This study aimed to decipher the mechanism by which exogenous methyl jasmonate(MeJA)regulated the photosynthesis of Malus spectabilis leaves under ozone(O_(3))stress.The photosynthetic parameters and chlorophyll fluor...This study aimed to decipher the mechanism by which exogenous methyl jasmonate(MeJA)regulated the photosynthesis of Malus spectabilis leaves under ozone(O_(3))stress.The photosynthetic parameters and chlorophyll fluorescence parameters of M.spectabilis‘Hongjiu’seedlings under O_(3)stress were measured by spraying different concentrations of MeJA.The results showed that O_(3)stress significantly reduced the chlorophyll a and total chlorophyll content,net photosynthetic rate(Pn),stomatal conductance(G_(s)),transpiration rate(T_(r)),maximum fluorescence yield(F_(m)),maximum quantum yield of photosystem II(F_(v)/F_(m)),and actual photochemical efficiency of photosystem II(Ф_(PSII)),while increasing the intercellular CO_(2)concentration(Ci).Exogenous MeJA reduced the Ci and original fluorescence yield(Fo),while increasing chlorophyll a,chlorophyll b,and total chlorophyll content,P_(n),G_(s),T_(r),F_(m),F_(v)/F_(m),andФ_(PSII) of the leaves under O_(3)stress.The application of 150μmol/L MeJA showed the best effect.The above results demonstrated that exogenous MeJA could enhance chlorophyll content and photosynthetic capacity,thereby improving the tolerance of M.spectabilis to O_(3)stress.展开更多
Spectasterols F−O(1−10),ten interesting ergosterols with an aromatized B ring,were obtained from Aspergillus spectabilis.Their structures and absolute configurations were determined using a combination of high-resolut...Spectasterols F−O(1−10),ten interesting ergosterols with an aromatized B ring,were obtained from Aspergillus spectabilis.Their structures and absolute configurations were determined using a combination of high-resolution electrospray ionization mass spectrometry(HR-ESI-MS),nuclear magnetic resonance(NMR)spectroscopy,single-crystal X-ray diffraction analyses,and electronic circular dichroism(ECD)calculations.Structurally,these aromatic ergosterols feature versatile side chains.Notably,compound aromatic ergosterols featured versatile side chains,and compound 4 is an unusual C23 ergosterol characterized by a shorter side chain due to oxidative cleavage between C-23 and C-24.All compounds were evaluated for their neuroprotective activities,with compound 8 showing a dose-dependent ability to reduce apoptosis and protect mitochondrial function in glutamate-induced SH-SY5Y cells.展开更多
[Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects...[Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects of remaining leaf combining with IBA on rooting,physiological and biochemical indicators of B.spectabilis cuttings were studied under the regulation and control of intelligent seed propagation system,and then set four treatments：remaining leaf combining with soaking in clean water,remaining leaf combining with soaking in IBA,defoliation combining soaking in clean water,and defoliation combining with soaking in IBA.[Result] The soluble sugar content was high,but indoleacetic acid oxidase activity was lower in the initial stage of adventitious root differentiation in treatment of remaining leaf.While the rooting number,root length,the root mass growth and survival rate of cutting were obviously higher than that in treatment of defoliation.Compared to the treatment soaking in clean water,the treatment soaking in 500×10^-6 IBA increased the soluble sugar content in leaves of cuttings and enhanced rooting of cuttings.[Conclusion] The survival rate and rooting of cuttings improved obviously in the treatment of remaining leaf combining with soaking in 500×10^-6 IBA before cutting under the regulation and control of intelligent seed propagation system.展开更多
A dendroclimatic study was conducted in the treeline ecotone of Barun Valley, eastern Nepal, to determine the tree-ring climate response and ring width trend of Abies spectabilis. A 160-year-old chronology, from 1850 ...A dendroclimatic study was conducted in the treeline ecotone of Barun Valley, eastern Nepal, to determine the tree-ring climate response and ring width trend of Abies spectabilis. A 160-year-old chronology, from 1850 to 2010, was developed from 38 tree-ring samples. No higher growth in recent decades was observed in tree-ring width in this area. The mean temperature of the current year in February and in the combined winter months of December, January, and February showed significant positive correlation with tree-ring width, although no significant correlation was found between tree-ring width and the precipitation pattern of the region. This tree-ring climate response result is different from that in other studies in Nepal, which could be attributed to location and elevation.展开更多
