We hypothesize that in mountain windy habitat trees formed clusters(hedges)as adaptive structures for seedlings’rooting,survival,and tress’upslope migration.We studied hedges formed by Siberian pine(Pinus sibirica d...We hypothesize that in mountain windy habitat trees formed clusters(hedges)as adaptive structures for seedlings’rooting,survival,and tress’upslope migration.We studied hedges formed by Siberian pine(Pinus sibirica du Tour)and larch(Larix sibirica Ledeb.)within the treeline ecotone in southern Siberian Mountains,investigated hedges formation,evolution,habitat amelioration,and analyzed tree’s growth index(GI)dependence on the eco-climate variables(air temperature,precipitation,soil moisture,wind speed)and relief features(elevation,aspect,slope steepness,and terrain curvature).We conducted a ground survey,measured biometrical parameters of trees and hedges,determined species composition and tree physiognomy,soil types and nutrient contents,and sampled wood cores and applied dendrochronology for trees’GI analysis.With high-resolution satellite scenes for hedge detection and upslope migration,we found that winter winds and soil moisture are the main constraints of trees’settlement and growth.Hedge formation always links with wind-sheltered microtopography features(boulders,local depressions or felled trees).Once the first tree is established,a positive feedback is aroused that facilitates seedling rooting and in-hedge habitat amelioration.Trees form a streamlined dense“common crown”that mitigates adverse winter wind influence.Hedges always orient along the prevailing winds,and trees’uphill migration occurs by seedlings establishment within the leeward hedge side.Hedge growth facilitates soil formation and fertilization.The concentration of nutrients(K,P,N and S)within hedges exceeds the background by 1.5-5.5 times.Hedge extension leads to increased snow accumulation that mitigates the influence of desiccation and snow abrasion and mitigates seasonal water stress.In the extremely harsh windy habitat,inhedge trees present in mat,prostrate or krummholz forms.With warming,tree stems and even twigs turn upright.Notably that GI dependence on the wind speed is insignificant until prostrated trees get turning upright.Since that,the negative correlation between GI and wind speed is arisen with subsequent decrease since hedges form streamlined crown.Hedge growth also leads to a“phytofield”formation(i.e.,grasses,lichen,moss and small bushes growth)around the hedges that,in its turn,encourages seedling rooting which is about triple more efficient than outside the phytofield.Larch,in comparison with Siberian pine,is less often formed hedges.GI of both species is stimulated by warmer air temperature in the beginning of the growth season.Meanwhile,larch GI has stronger response to elevated temperatures and less dependent on soil moisture.This indicates larch is a potential substitute of Siberian pine in a warmer and dryer climate.Hedges in warming climate evolve into closed stands due to both in-hedge tree growth and filling gaps between hedges by different tree species.展开更多
The growth,survival,and mortality of conifer species in response to the hydrothermal regime have received considerable attention.It is expected that the highest sensitivity of trees to the warming-drying climate will ...The growth,survival,and mortality of conifer species in response to the hydrothermal regime have received considerable attention.It is expected that the highest sensitivity of trees to the warming-drying climate will occur mainly at the edges of the species ranges.We focused on the responses to climate change of the drought-resistant larch(Larix sibirica)and the moisture-sensitive Siberian pine(Pinus sibirica)along the elevation gradient in the Tannu-Ola Ridge,the southern margin where those two species coexist in Siberia by using satellite data(MODIS,Landsat,and microwave),the indexes of gross(GPP)and net(NPP)primary productivity,and tree radial growth index(GI).We found that since the warming restart in the 2000s,the area of larch-dominated forests increased by~150%while the area of pine-dominated forests decreased by~10%.The Siberian pine has retreated at low elevations(<1800 m)and increased its area at higher ones.In contrast,the area of larch stands increased in both the uphill and downhill directions.Birch(Betula spp.)also increased its area at low elevations(about+120%).Since 2001,the forested area increased by~5%.A shrubification,i.e.,an increase in the area of shrubs,was observed at high elevations.The uphill rate of timberline and shrubline migration was about 0.3 m/a.Since the 2000s,vegetation NPP has increased by 13%.A notable correlation between NPP and the GI of larch and pine was found(r=0.5-0.7).At lower elevations,NPP positively correlated with precipitation and soil moisture,while air temperature and VPD(vapor pressure deficit)increase inhibited productivity.At high elevations,the effects of these variables on productivity reversed.The continuous decline of the Siberian pine forest indicates an inevitable retreat of this species at low elevations and its replacement by larch and birch.展开更多
