The effect of litter on forest regeneration depends on the characteristics of regional climate and also shows community specificity. The influences of plant litter on seed germination and seedling growth of Larch Sibe...The effect of litter on forest regeneration depends on the characteristics of regional climate and also shows community specificity. The influences of plant litter on seed germination and seedling growth of Larch Siberian forest in the Altai Mountains were investigated through two simulated experiments including litter coverage and litter aqueous extracts. In the litter coverage experiment, three litter coverage methods including above (D), below (S) and in the middle (Z) of litter were set with the litter coverage thickness of 0, 1, 2, and 4 cm, while two aqueous extract obtained methods using the air-dried litter and litter ash after fir were used with the concentration of 10%, 40%, 80% and 100% in the present study. Results showed that: the aqueous extracts obtained using the air-dried litter restrained the seed germination, while the aqueous extracts obtained using litter ash improved the seed germination. Compared with other litter concentration, the influences of 100% concentration reach highest. The seed germination rate, seed germination potential and vital index under the treatment of seeds above the litter coverage were highest, which were significantly higher than other treatments. The above-ground biomass was significantly higher and the inhibition index of below-ground bio-mass was significantly lower under the treatment of seed above the litter with thin litter cover-age (S1) compared to other litter coverage treatments. These results indicated that the litter aqueous extract and the litter coverage had a combined effect on the seed germination and seedling growth of Siberian larch forest. Fire disturbance could promote seed germination by modifying the adverse effects of litter aqueous extracts and litter coverage, and thus plays an important role in the regeneration of Siberian larch in the Altai Mountains.展开更多
We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood ...We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood and erosion control works. The drainage basins were chosen because of their severe damage by fire, post-fire potential for erosion and flood due to the steep relief, and the importance of the area for residential and tourism development. The first measures taken in the area after the fire were salvage cutting of burned trees, a total ban on grazing, and construction of three types of works, log erosion barriers（LEBs）, log check dams and contour branch barriers. Almost all necessary post-fire works were completed in both catchments but many construction failures were recorded. Approximately 75 % of the LEBs and45 % of the contour branch barriers functioned properly,while the remainder failed. Nearly 80 % of the log dams were sedimented to 0–20 % of the dam height, 14.3 %were 20–40 % filled and 5.9 % collapsed. Despite these failures, peak discharge declined by 10.5 % in Chanioti and 20.4 % in N. Skioni catchment. The main reasons for works failures were the rush of construction and the limited supervision of workers, which resulted in floods during the years that followed.展开更多
文摘The effect of litter on forest regeneration depends on the characteristics of regional climate and also shows community specificity. The influences of plant litter on seed germination and seedling growth of Larch Siberian forest in the Altai Mountains were investigated through two simulated experiments including litter coverage and litter aqueous extracts. In the litter coverage experiment, three litter coverage methods including above (D), below (S) and in the middle (Z) of litter were set with the litter coverage thickness of 0, 1, 2, and 4 cm, while two aqueous extract obtained methods using the air-dried litter and litter ash after fir were used with the concentration of 10%, 40%, 80% and 100% in the present study. Results showed that: the aqueous extracts obtained using the air-dried litter restrained the seed germination, while the aqueous extracts obtained using litter ash improved the seed germination. Compared with other litter concentration, the influences of 100% concentration reach highest. The seed germination rate, seed germination potential and vital index under the treatment of seeds above the litter coverage were highest, which were significantly higher than other treatments. The above-ground biomass was significantly higher and the inhibition index of below-ground bio-mass was significantly lower under the treatment of seed above the litter with thin litter cover-age (S1) compared to other litter coverage treatments. These results indicated that the litter aqueous extract and the litter coverage had a combined effect on the seed germination and seedling growth of Siberian larch forest. Fire disturbance could promote seed germination by modifying the adverse effects of litter aqueous extracts and litter coverage, and thus plays an important role in the regeneration of Siberian larch in the Altai Mountains.
文摘We quantified morphological and hydrographical characteristics of two drainage basins（Chanioti and N. Skioni） on Cassandra peninsula of Chalkidiki（North Greece）, and evaluated the effectiveness of post-fire flood and erosion control works. The drainage basins were chosen because of their severe damage by fire, post-fire potential for erosion and flood due to the steep relief, and the importance of the area for residential and tourism development. The first measures taken in the area after the fire were salvage cutting of burned trees, a total ban on grazing, and construction of three types of works, log erosion barriers（LEBs）, log check dams and contour branch barriers. Almost all necessary post-fire works were completed in both catchments but many construction failures were recorded. Approximately 75 % of the LEBs and45 % of the contour branch barriers functioned properly,while the remainder failed. Nearly 80 % of the log dams were sedimented to 0–20 % of the dam height, 14.3 %were 20–40 % filled and 5.9 % collapsed. Despite these failures, peak discharge declined by 10.5 % in Chanioti and 20.4 % in N. Skioni catchment. The main reasons for works failures were the rush of construction and the limited supervision of workers, which resulted in floods during the years that followed.