The Himalayas are characterized by a broad gradient of bioclimatic zones along their elevation.However,less is known how forest growth responds to climatic change along elevation.In this study,four standard treering w...The Himalayas are characterized by a broad gradient of bioclimatic zones along their elevation.However,less is known how forest growth responds to climatic change along elevation.In this study,four standard treering width chronologies of Himalayan fir(Abies spectabilis)were developed,spanning 142–649 years along an elevation gradient of 3076–3900 m a.s.l.Principal component analysis classified the four chronologies into two groups;the ones at lower elevations(M1 and M2)and higher elevations(M3 and M4)show two distinct growth trends.Radial growth is limited by summer(June–August)precipitation at M3,and by precipitation during spring(March–May)and summer at M4.It is limited by spring temperatures and winter precipitation(December–February)at M1.Tree-ring width chronologies also significantly correlate with winter and spring Palmer Drought Severity Index(PDSI)at M1,and with summer PDSI at M3 and M4.Thus,Himalayan fir growth at high elevations is mainly limited by moisture stress rather than by low temperatures.Furthermore,the occurrence of missing rings coincides with dry periods,providing additional evidence for moisture limitation of Himalayan fir growth.展开更多
Objective:To investigate the effect of two extracts of Bougainvillea spectabilis(B. spectabilis) flowers with yellow and pink/purple on brain oxidative stress and neuronal damage caused in rats by systemic rotenone in...Objective:To investigate the effect of two extracts of Bougainvillea spectabilis(B. spectabilis) flowers with yellow and pink/purple on brain oxidative stress and neuronal damage caused in rats by systemic rotenone injection. Methods:Rotenone 1.5 mg/kg was given three times per week alone or in combination with B. spectabilis flowers extracts(25 mg or 50 mg) via the subcutaneous route for 2 weeks. Brain concentrations of the lipid peroxidation marker malondialdehyde(MDA),reduced glutathione,nitric oxide(nitrite),the pro-inflammatory cytokine interleukin-1beta(Il-1β) as well as butyrylcholinesterase,and paraoxonase-1(PON-1) activities,were determined. Histopathology and caspase-3 immunohistochemistry were also performed. Results:Rotenone resulted in significant increases of brain MDA(the product of lipid peroxidation),and nitric oxide content along with decreased brain reduced glutathione. There were also marked and significant inhibition of brain PON-1 and BCh E activities and increased Il-1β in brain of rotenone-treated rats. B. spectabilis flowers extract itself resulted in brain oxidative stress increasing both lipid peroxidation and nitrite content whilst inhibiting PON-1 activity. The yellow flowers extract inhibited BCh E activity and increased brain Il-1β. When given to rotenone-treated rats,B. spectabilis extracts,however,decreased lipid peroxidation while their low administered doses increased brain GSH. Brain nitrite decreased by the pink extract but showed further increase by the yellow extract. Either extract,however,caused further inhibition of PON-1 activity while the yellow extract resulted in further inhibition of BChE activity. Histopathological studies indicated that both extracts protected against brain,liver and kidney damage caused by the toxicant. Conclusions:These data indicate that B. spectabilis flowers extracts exert protective effect against the toxic effects of rotenone on brain,liver and kidney. B. spectabilis flowers extracts decreased brain lipid peroxidation and prevented neuronal death due to rotenone and might thus prove the value in treatment of Parkinson's disease.展开更多
The long-legged chafer Hoplia spectabilis Medvedev was described in 1952. Its occurrence was rarely reported and the document about its morphological details was not found. However, the chafer did frequently break out...The long-legged chafer Hoplia spectabilis Medvedev was described in 1952. Its occurrence was rarely reported and the document about its morphological details was not found. However, the chafer did frequently break out at Buha River valley in Tianjun county, Qinghai province, China since 2005. In this paper, we present a comprehensive description and illustrations of morphological characteristics of H. spectabilis from local collection, including developmental stages of adult, egg, larva and pupa. Among them, characteristics of the larva and pupa, the male genitalia as well as the difference between male and female are described for the first time. The morphological data will be quite useful for identification and characterization of the chafer, a poorly known species. It will also be an important basis for the chafer control when it breaks out.展开更多