Responding to the predicted shift in climate envelope jack pine, (Pinus banksiana Lamb.) might migrate 10° northward between 2071 and 2100 and will be exposed to a different photoperiod regime. Successful migrati...Responding to the predicted shift in climate envelope jack pine, (Pinus banksiana Lamb.) might migrate 10° northward between 2071 and 2100 and will be exposed to a different photoperiod regime. Successful migration of the species might depend on the initial acclimating capability to the conditions of new location. The impacts of elevated carbon dioxide concentration [CO<sub>2</sub>], soil temperature and photoperiod on the phenological traits, growth and biomass responses in jack pine seedlings were investigated. Seedlings were grown in greenhouses under two [CO<sub>2</sub>] (400 and 950 μmol•mol<sup>-1</sup>), two soil temperatures (ambient soil temperature at seed origin and 5°C warmer) and three photoperiod regimes (photoperiods at seed origin, 5° north of the seed origin and 10° north of the seed origin). Budburst and bud setting time were recorded and the seedling height (Ht), root collar diameter (RCD), root biomass, stem biomass and leaf biomass were measured after six months of treatment. It was observed that under elevated [CO<sub>2</sub>], ambient T<sub>soil</sub> and photoperiods associated with 10° northward migrations budburstis advanced by 10 days. Photoperiods toward north significantly prolonged the bud setting time. However, tri-factor interactive effect on bud set was not statistically significant. Elevated [CO<sub>2</sub>] significantly (P < 0.05) increased the RCD, volume of the seedlings and total biomass and longer growing season photoperiods towards north significantly increased the seedling heights. Though elevated [CO<sub>2</sub>] significantly increased the projected leaf area, it had no significant effect on specific leaf area. Elevated [CO<sub>2</sub>] significantly reduced the shoot to root ratio, which indicated higher biomass allocation in roots under elevated [CO<sub>2</sub>]. However, all these growth and biomass responses were statistically insignificant under tri-factor interactive effects. The results suggest that climate change induced northward migration will not affect the growth of jack pine. However, a long distance migration (e.g. 10° north) will expose the species to late-spring frost damage.展开更多
基金The Tomsk State University Development Program(《Priority-2030》)。
文摘We hypothesize that in mountain windy habitat trees formed clusters(hedges)as adaptive structures for seedlings’rooting,survival,and tress’upslope migration.We studied hedges formed by Siberian pine(Pinus sibirica du Tour)and larch(Larix sibirica Ledeb.)within the treeline ecotone in southern Siberian Mountains,investigated hedges formation,evolution,habitat amelioration,and analyzed tree’s growth index(GI)dependence on the eco-climate variables(air temperature,precipitation,soil moisture,wind speed)and relief features(elevation,aspect,slope steepness,and terrain curvature).We conducted a ground survey,measured biometrical parameters of trees and hedges,determined species composition and tree physiognomy,soil types and nutrient contents,and sampled wood cores and applied dendrochronology for trees’GI analysis.With high-resolution satellite scenes for hedge detection and upslope migration,we found that winter winds and soil moisture are the main constraints of trees’settlement and growth.Hedge formation always links with wind-sheltered microtopography features(boulders,local depressions or felled trees).Once the first tree is established,a positive feedback is aroused that facilitates seedling rooting and in-hedge habitat amelioration.Trees form a streamlined dense“common crown”that mitigates adverse winter wind influence.Hedges always orient along the prevailing winds,and trees’uphill migration occurs by seedlings establishment within the leeward hedge side.Hedge growth facilitates soil formation and fertilization.The concentration of nutrients(K,P,N and S)within hedges exceeds the background by 1.5-5.5 times.Hedge extension leads to increased snow accumulation that mitigates the influence of desiccation and snow abrasion and mitigates seasonal water stress.In the extremely harsh windy habitat,inhedge trees present in mat,prostrate or krummholz forms.With warming,tree stems and even twigs turn upright.Notably that GI dependence on the wind speed is insignificant until prostrated trees get turning upright.Since that,the negative correlation between GI and wind speed is arisen with subsequent decrease since hedges form streamlined crown.Hedge growth also leads to a“phytofield”formation(i.e.,grasses,lichen,moss and small bushes growth)around the hedges that,in its turn,encourages seedling rooting which is about triple more efficient than outside the phytofield.Larch,in comparison with Siberian pine,is less often formed hedges.GI of both species is stimulated by warmer air temperature in the beginning of the growth season.Meanwhile,larch GI has stronger response to elevated temperatures and less dependent on soil moisture.This indicates larch is a potential substitute of Siberian pine in a warmer and dryer climate.Hedges in warming climate evolve into closed stands due to both in-hedge tree growth and filling gaps between hedges by different tree species.
