Araucaria angustifolia is the dominant coniferous species in Brazil,a long-lived pioneer species and a supplier of valuable timber and non-timber products,which gives it key-species status.This study examines how A.an...Araucaria angustifolia is the dominant coniferous species in Brazil,a long-lived pioneer species and a supplier of valuable timber and non-timber products,which gives it key-species status.This study examines how A.angustifolia population structure affects the stand structure,and whether these relationships differ between protected and unprotected areas.The study was carried out on two protection status forests(national forest and urban forest)in a region of Atlantic mixed forest in ParanáState,southern Brazil.Skewness coefficient and the Weibull shape parameter described the population structure and its effects on species diversity and biomass stock.Population diameter distribution differed significantly between forests,with unbalanced structure in both,although regeneration was more abundant in the protected area.Skewness positively affected aboveground biomass whereas shape negatively affected it and species diversity.These relationships differed between protected and unprotected stands.The effect of A.angustifolia populations on stand structure was conditioned on protection status.Old-growth populations may have lower diversity and biomass stock even supporting large trees.Consequently,old-growth forests,can lead to wood loss through mortality,senescence,and declining populations,representing the waste of a valuable timber resource.These findings provide useful knowledge for forest management,species conservation,and the carbon market.展开更多
通过调查,对Araucaria cunninghamii和A.heterophylla的选模式和中国分类学文献(如《广州植物志》、《中国树木学》、《中国高等植物图鉴》、《中国植物志》、《中国树木志》、《Flora of China》、《中国高等植物》)的A.cunninghamii和...通过调查,对Araucaria cunninghamii和A.heterophylla的选模式和中国分类学文献(如《广州植物志》、《中国树木学》、《中国高等植物图鉴》、《中国植物志》、《中国树木志》、《Flora of China》、《中国高等植物》)的A.cunninghamii和A.heterophylla(或A.excelsa)作比较,证实中国分类学文献中的A.cunninghamii和A.heterophylla(或A.excelsa)分别是A.heterophylla(Salisb.)Franco和A.cunninghamii Aiton ex A.Cunn.。这两种植物的叶形变化较大,但有明显的区别:诺福克南洋杉A.heterophylla幼树的末级小枝的叶细长呈线形、叶尖急尖,生长角小于45°,腹面无明显的脊,成龄株的末级小枝的叶扁平呈鳞片状;南洋杉A.cunninghamii幼树的末级小枝的叶呈两侧扁的钻形、叶尖短刺状,生长角45°-90°,腹背两面具明显的脊,成龄株的末级小枝的叶呈四棱状钻形。展开更多
基金supported by the Conselho Nacional de Desenvolvimento Científico e Tecnológico–CNPq,by granting the scholarship to first author (Process:150288/2020-4)。
文摘Araucaria angustifolia is the dominant coniferous species in Brazil,a long-lived pioneer species and a supplier of valuable timber and non-timber products,which gives it key-species status.This study examines how A.angustifolia population structure affects the stand structure,and whether these relationships differ between protected and unprotected areas.The study was carried out on two protection status forests(national forest and urban forest)in a region of Atlantic mixed forest in ParanáState,southern Brazil.Skewness coefficient and the Weibull shape parameter described the population structure and its effects on species diversity and biomass stock.Population diameter distribution differed significantly between forests,with unbalanced structure in both,although regeneration was more abundant in the protected area.Skewness positively affected aboveground biomass whereas shape negatively affected it and species diversity.These relationships differed between protected and unprotected stands.The effect of A.angustifolia populations on stand structure was conditioned on protection status.Old-growth populations may have lower diversity and biomass stock even supporting large trees.Consequently,old-growth forests,can lead to wood loss through mortality,senescence,and declining populations,representing the waste of a valuable timber resource.These findings provide useful knowledge for forest management,species conservation,and the carbon market.
文摘通过调查,对Araucaria cunninghamii和A.heterophylla的选模式和中国分类学文献(如《广州植物志》、《中国树木学》、《中国高等植物图鉴》、《中国植物志》、《中国树木志》、《Flora of China》、《中国高等植物》)的A.cunninghamii和A.heterophylla(或A.excelsa)作比较,证实中国分类学文献中的A.cunninghamii和A.heterophylla(或A.excelsa)分别是A.heterophylla(Salisb.)Franco和A.cunninghamii Aiton ex A.Cunn.。这两种植物的叶形变化较大,但有明显的区别:诺福克南洋杉A.heterophylla幼树的末级小枝的叶细长呈线形、叶尖急尖,生长角小于45°,腹面无明显的脊,成龄株的末级小枝的叶扁平呈鳞片状;南洋杉A.cunninghamii幼树的末级小枝的叶呈两侧扁的钻形、叶尖短刺状,生长角45°-90°,腹背两面具明显的脊,成龄株的末级小枝的叶呈四棱状钻形。