The objective of this work was to evaluate the progress of the areolate mildew of cotton under different soil cover and spacing conditions. The experiment was carried out using randomized blocks and a 2 × 3 facto...The objective of this work was to evaluate the progress of the areolate mildew of cotton under different soil cover and spacing conditions. The experiment was carried out using randomized blocks and a 2 × 3 factorial design, with two spacings (0.45 m and 0.90 m) and three soil covers (no cover, Pennisetum glaucum and Crotalaria spectabilis) with four replications. The plants were inoculated with R. areola, sixty DAS. A total of 14 evaluations of disease severity were performed. At the lower, middle and upper thirds of plants, a diagram scale with nine levels of severity was used and the resulting data were converted into the AUDPC. Gompertz, logistic, and monomolecular mathematical models were tested in the disease severity curves for each third. Agronomics characteristics were evaluated as well. Significant differences of AUDPC were found for the cotton plants thirds, and the middle third was the highest AUDPC. Significant difference for the lower and upper thirds, whose AUDPC were highest on 0.90 m spacing, was observed too. The disease progress curves of the thirds did not fit the tested models. Significant results to the both covers situations, where the treatments grown on crotalária cover and without cover had highest AUDPC, were evidenced. The treatments with C. spectabilis cover were taller than other treatments. Significant data were observed for the cover crops used and in the treatments grown at 0.90 m spacing, to residual cover and crop yield, respectively.展开更多
The female-produced sex pheromone of Den-drolimus superans was identified by gas chromatography (GC), coupled GC-mass spectrometry (GC-MS), electroan-tennographic (EAG) studies and field tests as a blend of (Z,E)-5,7-...The female-produced sex pheromone of Den-drolimus superans was identified by gas chromatography (GC), coupled GC-mass spectrometry (GC-MS), electroan-tennographic (EAG) studies and field tests as a blend of (Z,E)-5,7-dodecadienal (Z5,E7-12:Ald) and (Z,E)-5,7-dodeca-dien-1-ol (Z5,E7-12:OH). In D. kikuchii, (Z,E)-5,7-dodeca-dien-1-yl acetate (Z5,E7-12:OAc) and Z5,E7-12:OH were found by GC and GC-MS analyses. However, in EAG studies male antennae were more sensitive to Z5,E7-12:OAc and (Z,E)-5,7-dodecadien-l-yl propionate (Z5,E7-12:OPr) than Z5,E7-12:OH. For D. spectabilis, Z5,E7-12:OH had been previously reported as the sex pheromone. However, in our studies, traps baited with Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr in a ratio of 1:1:1 caught three times more males than those baited with Z5,E7-12:OH alone. Relatively strong EAG responses were elicited from male antennae by Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr, but in addition to Z5,E7-12:OH, only very small amounts of Z5,E7-12:OAc was found in展开更多
Aims We investigated the treeline dynamics of two environmentally con-trasting areas in the Nepalese Himalaya to address the following questions:(i)Does the timing of establishment of the current tree-line differ betw...Aims We investigated the treeline dynamics of two environmentally con-trasting areas in the Nepalese Himalaya to address the following questions:(i)Does the timing of establishment of the current tree-line differ between the two study areas,and can area-specific tree-line developments be identified?(ii)Do recruitment patterns and height growth indicate recent climate-driven treeline advance,fol-lowing the general prediction for the central Himalayan region,in the two study areas?Methods a dry-climate treeline dominated by Pinus wallichiana and a mesic-climate treeline with Abies spectabilis were selected for study.In each area,we sampled the size and age structure of the study spe-cies along three elevational transects(20-m wide)from the forest line to the tree species line crossing the treeline.We also sampled treeline trees from within and outside transects to reconstruct past treeline establishment dynamics.Important Findings Despite differences in moisture regimes,tree species and recent climate trends,our two study areas showed very similar treeline dynamics over the past six decades.In both areas,the recruitment of treeline trees indicates stationary treelines over the past six decades with the current treelines being dominated by trees that were established around 1990.the mesic area has experienced an overall climatic warming trend,and the stationary Abies treeline is hypothesized to be regulated by non-climatic factors,notably grazing.the dry area has not experienced warming but increased climatic variability and some very cool summers in the recent dec-ades may explain the stationary to weakly receding Pinus treeline,which appears more climatically controlled with decreased recruit-ment over the past decades and decreased growth towards higher elevations.In both areas,there is a potential for treeline advance,depending on future land use and climate change.our results highlight the importance of conducting treeline ecotone analyses for several sites or areas,and considering both climatic and non-climatic drivers of the treeline dynamics within each of these areas,for understanding regional treeline dynamics.展开更多
