIS) techniques and forest inventory data were used. ILWIS 3.3 Academic software was used to analyze the satellite imageries to determine the land use, land cover change;while data on anthropogenic activities were analysed in MS Excel software. The results showed that between 1991/2000 and 2000/2011, the areas of thicket declined by 6.23% while non-thicket areas increased by 3.92%. The decline in thicket areas was attributed to increase in anthropogenic activities such as wood extraction, clearing for agriculture, livestock grazing and fires. The study highlights the importance of integrating remote sensing and forest inventory in understanding the thicket resources dynamics and generating information that could be used to overcome the Itigi thicket problems for the sustainability of this unique vegetation.
