不同种源花楸树幼苗越夏能力的比较

以来自6个种源花楸树1年生幼苗为材料,通过观测苗木田间生长表现、叶片相对电导率、光合特性等生理指标并利用隶属函数综合评价不同种源花楸树对夏季高温环境的适应性,为早期筛选出适应低海拔地区的优良种源奠定理论基础。结果表明:不同种源对高温的适应性表现不同。山东崂山种源的苗高年增长量最大,为34.99 cm,而河北雾灵山种源的地径年增长量最大(6.90 mm);河北驼粱山种源的净光合速率和蒸腾速率最高,分别为12.1μmol CO2·m-2·s-1和6.28μmol H2O·m-2·s-1,而山西庞泉沟种源净光合速率和蒸腾速率最低,分别为8.03μmol CO2·m-2·s-1和4.39μmol H2O·m-2·s-1。山西庞泉沟种源叶片受伤害程度最大,叶伤害指数为46.53%;受伤害最小的是山东泰山种源,叶伤害指数为17.75%。综合评价表明,越夏能力最强的是山东泰山和山东崂山种源,河北种源次之,山西种源最差。     

不同菊花品种根系、地上部和叶片相关指标分析及抗逆性评价

采用盆栽法对6个菊花(Chrysanthemum morifolium Ramat.)品种幼苗的根系和地上部相关指标及叶片光合和气体交换参数进行了比较和相关性分析;并基于叶片相对含水量、相对电导率、丙二醛含量和可溶性糖含量4个生理生化指标,采用隶属函数法对不同菊花品种幼苗的抗旱性和耐热性进行了评价.结果表明:不同菊花品种间幼苗的根系和地上部相关指标及叶片光合和气体交换参数存在一定差异.相关性分析结果表明:根系的大多数相关指标与株高呈显著(P<0.05)或极显著(P<0.01)正相关,但与茎粗和单株叶数却没有显著相关性;并且,单株的根体积、根鲜质量和干质量与单株地上部鲜质量呈极显著正相关(相关系数分别为0.598、0.642和0.599),与单株地上部干质量呈极显著或显著正相关(相关系数分别为0.736、0.606和0.553).主根长与净光合速率和蒸腾速率,平均根长与水分利用效率及单株根鲜质量与蒸腾速率呈显著正相关(相关系数分别为0.475、0.517、0.570和0.477);单株根干质量与蒸腾速率及根系活力与净光合速率和水分利用效率呈极显著正相关(相关系数分别为0.641、0.877和0.814).抗逆性评价结果表明:品种'南农红霞'('Nannong Hongxia')、'大白托桂'('Qx073')和'天使'('Angelina')的平均隶属函数值分别为0.93、0.93和0.72,据此判断这3个菊花品种的抗旱性最强;品种'馒头菊'('Cayman')和'南农红霞'的平均隶属函数值分别为0.82和0.70,据此判断这2个菊花品种的耐热性最强.综上所述,不同菊花品种幼苗的根系相关指标差异明显,并且根系生长状况能够影响地上部的生长和发育,品种'南农红霞'的抗旱性和耐热性均很强,具有较高的抗性育种价值.     

植物生长调节剂对西南桦苗木生长的影响

用 ABT6 和 GA3对西南桦苗木进行叶面喷施试验。试验结果表明 ,GA3的 3种浓度即 2 0× 10 - 6 m g/L、50× 10 - 6 m g/L、80× 10 - 6 m g/L在苗木高生长、地径大小、苗木干鲜重及苗木根系生长发育方面都比清水对照( CK)有明显地提高。ABT6 各浓度特别是 50× 10 - 6 m g/L处理的在苗木分枝数、单株叶面积、苗木干鲜重及苗木根系生长发育方面也比对照有显著的提高。综合各指标 ,用 A BT6 生长调节剂的 50× 10 - 6 mg/L比 2 0× 10 - 6mg/L、80× 10 - 6 mg/L处理及 GA3生长调节剂各浓度处理在生产实践上更适宜用于培育西南桦苗木。     

