Response of needle dark respiration of Pinus koraiensis and Pinus sylvestriformis to elevated CO₂ concentrations for four growing seasons’ exposure     

Zhou YuMei  Han ShiJie  Zhang HaiSen  Xin LiHua  Zheng JunQiang 《中国科学D辑(英文版)》2007,50(4):613-619

The long-term effect of elevated CO2 concentrations on needle dark respiration of two coniferous species-Pinus koraiensis and Pinus sylvestriformis on the Changbai Mountain was investigated using open-top chambers. P. Koraiensis and P. Sylvestriformis were exposed to 700,500μmol·mol-1 CO2 and ambient CO2(approx.350 μmol·mol-1)for four growing seasons. Needle dark respiration was measurd during the second, third and fourth growing seasons' exposure to elevated CO2.The results showed that needle dark respiration rate increased for P. Koraiensis and P. Sylvestriformis grown at elevated CO2 concentrations during the second growing season, could be attributed to the change of carbohydrate and/or nitrogen content of needles. Needle dark respiration of P. Koraiensis was stimulated and that of P. Sylvestriformis was inhibited by elevated CO2 concentrations during the third growing season. Different response of the two tree species to elevated CO2 mainly resulted from the difference in the growth rate. Elevated CO2 concentrations inhibited needle dark respiration of both P. Koraiensis and P. Sylvestriformis during the fourth growing season. There was consistent trend between the short-term effect and the long-term effect of elevated CO2 on needle dark respiration in P. Sylvestriformis during the third growing season by changing measurement CO2 concentrations. However, the short-term effect was different from the long-term effect for P. Koraiensis. Response of dark respiration of P. Koraiensis and P. Sylvestriformis to elevated CO2 concentrations was related to the treatment time of CO2 and the stage of growth and development of plant. The change of dark respiration for the two tree species was determined by the direct effect of CO2 and long-term acclimation. The prediction of the long-term response of needle dark respiration to elevated CO2 concentration based on the short-term response is in dispute.  相似文献   

岷江上游大沟流域油松人工幼林生物量组成及其影响因素   总被引：2，自引：1，他引：2  

李武斌  包维楷  何丙辉  吴文妍  李芳兰 《山地学报》2007,25(2):236-244

为了揭示人工林不同层次的生物量组成关系及其影响因素,选择岷江上游大沟流域的油松人工林,调查分析了林分不同层次生物量组成及其关系,探讨了乔木密度、坡向、海拔对生物量的影响。发现:1)两种林龄油松人工林生物量分配基本一致,即,乔木层>灌木层>草本层;乔木各构件生物量大小顺序为:枝>干>叶>根>果/皮。同时指出,枝叶对下木层生物量的影响显著。2)乔木密度显著控制了林分生物量及其组成,在本调查范围内坡向的影响似乎不明显;海拔对22 a油松影响显著,而24 a的不显著;综合分析表明,本区域内,22 a油松保持在3 800株/hm2左右和24 a在3 500株/hm2左右时,有助于林分生物量的稳定与提高,促进生态系统功能的恢复。  相似文献   

Signals of tree volume and temperature in a high‐resolution record of pollen accumulation rates in northern Finland     

F. Mazier  A. B. Nielsen  A. Broström  S. Sugita  S. Hicks 《第四纪科学杂志》2012,27(6):564-574

Pollen accumulation rates (PARs) provide a potential proxy for quantitative tree volume (m³ ha^?1) reconstruction with reliable absolute pollen productivity estimates (APPEs). We obtained APPEs for pine, spruce and birch at their range limits in northern Finland under two temperature periods (‘warm’ and ‘cold’) based on long‐term pollen trap and tree volume records within a 14‐km radius of each trap. APPEs (mean ± SE; × 10⁸ grains m^?3 a^?1) tend to be higher for the ‘warm’ periods (pine 123.8 ± 24.4, birch 528.0 ± 398.4, spruce 434.3 ± 113.7) compared with the ‘cold’ periods (pine 95.5 ± 37.3, birch 317.3 ± 282.6, spruce 119.6 ± 37.6), although the difference is only significant for spruce. Using an independent temperature record and the APPEs obtained, we reconstruct a low‐frequency record of pine volume changes over the last 1000 years at Palomaa mire, where a high‐resolution record of Pinus PARs is available. Five phases are distinguished in the reconstruction: moderate pine volume, AD 1080–1170; high volume, AD 1170–1340; low volume, AD 1340–1630; very low volume, AD 1630–1810; and rising pine volume, AD 1810–1950. These phases do not coincide with periods of high or low June–July–August temperatures, and thus appear to reflect regional variations in tree volume, while high‐frequency changes within each time‐period block show variations in PARs in response to temperature. Copyright © 2012 John Wiley & Sons, Ltd.  相似文献   

