树木年内径向生长对干旱事件的响应——以贺兰山油松为例

在贺兰山苏峪口国家森林公园,利用径向生长测量仪监测2017和2018年2个生长季内、2个海拔(2010和2330 m)油松的径向生长,研究树木径向生长对干旱的响应。结果表明: 2018年6月的干旱事件使得油松径向生长速率减慢,生长量减小;而7—8月的降水使油松的径向生长重新激活。2018年油松的径向生长主要发生在6—8月,相比2017年延长一个月。油松径向生长与气候因子的响应关系在不同海拔间没有明显的差异。生长季早期干旱对树木径向生长有抑制作用,生长季中后期降水对树木径向生长具有促进作用。该区的气候重建工作中应当充分考虑8月的气候要素对树轮宽度的影响。     

闽西北引种湿加松12年生个体与林分生长适应性

对福建西北地区栽培的湿加松Pinus elliottii × P. caribaea 12年生林分树高与胸径生长分布进行统计分析。结果表明,林分树高分布在3～14 m范围内,胸径生长分布于2～22 cm,林分的经济生长性状呈正态分布。在同等立地条件下,湿加松早期树高生长优于乡土树种马尾松,但马尾松胸径生长6年后有更好的生长量,12年生后胸径生长相接近,马尾松12年生林分中平均木单株材积优于湿加松林分,不过11年生后开始减缓,而湿加松保持持续生长势头。由材积生长来看,各树种个体材积生长正处于快速生长期,湿加松材积生长表现出较强的生长趋势。     

用太阳黑子和自相关因子预测杉木生长

以太阳黑子和自相关因子为预测因子,采用逐步回归分析方法,建立杉木〔Ｃｕｎｎｉｎｇｈａｍｉａｌａｎｃｅｏｌａｔａ（Ｌａｍｂ．）Ｈｏｏｋ．〕胸径生长的预测模型,结果表明前３年和８年的太阳黑子相对数及前５年杉木胸径生长的年轮指数值对杉木胸径生长存在正相关,前１年和４年的太阳黑子相对数及前６年和７年杉木胸径生长的年轮指数值对杉木胸径生长存在负相关,该模型的模拟精度和预测精度分别为９８９５％和９８４５％,且可提前５年进行预测,为林木生长预测提供了新的系统分析方法     

杉木不同生长类型对养分供应的持续效应

应用“正态分布标准差分类法”把杉木(Cunninghamia lanceolata)试验林分树高生长划分为5个生长类型，按不同生长类型进行施肥试验。结果表明，不同生长类型杉木施肥后2年生长期的树高年生长量表现为，生长类型好的群体对施肥有更好的持续促进高生长效应；生长类型差的群体，在施肥量相对少时高生长持续效应不明显，当施肥量较大时能有较好的树高年生长量持续生长效应。不同生长类型杉木胸径年生长量对施肥量的响应表现为，相同条件下，好的生长类型比差的生长类型有更好的胸径年生长量效果，施肥量相对不足时，差的生长类型群体胸径年生长持续效应逐渐衰退，好的生长类型对施肥有更好的持续促进生长效果，施肥量大对胸径年生长有更好的持续促进作用，与树高生长表现基本一致。研究表明，遗传品质好的杉木群体对立地适应能力越强，有更好的耐瘠薄能力和更好的年生长量。施肥措施对不同遗传品质生长类型杉木树高与胸径年生长量都有较好的促进效应，能有效恢复与提高杉木低产林分生长，为杉木低产与小老林林分改良提供理论指导。     

矮牡丹的树干解析

通过矮牡丹的树干解析,得出了以下结论：矮牡丹的地径的增长速度、株高的增长速度在植株生长３─９年时最快,以后逐渐变慢;株高生长的成熟龄为６─１２年,在植株生长９年以后,几个标本的生长速度都明显降低;在材积的增长过程中,１６年株龄的标本仍然没有达到成熟龄,连年生长曲线和平均生长曲线没有交点,表明矮牡丹的生长仍然处于旺盛阶段;立地条件对植株的生长也有着较大的影响,在立地条件较好的区域,植株明显生长比较快,而在立地条件较差的区域生长也差。     

呼伦贝尔沙地樟子松径向生长特征的VS模型模拟分析

利用Vaganov-Shashkin模型对呼伦贝尔地区4个样点的沙地樟子松标准化宽度年表进行模拟研究,在2000年以前时段拟合度较好,而2000年以后时段拟合度较差。进而选取2000年以前的模拟结果进行径向生长过程分析。结果表明: 呼伦贝尔沙地樟子松主要的生长季为每年的5—9月,温度对每年樟子松生长初期与末期具有显著影响,而在树木生长季旺盛期,土壤湿度的不足是制约树木生长的主要因素。极端窄年树木径向生长速率受土壤湿度的影响较极端宽年明显,生长季中期7—8月树木径向生长速率在宽窄年份均呈降低趋势,表明该时期沙地樟子松生长均受到不同程度的干旱胁迫。研究结果与我国半干旱地区树木年轮生理模型分析特征相符,模型对呼伦贝尔沙地樟子松径向生长模拟具有一定的适用性。     

丹江口水库凶猛鱼集团生长特性组型的聚类分析

选择体重-体长关系W=aLb中的回归系数a和回归指数b;阶段生长参数的年增长、相对增长率、体长生长比速、生长常数、生长指标和体重的年增重、相对增重率、体重生长比速、年增积量;一般生长型的渐近体长、渐近体重、生长系数、起点年龄、拐点年龄、拐点体重、拐点瞬时增重率等18个反映鱼类生长特性的指标,运用系统聚类方法,将丹江口水库5种主要凶猛鱼组成的集团,从生长特性的差异上划分为大、中、小3个组型,并对划分结果的具体应用和鱼类集团划分的依据等问题进行了讨论。       