高温干旱季节遮阳网覆盖对茶园温湿度和茶树生理的影响

研究了高温干旱季节采用遮阳网覆盖红壤丘陵茶园的生态作用和对茶树生理的影响。与露地对照茶园相比,遮阳网覆盖处理茶园在高温干旱季节,各个观测时段的气温、树冠温度、叶面温度、地面温度和土壤温度均明显降低,茶园土壤水分含量、空气湿度和茶叶含水量明显提高,茶叶新梢的叶绿素、咖啡碱和氨基酸含量大幅度提高,茶多酚含量降低11．6％。连续高温干旱27～29d后遮阳网覆盖下茶树的叶片气孔导度、蒸腾速率和净光合速率均明显高于露地对照茶园。     

拟单性木兰不同季节断根和剪枝后蒸腾和光合特性的变化

在2005年春季、夏季和秋季,对10a生拟单性木兰(Parakmeriaomeiensis)进行断根和剪枝处理,模拟移栽,用LICOR-6400测定了植株叶片的蒸腾速率、光合速率等生理指标,探讨这些生理指标对不同季节移栽成活率的影响。结果表明,春季处理后叶片能迅速关闭部分气孔,蒸腾速率和光合速率都减小,两者最低时约为对照的60%,生理机能的减弱有利于维持地上、地下部分的平衡,因而最有利于植株成活。夏季处理后叶片气孔导度显著增加,光合速率和蒸腾速率也随之增大,最高时约为对照的2倍左右,此时,若主要依靠剪枝来降低水分消耗,很难保证水分代谢平衡,移栽成活率低。秋季处理后植株叶片气孔导度高于对照,光合速率和蒸腾速率也增加,但增加幅度相对夏季较小,前期最高约增加40%,此时移栽可以通过适当的剪枝和增加土壤水分含量等措施提高成活率。可见,与水分相关的生理机能的调节机制,决定了移栽后的成活水平,即处理后能迅速调节自身生理机能、减少水分消耗的植株,成活率就高,反之就低。     

高温胁迫对~(14)C-水杨酸在葡萄苗中运转分配的影响

用 38℃高温和 2 7℃正常温度分别处理14 C SA标记的葡萄幼苗叶片 1,3,6 ,12h ,发现常温下14 C SA向外运转的很少 ,而高温下向外运转的更少。高温处理和常温对照的14 C SA都既向上运输又向下运输 ,以向下运输为主 ,但无论向上运输还是向下运输 ,高温下要比常温下运输的少一些。在常温下 1,3,6h ,14 C SA以根系分配的最多 ,12h以茎中分配最多 ,而在高温处理下 1,3h以根中分配最多 ,6 ,12h则以茎中分配最多。高温处理和常温对照下都是离引入叶越近的茎段和叶片 (除引入叶 ) ,14 C SA含量越高     

水淹和恢复对凤丹光合特性和根系活力的影响

选用3年生油用牡丹凤丹(Paeonia ostii)实生苗为试验材料,以常规供水管理的凤丹苗为对照,测定凤丹光合特性以及根系活力和形态随着水淹和水淹恢复处理时间的变化,探究牡丹的耐湿机制。结果表明:(1)水淹后,凤丹叶片净光合速率、蒸腾速率、气孔导度及根系活力均较对照组显著下降,且下降幅度随着水淹时间的延长而增大;在持续水淹过程中,叶片胞间CO_2浓度则呈先下降后上升的变化趋势;水淹168h时,根系活力在所测定指标中下降幅度最大,仅为对照组的2.34%,此时根系变黑且腐烂,大部分根系脱落。(2)凤丹叶片净光合效率的下降在水淹120h过程中与气孔限制性调节密切相关,而到水淹168h时非气孔限制性成为光合作用的限制因子。(3)水淹72h后进行恢复处理120h后,叶片净光合速率、蒸腾速率、胞间CO_2浓度和根系活力均显著上升;恢复处理168h后,净光合速率和胞间CO_2浓度恢复到正常的生长水平,同时绝大部分根尖呈现白色且发育良好,根系生长向正常的生命状态恢复。研究表明,油用牡丹凤丹对水淹胁迫的应答迅速且灵敏,虽不耐水淹,但恢复能力强,这为其栽培管理以及在相对湿润地区推广种植提供了理论依据。     