秦巴山区马尾松林和油松林的空间分布及亚热带与暖温带界线划分   总被引：1，自引：4，他引：1  

姚永慧  寇志翔  胡宇凡  张百平 《地理学报》2020,75(11):2298-2306

秦岭不仅是中国南北的地理分界线,也是中国亚热带和暖温带的气候分界线,在中国地理生态格局中占有重要的地位和作用。由于过渡带的复杂性、过渡性和异质性以及划分指标、研究目的的不同,学术界关于这一南北地理—生态分界线的具体位置一直有争论。为了进一步揭示秦巴山区过渡带的特征,明确中国南北地理—生态分界线的位置,本文选择马尾松（Pinus massoniana）林和油松（Pinus tabulaeformis）林这两类分别代表中国南方亚热带针叶林和北方温带针叶林的植被,结合研究区SRTM地形数据、气温和降水数据等,以年降水、最冷月（1月）气温、最热月（7月）气温和年均温为气候指标,详细分析了这两类植被在秦巴山区的空间分布及二者分界线处的气候条件。结果表明：① 马尾松林和油松林的分界线及相应位置的气候指标可以作为亚热带与暖温带界线划分的植被—气候指标之一。秦巴山区亚热带针叶林（马尾松林）与温带针叶林（油松林）的分界线位于伏牛山南坡至汉中盆地北缘一线（秦岭南坡）海拔1000~1200 m处;分界线处气候指标稳定：年降水750~1000 mm,年均温12~14 ℃,最冷月气温0~4 ℃,最热月气温22~26 ℃。② 通过综合的植被—气候指标来划分秦巴山区亚热带和暖温带的界线,能更科学地确定气候带分界线的位置及过渡带的特征,更全面地反映地表植被—气候格局的变化。此外,秦巴山区亚热带与暖温带的界线应该是由亚热带与暖温带针叶林分界线、阔叶林分界线、灌丛分界线等组成的一个过渡带。本文的研究结果为亚热带与暖温带划分指标的选取提供了一定的科学依据。  相似文献   

A laboratorial study on influence of alkaline and oxidative environment on preservation of Pinus tabulaeformis pollen     

Fang Tian  Xianyong Cao  Qinghai Xu  Yuecong Li 《Frontiers of Earth Science》2009,3(2):226-230

Different sedimentary settings can influence preservation of pollens, which would lead to misinterpretation of fossil pollen spectrum. This study investigates the influence on the preservation of Pinus tabulaeformis pollen by simulating alkaline and oxidative environment in the laboratory. There was no obvious change in the content of Pinus tabulaeformis pollen while comparing the original with the ones that were immersed with 10% NaOH liquor for ten days, or boiled for five hours, and or boiled with 20%–30% NaOH for one hour, respectively. However, the pollen fossils were obviously corroded and eroded after being boiled with 40% NaOH for one hour and were seriously corroded after five hours. The result indicates that Pinus tabulaeformis pollen is quite durable in alkaline environment and heating condition within a shorter period of time, although alkaline environment has a disadvantage for its preservation. We also tested the influence of oxidation on Pinus tabulaeformis pollen preservation with KMnO₄ as oxidant. The result presents that the number of remaining Pinus tabulaeformis pollen grains decreased quickly after being dipped in KMnO₄ along with extending the reaction time and reinforcing oxidant. The rate of remnant pollen grains was less than 1% after being dipped with 2% KMnO₄ for one hour. It is suggested that oxidative environment has stronger influence on Pinus tabulaeformis pollen preservation than alkaline environment.  相似文献   

油松年轮记录的河北围场公元1884年以来5～6月平均温度   总被引：3，自引：3，他引：0       下载免费PDF全文

刘禹  田华  宋慧明  梁剑鸣  蔡秋芳  孙军艳 《第四纪研究》2009,29(5):896-904

相关函数分析表明,河北围场的油松年轮宽度指数与 5～6月平均温度显著相关,在此基础上,设计转换方程,重建了该地区1884年至2002年当年5月至6月的平均温度,重建序列的方差解释量达到43.7%(调整自由度后为41.3%)。重建温度序列表明,温度低于多年(1884～2002年)平均温度的时段主要有 1897～1901年、1913～1923年、1949～1978年和 1992～1995年; 高于多年平均温度的时段主要有 1884～1896年、1902～1912年、1924～1942年和 1979～1992年。重建的温度序列具有较大的区域代表性,它与陕西南五台 5～7月温度显著相关,年际尺度上相关系数为r＝0.18(N＝119,p<0.05),它也与由历史文献记录划分的大同北京二地旱涝指数及亚洲太平洋年代际涛动指数(PDO)均显著相关,表明重建序列在一定程度上反映了大范围的气候变化状况。  相似文献   

