Background: After their death, Scots pine trees can remain standing for decades and sometimes up to 200 years,forming long-lasting and ecologically important structures in boreal forest landscapes. Standing dead pines...Background: After their death, Scots pine trees can remain standing for decades and sometimes up to 200 years,forming long-lasting and ecologically important structures in boreal forest landscapes. Standing dead pines decay very slowly and with time develop into ‘kelo' trees, which are characterized by hard wood with silvery-colored appearance. These kelo trees represent an ecologically important, long lasting and visually striking element of the structure of natural pine-dominated forests in boreal Fennoscandia that is nowadays virtually absent from managed forest landscapes.Methods: We examined and mapped the amount, structural features, site characteristics and spatial distribution of dead standing pine trees over a ten hectare area in an unmanaged boreal forest landscape in the Kalevala National Park in Russian Viena Karelia.Results: The mean basal area of dead standing pine trees in the forested part of the landscape was 1.7 m^2?ha^(-1) and the estimated volume 12.7 m^3?ha^(-1). From the total number of standing dead pine trees 65% were kelo trees, with a basal area of 1.1 m^2?ha^(-1) and volume of 8.0 m^3?ha^(-1), the remainder consisting of standing dead pines along the continuum between a recently dead tree and a kelo tree. Overall, standing dead pines were distributed throughout the study area, but there was a tendency towards spatial clustering up to <100 m distances. Standing dead pines were most commonly situated on flat ground or in the mid slope in the local topography.In addition, standing dead pines contributed to substrate diversity also by commonly having charred wood and broken tops. Based on the presence of dead pine snags in different stage of transition from a recently dead pine to a kelo with silvery surface, it seems evident that the process of kelo recruitment was continuously in action in the studied landscape.Conclusions: Kelo trees are an omnipresent feature in natural pine-dominated forest landscapes with important contribution to forest structural and substrate diversity. Because of their longevity and extremely slow turnover dynamics and importance for biodiversity, protection of vulnerable kelo tree populations, and ensuring their continuous recruitment, should be of high priority in forest restoration and sustainable management.展开更多
Bacillus megaterium as a companion strain in two-stage fermentation of vitamin Ccould secrete some active substances to spur growth of Gluconobacter oxydans to produce 2-KLG.In the fermenting system where Gluconobacte...Bacillus megaterium as a companion strain in two-stage fermentation of vitamin Ccould secrete some active substances to spur growth of Gluconobacter oxydans to produce 2-KLG.In the fermenting system where Gluconobacter oxydans was combined with GB82-a mutatedstrain of B. megaterium by ion implantation, the amount of 2-KLG harvested was larger thanthat produced by the original B. megaterium BP52[1] being substituted for GB82. In this paper,we studied the effect of the active substances secreted by GB82 to enhance the capability ofGluconobacter oxydans to produce 2-KLG. The supernate of GB82 sampled at different cultivationtimes all had much more activity to spur Gluconobacter oxydans to yield 2-KLG than that of theoriginal B. megaterium, which might be due to the genetic changes in the active componentscaused by ion implantation. Furthermore, the active substances of GB82's supernate would losea part of its activity in extreme environments, which is typical of some proteins.展开更多
基金the EBOR-project funded by the Academy of Finland (proj.no.276255)
文摘Background: After their death, Scots pine trees can remain standing for decades and sometimes up to 200 years,forming long-lasting and ecologically important structures in boreal forest landscapes. Standing dead pines decay very slowly and with time develop into ‘kelo' trees, which are characterized by hard wood with silvery-colored appearance. These kelo trees represent an ecologically important, long lasting and visually striking element of the structure of natural pine-dominated forests in boreal Fennoscandia that is nowadays virtually absent from managed forest landscapes.Methods: We examined and mapped the amount, structural features, site characteristics and spatial distribution of dead standing pine trees over a ten hectare area in an unmanaged boreal forest landscape in the Kalevala National Park in Russian Viena Karelia.Results: The mean basal area of dead standing pine trees in the forested part of the landscape was 1.7 m^2?ha^(-1) and the estimated volume 12.7 m^3?ha^(-1). From the total number of standing dead pine trees 65% were kelo trees, with a basal area of 1.1 m^2?ha^(-1) and volume of 8.0 m^3?ha^(-1), the remainder consisting of standing dead pines along the continuum between a recently dead tree and a kelo tree. Overall, standing dead pines were distributed throughout the study area, but there was a tendency towards spatial clustering up to <100 m distances. Standing dead pines were most commonly situated on flat ground or in the mid slope in the local topography.In addition, standing dead pines contributed to substrate diversity also by commonly having charred wood and broken tops. Based on the presence of dead pine snags in different stage of transition from a recently dead pine to a kelo with silvery surface, it seems evident that the process of kelo recruitment was continuously in action in the studied landscape.Conclusions: Kelo trees are an omnipresent feature in natural pine-dominated forest landscapes with important contribution to forest structural and substrate diversity. Because of their longevity and extremely slow turnover dynamics and importance for biodiversity, protection of vulnerable kelo tree populations, and ensuring their continuous recruitment, should be of high priority in forest restoration and sustainable management.
文摘Bacillus megaterium as a companion strain in two-stage fermentation of vitamin Ccould secrete some active substances to spur growth of Gluconobacter oxydans to produce 2-KLG.In the fermenting system where Gluconobacter oxydans was combined with GB82-a mutatedstrain of B. megaterium by ion implantation, the amount of 2-KLG harvested was larger thanthat produced by the original B. megaterium BP52[1] being substituted for GB82. In this paper,we studied the effect of the active substances secreted by GB82 to enhance the capability ofGluconobacter oxydans to produce 2-KLG. The supernate of GB82 sampled at different cultivationtimes all had much more activity to spur Gluconobacter oxydans to yield 2-KLG than that of theoriginal B. megaterium, which might be due to the genetic changes in the active componentscaused by ion implantation. Furthermore, the active substances of GB82's supernate would losea part of its activity in extreme environments, which is typical of some proteins.