文摘This study aimed to decipher the mechanism by which exogenous methyl jasmonate(MeJA)regulated the photosynthesis of Malus spectabilis leaves under ozone(O_(3))stress.The photosynthetic parameters and chlorophyll fluorescence parameters of M.spectabilis‘Hongjiu’seedlings under O_(3)stress were measured by spraying different concentrations of MeJA.The results showed that O_(3)stress significantly reduced the chlorophyll a and total chlorophyll content,net photosynthetic rate(Pn),stomatal conductance(G_(s)),transpiration rate(T_(r)),maximum fluorescence yield(F_(m)),maximum quantum yield of photosystem II(F_(v)/F_(m)),and actual photochemical efficiency of photosystem II(Ф_(PSII)),while increasing the intercellular CO_(2)concentration(Ci).Exogenous MeJA reduced the Ci and original fluorescence yield(Fo),while increasing chlorophyll a,chlorophyll b,and total chlorophyll content,P_(n),G_(s),T_(r),F_(m),F_(v)/F_(m),andФ_(PSII) of the leaves under O_(3)stress.The application of 150μmol/L MeJA showed the best effect.The above results demonstrated that exogenous MeJA could enhance chlorophyll content and photosynthetic capacity,thereby improving the tolerance of M.spectabilis to O_(3)stress.
基金supported by the National Key Research and Development Program of China(No.2021YFA0910500)the National Natural Science Foundation of China(No.U22A20380 and 82104043)+1 种基金the Innovative Research Groups of the National Natural Science Foundation of China(No.81721005)the Science and Technology Major Project of Hubei Province(No.2021ACA012).
文摘Spectasterols F−O(1−10),ten interesting ergosterols with an aromatized B ring,were obtained from Aspergillus spectabilis.Their structures and absolute configurations were determined using a combination of high-resolution electrospray ionization mass spectrometry(HR-ESI-MS),nuclear magnetic resonance(NMR)spectroscopy,single-crystal X-ray diffraction analyses,and electronic circular dichroism(ECD)calculations.Structurally,these aromatic ergosterols feature versatile side chains.Notably,compound aromatic ergosterols featured versatile side chains,and compound 4 is an unusual C23 ergosterol characterized by a shorter side chain due to oxidative cleavage between C-23 and C-24.All compounds were evaluated for their neuroprotective activities,with compound 8 showing a dose-dependent ability to reduce apoptosis and protect mitochondrial function in glutamate-induced SH-SY5Y cells.
基金Supported by Natural Science Foundation of Fujian Province(2008J0052 )Technology Program in Xiamen City(3502Z20072007)~~
文摘[Objective] The research aimed to discuss the effects on rooting,physiological and biochemical indicators of Bougainvillea spectabilis cuttings by remaining leaf combining with soaking cuttings in IBA.[Method] Effects of remaining leaf combining with IBA on rooting,physiological and biochemical indicators of B.spectabilis cuttings were studied under the regulation and control of intelligent seed propagation system,and then set four treatments：remaining leaf combining with soaking in clean water,remaining leaf combining with soaking in IBA,defoliation combining soaking in clean water,and defoliation combining with soaking in IBA.[Result] The soluble sugar content was high,but indoleacetic acid oxidase activity was lower in the initial stage of adventitious root differentiation in treatment of remaining leaf.While the rooting number,root length,the root mass growth and survival rate of cutting were obviously higher than that in treatment of defoliation.Compared to the treatment soaking in clean water,the treatment soaking in 500×10^-6 IBA increased the soluble sugar content in leaves of cuttings and enhanced rooting of cuttings.[Conclusion] The survival rate and rooting of cuttings improved obviously in the treatment of remaining leaf combining with soaking in 500×10^-6 IBA before cutting under the regulation and control of intelligent seed propagation system.
文摘A dendroclimatic study was conducted in the treeline ecotone of Barun Valley, eastern Nepal, to determine the tree-ring climate response and ring width trend of Abies spectabilis. A 160-year-old chronology, from 1850 to 2010, was developed from 38 tree-ring samples. No higher growth in recent decades was observed in tree-ring width in this area. The mean temperature of the current year in February and in the combined winter months of December, January, and February showed significant positive correlation with tree-ring width, although no significant correlation was found between tree-ring width and the precipitation pattern of the region. This tree-ring climate response result is different from that in other studies in Nepal, which could be attributed to location and elevation.