水肥异区交替灌溉对夏玉米生理指标的影响

以夏玉米品种‘户单4号'为材料,通过防雨棚内微区试验研究了两种灌水量(450 m~3/hm~2和900 m~3/hm~2)条件下水肥异区交替灌溉和均匀灌溉对夏玉米生长以及某些生理指标的影响.结果显示:(1)在节水50%的条件下,水肥异区交替灌溉与高灌水量均匀灌溉的夏玉米生物量、产量均无显著差异.(2)低灌水量时,水肥异区交替灌溉下的玉米根系伤流液、叶片可溶性蛋白含量、硝酸还原酶活性、光合速率、蒸腾速率等均高于均匀灌溉施肥处理,而植株全氮含量及叶片水分利用效率与均匀灌溉施肥的差异不显著.(3)高灌水量时,水肥异区交替灌溉处理除根系活力、光合速率以及蒸腾速率高于均匀灌溉处理外,其他指标均低于后者.研究表明,在低灌水量条件下,水肥异区交替灌溉能使夏玉米保持较高的根系活力和正常生理代谢,提高其叶片水分利用效率,从而达到了节水增产的目的.     

淹涝胁迫对水稻生育后期的生理特性和产量性状的影响

比较研究了水稻（湘中灿３号）在生育后期（孕穗期和乳熟期）进行没顶淹水胁拓处理后几个相关的生理指标和生长发育、产量的形态指标。研究结果显示水稻受淹后完全伸展叶片净光合速率降低,叶绿素含量在孕穗期明显降低,但在乳熟期只有少量下降。电导率明显增加,细胞膜透性增大,脯氨酸含量增加。奶系伤流量和,根系活力降低经与中群伤流液中的主要基酸如Ａｌａ,ＯＰｒｏ,Ｐｈｅ的含量增加,根系伤流量减少,根系活力降低,伤流液     

水分和磷素对木荷不同种源苗木生长和磷效率的影响

以用木荷中心产区的浙江龙泉、福建建瓯、尤溪和江西吉安4个代表性优良种源为试验材料,以广西产红荷为对照,设置不同水分处理和磷素水平的盆栽试验,研究水分和磷素对木荷种源苗木生长和生理指标的影响.结果表明：在不同的水分和磷素处理下,4个参试种源的苗木生长、根系形态参数和磷素吸收效率等均存在显著的遗传差异,福建建瓯和浙江龙泉种源苗木生长量大、根系发达、磷素吸收效率高,生长表现明显优于福建尤溪和江西吉安种源,而广西产红荷则保持其原产地速生、抗旱、耐瘠的特性.土壤水分和磷素对木荷种源苗木生长影响显著.适宜水分条件下,种源苗木径生长、干物质量、根系参数和磷素吸收效率较干旱胁迫条件下高18.5%～105.6%,高磷水平下种源苗木上述性状较低磷处理高37.5%～286.2%.但在干旱和低磷胁迫下,木荷将光合产物更多地分配至地下根系,磷素利用效率也较高,这可能是木荷适应干旱和低磷胁迫的重要生理机制.相对于显著的种源、水分和磷素主效应,其间的交互作用则可以忽略.     

东北南部蒙古栎径向生长对气候变化的响应——以千山为例

蒙古栎是东北森林中最重要的阔叶树种之一.本研究利用树木年代学方法研究中国东北南部千山地区蒙古栎的径向变化,结合1951—2010年的温度和降水等气象数据,利用相关函数分析了树木生长与气候变化的关系,揭示蒙古栎径向生长对气候响应规律.结果表明：研究区4—7月的降水量与蒙古栎年轮宽度呈显著正相关,是限制该地区蒙古栎径向生长的主要限制因子;5月极端最高温度与蒙古栎年轮宽度呈显著负相关,也是影响蒙古栎生长的关键因素.研究期间,蒙古栎年轮宽度与4月降水量的相关显著且稳定,自20世纪80年代开始蒙古栎径向生长对夏季温度的响应敏感性逐渐减弱,对温度的响应表现出从响应夏季温度向响应春季温度的转变.     