基金supported by the Tomsk State University Development Program(《Priority-2030》)the Basic Project of the Federal Research Center of the Scientific Center,no.FWES-2024-0023the Russian Science Foundation(project No.23-14-20015)。
文摘The growth,survival,and mortality of conifer species in response to the hydrothermal regime have received considerable attention.It is expected that the highest sensitivity of trees to the warming-drying climate will occur mainly at the edges of the species ranges.We focused on the responses to climate change of the drought-resistant larch(Larix sibirica)and the moisture-sensitive Siberian pine(Pinus sibirica)along the elevation gradient in the Tannu-Ola Ridge,the southern margin where those two species coexist in Siberia by using satellite data(MODIS,Landsat,and microwave),the indexes of gross(GPP)and net(NPP)primary productivity,and tree radial growth index(GI).We found that since the warming restart in the 2000s,the area of larch-dominated forests increased by~150%while the area of pine-dominated forests decreased by~10%.The Siberian pine has retreated at low elevations(<1800 m)and increased its area at higher ones.In contrast,the area of larch stands increased in both the uphill and downhill directions.Birch(Betula spp.)also increased its area at low elevations(about+120%).Since 2001,the forested area increased by~5%.A shrubification,i.e.,an increase in the area of shrubs,was observed at high elevations.The uphill rate of timberline and shrubline migration was about 0.3 m/a.Since the 2000s,vegetation NPP has increased by 13%.A notable correlation between NPP and the GI of larch and pine was found(r=0.5-0.7).At lower elevations,NPP positively correlated with precipitation and soil moisture,while air temperature and VPD(vapor pressure deficit)increase inhibited productivity.At high elevations,the effects of these variables on productivity reversed.The continuous decline of the Siberian pine forest indicates an inevitable retreat of this species at low elevations and its replacement by larch and birch.
文摘Responding to the predicted shift in climate envelope jack pine, (Pinus banksiana Lamb.) might migrate 10° northward between 2071 and 2100 and will be exposed to a different photoperiod regime. Successful migration of the species might depend on the initial acclimating capability to the conditions of new location. The impacts of elevated carbon dioxide concentration [CO<sub>2</sub>], soil temperature and photoperiod on the phenological traits, growth and biomass responses in jack pine seedlings were investigated. Seedlings were grown in greenhouses under two [CO<sub>2</sub>] (400 and 950 μmol•mol<sup>-1</sup>), two soil temperatures (ambient soil temperature at seed origin and 5°C warmer) and three photoperiod regimes (photoperiods at seed origin, 5° north of the seed origin and 10° north of the seed origin). Budburst and bud setting time were recorded and the seedling height (Ht), root collar diameter (RCD), root biomass, stem biomass and leaf biomass were measured after six months of treatment. It was observed that under elevated [CO<sub>2</sub>], ambient T<sub>soil</sub> and photoperiods associated with 10° northward migrations budburstis advanced by 10 days. Photoperiods toward north significantly prolonged the bud setting time. However, tri-factor interactive effect on bud set was not statistically significant. Elevated [CO<sub>2</sub>] significantly (P < 0.05) increased the RCD, volume of the seedlings and total biomass and longer growing season photoperiods towards north significantly increased the seedling heights. Though elevated [CO<sub>2</sub>] significantly increased the projected leaf area, it had no significant effect on specific leaf area. Elevated [CO<sub>2</sub>] significantly reduced the shoot to root ratio, which indicated higher biomass allocation in roots under elevated [CO<sub>2</sub>]. However, all these growth and biomass responses were statistically insignificant under tri-factor interactive effects. The results suggest that climate change induced northward migration will not affect the growth of jack pine. However, a long distance migration (e.g. 10° north) will expose the species to late-spring frost damage.