基金We thank the Kathmandu Center for Research and Education,CAS-TU,for help during the fieldwork。
文摘The Himalayas are characterized by a broad gradient of bioclimatic zones along their elevation.However,less is known how forest growth responds to climatic change along elevation.In this study,four standard treering width chronologies of Himalayan fir(Abies spectabilis)were developed,spanning 142–649 years along an elevation gradient of 3076–3900 m a.s.l.Principal component analysis classified the four chronologies into two groups;the ones at lower elevations(M1 and M2)and higher elevations(M3 and M4)show two distinct growth trends.Radial growth is limited by summer(June–August)precipitation at M3,and by precipitation during spring(March–May)and summer at M4.It is limited by spring temperatures and winter precipitation(December–February)at M1.Tree-ring width chronologies also significantly correlate with winter and spring Palmer Drought Severity Index(PDSI)at M1,and with summer PDSI at M3 and M4.Thus,Himalayan fir growth at high elevations is mainly limited by moisture stress rather than by low temperatures.Furthermore,the occurrence of missing rings coincides with dry periods,providing additional evidence for moisture limitation of Himalayan fir growth.
文摘Objective:To investigate the effect of two extracts of Bougainvillea spectabilis(B. spectabilis) flowers with yellow and pink/purple on brain oxidative stress and neuronal damage caused in rats by systemic rotenone injection. Methods:Rotenone 1.5 mg/kg was given three times per week alone or in combination with B. spectabilis flowers extracts(25 mg or 50 mg) via the subcutaneous route for 2 weeks. Brain concentrations of the lipid peroxidation marker malondialdehyde(MDA),reduced glutathione,nitric oxide(nitrite),the pro-inflammatory cytokine interleukin-1beta(Il-1β) as well as butyrylcholinesterase,and paraoxonase-1(PON-1) activities,were determined. Histopathology and caspase-3 immunohistochemistry were also performed. Results:Rotenone resulted in significant increases of brain MDA(the product of lipid peroxidation),and nitric oxide content along with decreased brain reduced glutathione. There were also marked and significant inhibition of brain PON-1 and BCh E activities and increased Il-1β in brain of rotenone-treated rats. B. spectabilis flowers extract itself resulted in brain oxidative stress increasing both lipid peroxidation and nitrite content whilst inhibiting PON-1 activity. The yellow flowers extract inhibited BCh E activity and increased brain Il-1β. When given to rotenone-treated rats,B. spectabilis extracts,however,decreased lipid peroxidation while their low administered doses increased brain GSH. Brain nitrite decreased by the pink extract but showed further increase by the yellow extract. Either extract,however,caused further inhibition of PON-1 activity while the yellow extract resulted in further inhibition of BChE activity. Histopathological studies indicated that both extracts protected against brain,liver and kidney damage caused by the toxicant. Conclusions:These data indicate that B. spectabilis flowers extracts exert protective effect against the toxic effects of rotenone on brain,liver and kidney. B. spectabilis flowers extracts decreased brain lipid peroxidation and prevented neuronal death due to rotenone and might thus prove the value in treatment of Parkinson's disease.
文摘The long-legged chafer Hoplia spectabilis Medvedev was described in 1952. Its occurrence was rarely reported and the document about its morphological details was not found. However, the chafer did frequently break out at Buha River valley in Tianjun county, Qinghai province, China since 2005. In this paper, we present a comprehensive description and illustrations of morphological characteristics of H. spectabilis from local collection, including developmental stages of adult, egg, larva and pupa. Among them, characteristics of the larva and pupa, the male genitalia as well as the difference between male and female are described for the first time. The morphological data will be quite useful for identification and characterization of the chafer, a poorly known species. It will also be an important basis for the chafer control when it breaks out.
基金thank the Coordination for the Improvement of Higher Education Personnel(CAPES),for the grant given to the first authorto the Graduate Environment and Agricultural Production Systems Program(PPGAT)and all faculty members for the support and assistance given during the study period.