川西米亚罗林区主要树木生长对气候响应的差异

为分析青藏高原东缘半湿润区不同树种树木生长对气候变化的响应规律,于川西米亚罗林区海拔3000 m左右(低海拔)采集铁杉、岷江冷杉、紫果云杉,海拔4000 m左右林线位置(高海拔)采集岷江冷杉、四川红杉,共计182棵树木年轮样芯,建立了不同树种的树轮宽度年表,对不同树种的年轮指数与各月气候因子进行相关分析.结果表明： 在低海拔处,树木生长与4、5月气温呈负相关,与4、5月降雨呈正相关,受到春季干旱胁迫的影响;但树种之间存在显著差异： 铁杉的生长受春季干旱胁迫影响最严重,岷江冷杉次之,紫果云杉所受影响很小.在高海拔处,树木生长主要受生长季温度的影响,岷江冷杉年轮指数与当年2、7月最低气温呈显著正相关,与上一年10月最高气温亦呈正相关;四川红杉年轮指数与5月最高气温呈显著正相关,但与2月均温、3月最低气温呈显著负相关.近几十年青藏高原东北缘气候有干暖化趋势,如果这种趋势持续发生,低海拔紫果云杉长势将超过铁杉和岷江冷杉;高海拔处的升温更有利于岷江冷杉的生长.     

Variability of climate–growth relationships along an elevation gradient in the Changbai Mountain, northeastern China

In order to explore climate–growth relationships at different elevations, tree-ring width chronologies of larch (Larix olgensis) were developed from three sampling sites on the northern slope of the Changbai Mountain, northeastern China. There were no consistent trends in statistical characteristics of the tree-ring chronologies along the elevation gradient, since trees in the forest interior had a complacent growth pattern. Monthly mean temperature and monthly total precipitation were used for the analysis. Correlation analysis indicated that temperatures in winter had negative correlations with tree growth (previous November, December and current March for the low-, mid- and high-elevation sites, respectively). The correlations between tree growth and June temperature varied from weakly negative at low elevations to significantly positive at high elevations. Precipitation in June of the growth year had negative relationship with the high-elevation chronology. However, high precipitation was associated with low temperature in early growing season, further supporting that temperature is a growth-limiting factor at high elevations. Our results suggest that along the elevation gradient, L. olgensis may respond in different ways to local climate change.     

帽儿山地区兴安落叶松人工林树木年轮气候学研究

通过帽儿山兴安落叶松（Larix gmelinii）人工林树木年轮样本和气象资料,对该地区兴安落叶松进行了树木年轮气候学研究,结果表明：过去50年年均温度上升达到了显著水平（p<0.05）,平均温度每10年约上升0.4℃,年平均最高气温每10年约上升0.3℃,年平均最低气温每10年约上升0.5℃,但是年降水量随着年份变化不显著（p>0.05）。从月均温度来看,所有月份均出现明显上升趋势,其中冬季2月份温度上升最为明显,达到0.9~1℃/10年,而夏季（6~8月）上升的较小,达到0.2~0.7℃/10年;多数月份降雨量随年龄变化不显著（p>0.05）。在这一气候变暖过程中,早材及总年轮宽度生长随着夏季（6~7月）温度上升而下降,春季(5月)温度的升高而升高,晚材随着秋季（9月）温度上升而增加,导致在年水平上,年轮生长随着年均温的变化不显著（p>0.05）。降雨量在未来气候变化过程中,没有稳定的变化趋势,但是对年轮影响明显,在年水平上,早材与年轮的生长均受降水量的影响较大(p<0.05)。如果未来东北地区气候变暖趋势明显,而降水量变化不明显,春季和秋季温度升高导致的年轮生长增加会被夏季过高温度抑制年轮生长所抵消,因此,落叶松林径向生长受到的影响可能不大。     

