关于加强农田防护林采伐更新管理的通知 湘林资[2006]3号

各市州林业局:为切实加强农田防护林体系建设,充分发挥农田防护林体系在建设社会主义新农村中的作用,进一步加强和规范农田防护林采伐更新管理行为,根据《国家林业局关于加强农田防护林采伐更新管理的通知》(林资发〔2005〕217号)精神,结合我省实际,现就有关事项通知如下:一、农田防护林是指以保护农田,减轻自然灾害,改善生态环境,保证农业生产条件和促进农业稳产高产为主要目的的森林、林木。农田防护林采伐包括更新采伐、抚育采伐、低质低效林改造等3种。农田防护林采伐更新应坚持"因地制宜、分类管理。

Effects of thinning on microsites and natural regeneration in a Larix olgensis plantation in mountainous regions of eastern Liaoning Province, China

In order to understand the effects of thinning on microsite conditions and natural regeneration in the larch plantation, thinning experiment was conducted in a 40-year-old Larix olgensis plantation in Qingyuan County in eastern Liaoning Province, China in 2003-2004 Five thinning treatments （0%, 10.2%, 19.8%, 29.7% and 40.3% thinned） were designed on the same site. After thinning, canopy openness and the microsite conditions such as photosynthetic photon flux density （PPFD）, soil moisture content, and soil temperature were measured in one growing season. Meanwhile, the investigation of natural regeneration was conducted at the end of the growing season. The results showed that the canopy openness increased with the increase of thinning intensities. PPFD and soil temperature and soil moisture content in different soil layers were positively relative with canopy openness after thinning. The richness of regenerating tree species did not significantly increase （p=0.30） after one growing season since thinning, but the regeneration density and frequency of tree species increased significantly （p〈0.05）. In addition, the number of regenerating tree species increased, and the increment was correlated with the characteristics of iudividual tree species. The increasing percentage of regenerating seedlings of the shade-intolerant tree species was more than that of shade-tolerant tree species. Among the investigated regeneration species, the biggest response of seedling emergency to the canopy openness was Phellodendron amurense. This paper confirmed the following conclusions： after thinning, the variety of regenerating tree species was correlative with the characteristics of regenerating tree species, and the distribution of unthinned trees and the site conditions in the investigated larch plantation were the additional factors influencing, the regeneration.

Study on key techniques on ecological renovation design of existing buildings in China

With the rapid development of China economy and critical ecological situation in China,ecological renovation of existing buildings has become a special important topic. Key techniques on ecological renovation design of existing buildings in China are explored in this paper. Special attention is paid to specific treatments suitable for China.

The Late Pleistocene activity of the eastern part of east Kunlun fault zone and its tectonic significance

The nearly EW-trending East Kunlun fault zone is the north boundary of the Bayan Har block.The activity characteristics and the position of the eastern end of its eastward extension are of great significance to probing into the dynamic mechanism of formation of the east edge of the Tibetan Plateau,and also lay the foundation for seismic risk assessment of the fault zone.The following results are obtained by analysis based on satellite image interpretation of landforms,surface rupture survey,terrace scarp deformation survey,and terrace dating data on the eastern part of the East Kunlun fault zone:(1)the Luocha segment is a Holocene active fault,where a reverse L-shape paleoearthquake surface rupture zone of about 50 km long is located;(2)the Luocha segment is characterized by left-lateral slip movement under the compression-shear condition since the later period of the Late Pleistocene,with a rate of 7.68–9.37 mm/a and a vertical slip rate of 0.7–0.9 mm/a,which are basically in accord with the activity rate of segments on its west side.The results indicate that it is a part of eastward extension of the East Kunlun fault zone;(3)the high-speed linear horizontal slip of the nearly EW-trending East Kunlun fault zone is blocked by the South China block at east,and transforms into the vertical movement of the nearly SN-NNE trending Minjiang fault zone and the Longmenshan fault zone,and the uplift of Longmenshan and Minjiang.The area where transform of the two tectonic systems occurred confines the position of the east end;(4)Luocha segment and Maqu segment constitute the"Maqu seismic gap",so,seismic risk at Maqu segment is higher than that at Luocha segment,which should attract more attention.

Tectonically-controlled infilling of the eastern Nihewan Basin,North China,since the middle Pleistocene

There has been a significant debate about the nature and causes of the Pleistocene evolution of the Nihewan Basin, North China. We studied the eastern Nihewan Basin sedimentary facies at two main sites, Hutouliang and Donggou. A combination of field observations and measurements of sediment grain-size distribution was used to reconstruct the sequence of sedimentary environments since the middle Pleistocene, and optically-stimulated luminescence measurements were used to date the sediments. Our results indicate that a shallow lake occupied the basin center along the Sanggan River, probably lasting until -440 kyr ago before disappearing completely -340 kyr ago. It was succeeded by a phase of fluvial-dominated sediment accumulation which ended -30 kyr ago. We suggest that the formation of the gorge resulted from the relative uplift of the Niuxin Mountain along the Liulengshan fault -140 kyr ago. However, since -30 kyr ago the fault may have become inactive and the river downcutting near Shixia was no longer offset by the relative uplift, which caused a shift from deposition to denudation in the Nihewan Basin from then on. The disappearance of the paleolake -340 kyr ago may have been the culmination of the ongoing process of basin infilling.