Dendroclimatic methods were used to investigate the fundamental relationships between the temperature variables and the growth of climatically relic Picea meyeri Rehd. et Wils. on sandy land of Inner Mongolian gra...Dendroclimatic methods were used to investigate the fundamental relationships between the temperature variables and the growth of climatically relic Picea meyeri Rehd. et Wils. on sandy land of Inner Mongolian grasslands in the Xilin River Basin. The annual mean temperature and accumulated temperature (above 5 ℃, 10 ℃) respectively showed no significant correlation with the spruce growth relative to summer mean temperature, which displayed strong coherence with tree growth ( P <0.01). The mean temperature in May showed significantly negative correlation with spruce growth ( P <0.05). Furthermore, it was revealed that the negative influence of May temperature was due to monthly mean maximum temperature ( T max ) ( P <0.01) other than monthly mean minimum temperature ( T min ) values ( P <0.1), which indicated that the use of T min and T max separately can allow much more insights on the temperate influence. In addition, extreme maximum temperature in May and June might impose the most detrimental influence on tree growth in semi_arid Inner Mongolian grassland. The analysis of the recorded meteorological data demonstrated that the increases in temperature were synchronous with slight decreases in precipitation in the growing season, which suggested that P. meyeri may reduce growth due to temperature_induced drought. On the other hand, the analysis for decadal periods explored that trees appeared to reduce the sensitivity to the warming, and consequently increased sensitivity to rainfall. This may serve as a baseline for more accurate predictions of the potential impacts of altered climate regimes on tree growth.展开更多
The annual growth rings of ten trees and the soils near the tree roots were sampled from the mining area of lead-and zinc-dominant metals in the Xixia Mountain, Nanjing, for the determination of chemical element conte...The annual growth rings of ten trees and the soils near the tree roots were sampled from the mining area of lead-and zinc-dominant metals in the Xixia Mountain, Nanjing, for the determination of chemical element contents. The study results showed that the elemental contents in the tree rings were correlated with those in the soils, i. e., the elemental contents in the tree rings increased with those in the soils, even in the cases of different environments and different tree species. Therefore, a time-concentration sequence could be set up on the basis of determining the elemental contents in the successive annual growth rings of trees to qualitatively reflect the annual variations of relevant elements in the soils, and a time-concentration sequence of elemental contents in soils could also be established in terms of related model to reproduce the dynamic changes of the surroundings.展开更多
The chemical element contents in tree rings are correlated with those in the soils near the tree roots. Theresults in the present study showed that the correlation between them could be described using the followinglo...The chemical element contents in tree rings are correlated with those in the soils near the tree roots. Theresults in the present study showed that the correlation between them could be described using the followinglogarithmic linear correlation model:lgC'(Z) = α(Z) + b(Z)lgC(Z).Therefore, by determining the chrono-sequence C(Z, t), where Z is the atomic number and t the year ofelemental contents in the annual growth rings of trees, we could get the chrono-sequence C'(Z, t) of elementalcontents in the soil, thus inferring the dynamic variations of relevant elemental contents in the soil.展开更多
文摘Dendroclimatic methods were used to investigate the fundamental relationships between the temperature variables and the growth of climatically relic Picea meyeri Rehd. et Wils. on sandy land of Inner Mongolian grasslands in the Xilin River Basin. The annual mean temperature and accumulated temperature (above 5 ℃, 10 ℃) respectively showed no significant correlation with the spruce growth relative to summer mean temperature, which displayed strong coherence with tree growth ( P <0.01). The mean temperature in May showed significantly negative correlation with spruce growth ( P <0.05). Furthermore, it was revealed that the negative influence of May temperature was due to monthly mean maximum temperature ( T max ) ( P <0.01) other than monthly mean minimum temperature ( T min ) values ( P <0.1), which indicated that the use of T min and T max separately can allow much more insights on the temperate influence. In addition, extreme maximum temperature in May and June might impose the most detrimental influence on tree growth in semi_arid Inner Mongolian grassland. The analysis of the recorded meteorological data demonstrated that the increases in temperature were synchronous with slight decreases in precipitation in the growing season, which suggested that P. meyeri may reduce growth due to temperature_induced drought. On the other hand, the analysis for decadal periods explored that trees appeared to reduce the sensitivity to the warming, and consequently increased sensitivity to rainfall. This may serve as a baseline for more accurate predictions of the potential impacts of altered climate regimes on tree growth.
基金Project supported by the National Natural Science Foundation of China.
文摘The annual growth rings of ten trees and the soils near the tree roots were sampled from the mining area of lead-and zinc-dominant metals in the Xixia Mountain, Nanjing, for the determination of chemical element contents. The study results showed that the elemental contents in the tree rings were correlated with those in the soils, i. e., the elemental contents in the tree rings increased with those in the soils, even in the cases of different environments and different tree species. Therefore, a time-concentration sequence could be set up on the basis of determining the elemental contents in the successive annual growth rings of trees to qualitatively reflect the annual variations of relevant elements in the soils, and a time-concentration sequence of elemental contents in soils could also be established in terms of related model to reproduce the dynamic changes of the surroundings.
文摘The chemical element contents in tree rings are correlated with those in the soils near the tree roots. Theresults in the present study showed that the correlation between them could be described using the followinglogarithmic linear correlation model:lgC'(Z) = α(Z) + b(Z)lgC(Z).Therefore, by determining the chrono-sequence C(Z, t), where Z is the atomic number and t the year ofelemental contents in the annual growth rings of trees, we could get the chrono-sequence C'(Z, t) of elementalcontents in the soil, thus inferring the dynamic variations of relevant elemental contents in the soil.