中国东南高海拔黄山松生长对气候的响应——以浙江省九龙山和安徽省牯牛降为例

利用中国浙江省西南部九龙山自然保护区和安徽省南部牯牛降的高海拔黄山松树轮径向宽度资料,分别建立了2个树轮宽度差值年表(RES).由子样本信号强度(SSS)>0.8判定,九龙山年表(JLS01)的可靠时段为1884—2010年,牯牛降年表(GNJ01)的可靠时段为1837—2008年.将采样点周围气象站气象数据做算术平均代表区域气候状况,利用相关函数检验了两年表与区域气象数据的月降水量、月平均温度、月平均相对湿度、月总云量和月日照时数的关系.结果表明： 2个高海拔点树木径向生长主要受夏季(上年6、7月,当年6月)水热条件的影响.九龙山年表与上年6、7月温度呈显著正相关,与上年6、7月和当年6月降水及相对湿度呈显著负相关,与上年7月总云量呈显著负相关,与上年6、7月日照时数呈显著正相关;牯牛降年表与上年7月温度呈显著正相关,与上年7月和当年6月降水及相对湿度呈显著负相关,与上年6月总云量呈显著负相关,与上年7月、当年6月日照时数呈显著正相关.由于高海拔地区温度较低,夏季温度的升高有利于该地区树木生长,同时较多降水对应的高相对湿度、高云量和低日照时数,限制了光合作用产物的合成,导致树木的径向生长受到抑制.
     

川西卧龙国家级自然保护区树木生长对气候响应的时间稳定性评估

根据川西卧龙地区岷江冷杉(Abies faxoniana)的年轮宽度资料, 分析了该地区树木生长特征及对气候响应在最近53年(1956-2008年)的异质性特征。结果表明, 在1956-1976年时段, 树木生长速率较快, 晚冬至早春(1月到4月)温度对树木生长有着明显的促进作用, 而春末5月份的高温对于树木生长有限制性影响, 而与日照时数关系不大; 在1977-2008年时段, 树轮生长主要受冬季(11月到1月)低温的限制, 另外, 日照时数对于树木生长的限制性影响明显增强。秋季到早冬(9-12月)降水在两个时段上对树木生长均有一定的限制性影响。树轮指数在1956-1976年时段与温度序列吻合较好, 而在1977-2008年时段树轮指数明显偏低, 与温度序列出现了明显的分离。1977-2008年时段内云层覆盖量增加导致太阳辐射量显著下降, 进而树木可利用的光合有效辐射也相应地降低, 这可能是树木生长速率在此时期明显较慢的主要原因。     

Rapid warming induces the contrasting growth of Yezo spruce (Picea jezoensis var. microsperma) at two elevation gradient sites of northeast China

Accurately assessing the impact of climate changes on tree growth or forest productivity is vital to better understand global carbon cycles. Here, we carried out dendroclimatological research on Yezo spruce (Picea jezoensis var. microsperma) along an elevation gradient in two sites to investigate the effect of rapid warming on spruce growth in northeast China. Results indicated that trees at two low-elevation sites had significantly wider ring widths and higher basal area increment (BAI) compared with high-elevation sites. Ring widths and BAI of Yezo spruce at low elevations showed a clear growth increase during the 1940s–1970s followed by a significant decline after 1980. However, trees at high elevations showed a relatively stable growth during the 1940s–1970s followed by a significant increase after 1980. Rapid warming after 1980 increased the radial growth of Yezo spruce at high-elevation sites, but reduced tree growth at low-elevation sites. Winter precipitation and growing season temperature were positively correlated with radial growth of Yezo spruce at high elevations, but negatively correlated with tree growth at low elevations. A clear pattern of growth and growth-climate relationship changed in 1980. The temperature threshold for determining the impact of climate on Yezo spruce could change with latitude or site. Difference in drought caused by warming may be the main reason for the opposite response of tree growing at different altitudes in northeast China. The mechanism of rapid warming driving contrasting growth at different elevations should also be investigated in other tree species in NE Asia. In the context of future climate warming, our findings are of great significance for tree growth in assessing forest dynamics and carbon cycling.     