文摘The objective of this work was to evaluate the progress of the areolate mildew of cotton under different soil cover and spacing conditions. The experiment was carried out using randomized blocks and a 2 × 3 factorial design, with two spacings (0.45 m and 0.90 m) and three soil covers (no cover, Pennisetum glaucum and Crotalaria spectabilis) with four replications. The plants were inoculated with R. areola, sixty DAS. A total of 14 evaluations of disease severity were performed. At the lower, middle and upper thirds of plants, a diagram scale with nine levels of severity was used and the resulting data were converted into the AUDPC. Gompertz, logistic, and monomolecular mathematical models were tested in the disease severity curves for each third. Agronomics characteristics were evaluated as well. Significant differences of AUDPC were found for the cotton plants thirds, and the middle third was the highest AUDPC. Significant difference for the lower and upper thirds, whose AUDPC were highest on 0.90 m spacing, was observed too. The disease progress curves of the thirds did not fit the tested models. Significant results to the both covers situations, where the treatments grown on crotalária cover and without cover had highest AUDPC, were evidenced. The treatments with C. spectabilis cover were taller than other treatments. Significant data were observed for the cover crops used and in the treatments grown at 0.90 m spacing, to residual cover and crop yield, respectively.
基金This work was supported by the National Natural Science Foundation of China (Grant No. 39970141).
文摘The female-produced sex pheromone of Den-drolimus superans was identified by gas chromatography (GC), coupled GC-mass spectrometry (GC-MS), electroan-tennographic (EAG) studies and field tests as a blend of (Z,E)-5,7-dodecadienal (Z5,E7-12:Ald) and (Z,E)-5,7-dodeca-dien-1-ol (Z5,E7-12:OH). In D. kikuchii, (Z,E)-5,7-dodeca-dien-1-yl acetate (Z5,E7-12:OAc) and Z5,E7-12:OH were found by GC and GC-MS analyses. However, in EAG studies male antennae were more sensitive to Z5,E7-12:OAc and (Z,E)-5,7-dodecadien-l-yl propionate (Z5,E7-12:OPr) than Z5,E7-12:OH. For D. spectabilis, Z5,E7-12:OH had been previously reported as the sex pheromone. However, in our studies, traps baited with Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr in a ratio of 1:1:1 caught three times more males than those baited with Z5,E7-12:OH alone. Relatively strong EAG responses were elicited from male antennae by Z5,E7-12:OH, Z5,E7-12:OAc and Z5,E7-12:OPr, but in addition to Z5,E7-12:OH, only very small amounts of Z5,E7-12:OAc was found in
基金Research Council of Norway under the project HimaLines(190153/V10)RCN funds to A.H.under the‘The PPS Arctic project’,Grolle Olsen fund and University fund from Faculty of Mathematics and Natural Science at the University of Bergen supported for the field.
文摘Aims We investigated the treeline dynamics of two environmentally con-trasting areas in the Nepalese Himalaya to address the following questions:(i)Does the timing of establishment of the current tree-line differ between the two study areas,and can area-specific tree-line developments be identified?(ii)Do recruitment patterns and height growth indicate recent climate-driven treeline advance,fol-lowing the general prediction for the central Himalayan region,in the two study areas?Methods a dry-climate treeline dominated by Pinus wallichiana and a mesic-climate treeline with Abies spectabilis were selected for study.In each area,we sampled the size and age structure of the study spe-cies along three elevational transects(20-m wide)from the forest line to the tree species line crossing the treeline.We also sampled treeline trees from within and outside transects to reconstruct past treeline establishment dynamics.Important Findings Despite differences in moisture regimes,tree species and recent climate trends,our two study areas showed very similar treeline dynamics over the past six decades.In both areas,the recruitment of treeline trees indicates stationary treelines over the past six decades with the current treelines being dominated by trees that were established around 1990.the mesic area has experienced an overall climatic warming trend,and the stationary Abies treeline is hypothesized to be regulated by non-climatic factors,notably grazing.the dry area has not experienced warming but increased climatic variability and some very cool summers in the recent dec-ades may explain the stationary to weakly receding Pinus treeline,which appears more climatically controlled with decreased recruit-ment over the past decades and decreased growth towards higher elevations.In both areas,there is a potential for treeline advance,depending on future land use and climate change.our results highlight the importance of conducting treeline ecotone analyses for several sites or areas,and considering both climatic and non-climatic drivers of the treeline dynamics within each of these areas,for understanding regional treeline dynamics.
