Terrestrial ecosystems represent a major sink for atmospheric carbon(C) and temperate forests play an important role in global C cycling, contributing to lower atmospheric carbon dioxide(CO2) concentration through pho...Terrestrial ecosystems represent a major sink for atmospheric carbon(C) and temperate forests play an important role in global C cycling, contributing to lower atmospheric carbon dioxide(CO2) concentration through photosynthesis. The Intergovernmental Panel of Climate Change highlights that the forestry sector has great potential to decrease atmospheric CO2concentration compared to other sectoral mitigation activities. The aim of this study was to evaluate CO2sequestration(CO2S)capability of Fag us sylvatica(beech) growing in the Orfento Valley within Majella National Park(Abruzzo,Italy). We compared F. sylvatica areas subjected to thinning(one high-forest and one coppice) and no-management areas(two high-forests and two coppices). The results show a mean CO2S of 44.3 ± 2.6 Mg CO2ha-1a-1,corresponding to 12.1 ± 0.7 Mg C ha-1a-1the no-managed areas having a 28% higher value than the managed areas. The results highlight that thinning that allows seed regeneration can support traditional management practices such as civic use in some areas while no management should be carried out in the reserve in order to give priority to the objective of conservation and naturalistic improvement of the forest heritage.展开更多
Aims With a close association with plant water availability,foliar δ^(13)C had been investigated extensively in alpine regions;however,foliar δ^(15)N has rarely been concurrently used as an indicator of plant nitrog...Aims With a close association with plant water availability,foliar δ^(13)C had been investigated extensively in alpine regions;however,foliar δ^(15)N has rarely been concurrently used as an indicator of plant nitrogen availability.Due to the positive correlations between leaf nitrogen con-tent and foliar δ^(13)C andδ15N found in previous studies,we expected that they should show consistent patterns along an altitudinal gradient.Methods To test our hypothesis,we measured foliar δ^(13)C andδ15N in conjunc-tion with multiple key leaf functional traits of Quercus aquifolioides,a dominant species of alpine forest on the eastern slopes of the sygera mountains,southeastern Tibetan Plateau from 2500 to 3800 m.Important findings(i)Contrary to our hypothesis,foliar δ^(13)C exhibited a significant pos-itive linear relationship with altitude;in contrast,foliarδ15N initially increased and subsequently decreased with altitude,the change in trend occurring around 3300 m.(ii)our analyses indicated that leaf internal resistance and stomatal conductance,rather than photosynthetic capacity indicated by leaf N concentration,appar-ently explained the altitudinal variation in foliar δ^(13)C,while differ-ences in foliar δ^(15)N were likely the result of soil N availability.(iii)Principal component analysis revealed a clear association between δ^(13)C and a tradeoff between water loss and carbon gain,indicated by traits related to gas exchange such as leaf thickness,density,sto-matal properties.In contrast,the second axis was associated withδ15N and nitrogen acquisition strategy in Q.aquifolioides across its altitudinal distribution,represented by traits related to nitrogen concentration and stomata per gram of leaf nitrogen.展开更多
文摘Terrestrial ecosystems represent a major sink for atmospheric carbon(C) and temperate forests play an important role in global C cycling, contributing to lower atmospheric carbon dioxide(CO2) concentration through photosynthesis. The Intergovernmental Panel of Climate Change highlights that the forestry sector has great potential to decrease atmospheric CO2concentration compared to other sectoral mitigation activities. The aim of this study was to evaluate CO2sequestration(CO2S)capability of Fag us sylvatica(beech) growing in the Orfento Valley within Majella National Park(Abruzzo,Italy). We compared F. sylvatica areas subjected to thinning(one high-forest and one coppice) and no-management areas(two high-forests and two coppices). The results show a mean CO2S of 44.3 ± 2.6 Mg CO2ha-1a-1,corresponding to 12.1 ± 0.7 Mg C ha-1a-1the no-managed areas having a 28% higher value than the managed areas. The results highlight that thinning that allows seed regeneration can support traditional management practices such as civic use in some areas while no management should be carried out in the reserve in order to give priority to the objective of conservation and naturalistic improvement of the forest heritage.
基金This research was supported by the Program for New Century Excellent Talents in University(NCET-08-0257)the National Natural Science Foundation of China(30972337,30930072 and 31170571)Fundamental Research Funds for the Central Universities(lzujbky-2010-47 and lzujbky-2012-k20)。
文摘Aims With a close association with plant water availability,foliar δ^(13)C had been investigated extensively in alpine regions;however,foliar δ^(15)N has rarely been concurrently used as an indicator of plant nitrogen availability.Due to the positive correlations between leaf nitrogen con-tent and foliar δ^(13)C andδ15N found in previous studies,we expected that they should show consistent patterns along an altitudinal gradient.Methods To test our hypothesis,we measured foliar δ^(13)C andδ15N in conjunc-tion with multiple key leaf functional traits of Quercus aquifolioides,a dominant species of alpine forest on the eastern slopes of the sygera mountains,southeastern Tibetan Plateau from 2500 to 3800 m.Important findings(i)Contrary to our hypothesis,foliar δ^(13)C exhibited a significant pos-itive linear relationship with altitude;in contrast,foliarδ15N initially increased and subsequently decreased with altitude,the change in trend occurring around 3300 m.(ii)our analyses indicated that leaf internal resistance and stomatal conductance,rather than photosynthetic capacity indicated by leaf N concentration,appar-ently explained the altitudinal variation in foliar δ^(13)C,while differ-ences in foliar δ^(15)N were likely the result of soil N availability.(iii)Principal component analysis revealed a clear association between δ^(13)C and a tradeoff between water loss and carbon gain,indicated by traits related to gas exchange such as leaf thickness,density,sto-matal properties.In contrast,the second axis was associated withδ15N and nitrogen acquisition strategy in Q.aquifolioides across its altitudinal distribution,represented by traits related to nitrogen concentration and stomata per gram of leaf nitrogen.