贺兰山油松生长的气候响应机制初步探讨   总被引：21，自引：9，他引：12       下载免费PDF全文

史江峰  刘禹  E.Vaganov  蔡秋芳  V.Shishov 《第四纪研究》2005,25(2):245-251

应用VaganovShashkin模型对贺兰山油松的生长变化作了拟合,发现4～8月的降水量大小决定了该年树木生长的宽度变化,另外,除5月外的1～8月份温度和树木生长的负相关是因为较高的温度不利于土壤中水分的保持,间接地导致树木生长的减慢。VS模型在贺兰山地区取得了良好的拟合效果,更为符合树木生长的生理学意义。通过拟合序列和3个采样点树轮宽度序列的对比发现,拟合序列代表着一个较大范围树轮宽窄的变化。坡向对树木生长的影响较大,甚至超过了海拔高度和距离的影响,故建议树木年轮气候学采样应沿着同一坡向采样。  相似文献   

Climate response and radial growth of Pinus tabulaeformis at different altitudes in Qilian Mountains     

Liang Jiao  ChangLiang Qi  RuHong Xue  Ke Chen  XiaoPing Liu 《寒旱区科学》2021,13(6):496-509

In order to test whether the relationship between climate and the radial growth of trees is affected by altitude, altitude variability and time stability of climate-influenced radial growth of a dominant conifer, Chinese pine (Pinus tabulaeformis), in the eastern Qilian Mountains were studied against the background of climate change using dendrochronology. Results show that 1) droughts at the end of the growing season of last year and during the early and middle growing season of the current year were the main limiting factors for the radial growth of Chinese pine at two altitude gradients; this was determined by analyzing the relationship between tree-ring width chronologies and climate factors. 2) The sensitivity of the radial growth of trees to climate change gradually decreased and was affected more by drought stress at a lower altitude. 3) An unstable divergence response was observed in the radial growth at the two altitudes, in response to controlling climatic factors; this observation was based on the moving correlation analysis of growth/climate relationships, and the aggravation of drought stress caused by increasing temperature was the main reason. 4) The growth rate of Chinese pine at the two altitudes increased at first and then decreased, as measured by basal area increment (BAI) modeling. Future temperature rises may have significant effects on mountain forest ecosystems in arid and semi-arid regions. Effective management and protection measures should be taken, according to the response patterns of trees to climate change at different altitude gradients.  相似文献   

干旱荒漠地区沙地樟子松育苗试验研究   总被引：5，自引：2，他引：3  

荔克让  孙宏义  张华 《中国沙漠》2000,20(1):98-101

春季低温低湿、大风频繁,夏季干旱高温,土壤颗粒粗,持水力低是干旱荒漠地区沙地樟子松育苗的主要制约性因素。只要抓好土壤改良、春季苗床覆盖、灌水、遮荫、越冬覆盖和施肥施药等措施,即可保证沙地樟子松育苗的成功。  相似文献   

Crown fuel characteristics and carbon emission from Japanese red pine stands burned by crown fire in Mt. Palgong, South Korea     

Byungdoo LEE  Myoung Soo WON  Yohan LEE  Myung Bo LEE 《山地科学学报》2012,9(5):656-664

Carbon emissions from forest fires are considered an important factor of ecosystem carbon balance and global climate change. Carbon emissions from Japanese red pine stands (Pinus densiflora S. et Z.) burned by crown fire were estimated at Mt. Palgong in Daegu Metropolitan City, and crown fuel characteristics, including crown bulk density, crown base height, and fuel moisture content of Japanese red pine, were analyzed. Total biomass combusted was calculated by subtracting the biomass of burned stands from that of unburned stands exhibiting similar stand structures and site environments. Ten trees in the unburned area and five trees in the burned area were cut by using direct harvesting techniques to estimate crown layer biomass. All biomass sampled was oven-dried and weighed. The dry weight ratios of stems, branches, and needles were 70%, 21%, and 9%, respectively. The available fuel load susceptible to combustion during the crown fire spread was equivalent to 55% of the crown layer biomass. The crown bulk density was 0.24 kg/ m 3 on average. The estimated amount of CO 2 was 23,454 kg CO 2 /ha for the crown layer. These results will be useful for calculating the amount of CO 2 emitted from forest fires and for developing a forest carbon model in P. densiflora forests.  相似文献