Growth decline of Pinus Massoniana in response to warming induced drought and increasing intrinsic water use efficiency in humid subtropical China

Pinus Massoniana is the most widely distributed coniferous species in southern China and one of the most distributed species for plantation in China. It is not uncertain about the responses of tree growth to the combined effects of regional drying and the increase in the intrinsic water-use efficiency (iWUE) due to increased atmospheric CO₂. This study addressed this issue by comparing the tree growth patterns as represented by three tree-ring width chronologies with climate variables and three iWUE series derived from three tree-ring stable carbon isotope discrimination chronologies (Δ¹³C) from Pinus Massoniana in Daiyun Mountain, central Fujian province of China. Among these chronologies, we reported the first tree-ring carbon isotope discrimination chronologies (Δ¹³C) from Fuzhou area spanning last 210 years. It was found that tree radial growth is mainly limited by dry condition from May to October. Growth limitation by cold condition was only found in one high altitude site (780m) in early spring and late autumn. The tree-ring carbon discrimination was enhanced under conditions with low relative humidity and sufficient sunshine in late summer and autumn. In general, the iWUE showed a significantly increasing trend since the 1850s for all the sites in response to the increase in atmospheric CO₂. However, the growth promotion of the increased iWUE on tree growth could not compensate the growth limitation caused by drought. Especially since the 1960s, a growth decline was found at two drought stressed sites at low altitudes. On the other hand, the increase in temperature of spring and autumn and iWUE has most likely enhanced tree growth at the high altitude site.     

不同海拔温度和降水对新疆阿尔泰山西伯利亚落叶松径向生长的影响

为定量并分离关键气候因子对新疆阿尔泰山不同海拔树木径向生长的影响,通过对高、中和低海拔的西伯利亚落叶松(Larixsibirica)树轮宽度标准年表与气候因子分别进行相关、多元线性回归等统计分析,并进一步计算了线性模型中不同气候因素的绝对和相对贡献率。结果表明,高海拔地区,当年6月温度和上年7月降水分别与径向生长呈显著正相关和负相关,两者共同解释西伯利亚落叶松径向生长变异的33.1%,相对贡献率分别为66.2%和33.8%;中海拔地区,当年6月温度和上年6月降水分别与径向生长呈显著正相关和负相关,两者共同解释径向生长变异的26.8%,相对贡献率分别为40.1%和59.9%;低海拔地区,上年6月温度和7月降水分别与径向生长呈显著负相关和正相关,两者共同解释径向生长变异的29.4%,相对贡献率分别为31.9%和68.1%。这表明限制树木径向生长的主要影响因子随海拔的不同而异,在高海拔地区,温度是主要限制因子;而在低海拔地区,降雨是主要限制因子。     

Climate–growth analysis of Qilian juniper across an altitudinal gradient in the central Qilian Mountains, northwest China

In the context of global warming, it is of high importance to assess the influence of climatic change and geographic factors on the radial growth of high-elevation trees. Using tree-ring data collected from four stands of Qilian juniper (Juniperus przewalskii Kom.) across an altitudinal gradient in the central Qilian Mountains, northwest China, we compared the radial growth characteristics and climate–growth relationships at different elevations. Results indicated that there was little difference in the tree-ring parameters of the four chronologies. Correlation analyses both for unfiltered and 10-year high-passed data of monthly climatic variables and chronologies were presented to investigate the climatic forcing on tree growth, and results revealed that the correlation patterns were consistent among the four sites, especially for high-passed data. We employed the principal components analysis method to obtain the first principal component (PC1) of the four chronologies and computed the correlations between PC1 and climate factors. The PC1 correlated significantly with winter (November–January) temperature, prior August and current May temperature, and precipitation in the previous September and current January and April, indicating that tree growth in this region was mainly limited by cold winter temperature and drought in early growing season and prior growing season (prior August and September). However, the climate–growth relationships were unstable; with an increase in temperature, the sensitivity of tree growth to temperature had decreased over the past few decades. Considering the instability of the climate–growth relationships, climate reconstructions based on tree rings in the study area should be approached with more caution.