钟萼木适宜生境选择与多年生造林效果探讨

应用“正态分布标准差分类法”划分钟萼木苗木不同生长类型并进行造林效果研究。结果表明，钟萼木苗木不同生长类型与杉木行带混交造林后，第一、二年在混交效应不明显的立地生境下，相邻生长类型树高年生长量差异相对较小，相隔一个生长类型以上，高年生长量都表现极显著差异，H6、H7生长类型的高年生长量大，对立地生境适应能力好，平均值及2个标准差以内生长类型是该树种群体生长状况的代表，年高生长量较低。该树种造林后第三年，平均值及2个标准差以内生长类型高年生长量在40～60 cm间，H7生长类型个体年高生长量达2.0 m以上。个体高生长表明，H7生长类型3年生高生长达4.0 m以上，其他生长类型3年生高生长在1.0～3.0 m，研究不同生长类型对造林生境的适应能力，为该树种人工培育与保护提供理论参考。     

秃杉引种幼龄生长规律初步研究

 引种研究表明,秃杉幼苗生长缓慢,苗期生长为双峰倒“W”形,春秋两季速生,盛夏趋于停滞。幼树造林初期生长缓慢,3年后加快;5—10年速生,生长量已接近或超过原产地。季节生长：春末夏初(5—6月)速生,6月出现峰值,盛夏遇高温减缓,生长呈单峰倒“V”形。树高昼夜生长：夜间>白天;阴雨天>阴天>晴天。引种地气温,相对湿度,净日照时数是影响幼龄秃杉生长的重要气象因子。秃杉幼树年生长与观察年树龄的关系可用数学模型y= a+bt表示;季节生长与观察月份的关系可用数学模型y=a+blnt表示。     

环境因子对广西红锥幼林生长的影响

为了探索环境因子对红锥生长的影响, 以广西红锥(Castanopsis hystrix Miq)人工幼林为研究对象, 运用Pearson相关性分析探讨环境因子对红锥幼林生长的影响。结果表明, 环境因子对红锥幼林生长有显著的影响, 不同环境条件试验点红锥生长速度差异显著(P＜0.05)。相关分析显示, 年降水量、海拔和年日照时数是影响红锥幼林生长的主要环境因子; 红锥幼林胸径生长与年日照时数存在显著正相关(P＜0.05)、与海拔和年降水量呈极显著负相关(r＜0); 红锥幼林树高生长与年日照时数存在极显著正相关(P＜0.01)、与海拔和年降水量呈显著负相关(r＜0)。研究结果揭示红锥人工林可以通过立地选择来达到丰产目的。     

Insects and light interact to mediate vine colonization of fast growing Microberlinia bisulcata tree seedlings in gaps of an African rain forest

Vines thrive in lowland tropical forests, yet the biotic factors underlying their colonization of host tree seedlings and saplings remain surprisingly understudied. Insect herbivores presumably could influence this process, especially where disturbance has opened the canopy (i.e., gaps)—temporary areas of higher primary productivity favoring the recruitment of vines and trees and invertebrates in forests—but their impact on vine colonization has never been experimentally tested. Using data from an insect herbivore exclusion (mesh-netting cages) experiment conducted in an African rain forest (Korup, Cameroon), I logistically modeled the probability of vines colonizing seedlings of three co-dominant species (Microberlinia bisulcata vs. Tetraberlinia bifoliolata and T. korupensis) in paired shaded understory and sunny gap locations (41 blocks across 80 ha, starting n = 664 seedlings) in a 1–2-yr period (2008–2009). Vine colonization occurred almost exclusively in gaps, occurring on 16% of seedlings there. Excluding herbivores in gaps doubled colonization of the light-demanding and faster growing M. bisulcata but had negligible effects on the two shade-tolerant, slower growing and less palatable Tetraberlinia species, which together were twice as susceptible to vines under natural forest gap conditions (controls). When protected from herbivores in gaps, more light to individual seedlings strongly increased vine colonization of M. bisulcata whereas its well-lit control individuals supported significantly fewer vines. These results suggest vines preferably colonize taller seedlings, and because light-demanding tree species grow faster in height with more light, they are more prone to being colonized in gaps; however, insect herbivores can mediate this process by stunting fast growing individuals so that colonization rates becomes more similar between co-occurring slow and fast growing tree species. Further influencing this process might be associational resistance or susceptibility to herbivores linked to host species’ leaf traits conferring shade-tolerant ability as seedlings or saplings. A richer understanding of how vines differentially influence forest regeneration and species composition may come from investigating vine–tree–herbivore interactions across light gradients, ideally via long-term studies and intercontinental comparisons. Abstract in French is available with online material.     

长白落叶松幼苗在受控条件下干物质积累的模拟

本文通过建立长白落叶松(Larix olgensis)幼苗在受控环境条件下的净光合速率与温度和CO2 等因子之间的关系,模拟了在受控条件下长白落叶松幼苗的日净光合速率进程与生长季中日干物质积累过程,并预测了在温度与CO2 浓度改变后干物质积累的变化。     

长白落叶松、日本落叶松和兴安落叶松幼苗光合作用特性比较研究

研究长白落叶松(Larix olgensis Herry.),日本落叶松(Larix kaempferi Carr.) 和兴安落叶松(Larix gmelinii Rupr.)当年生和一年生幼苗的光合作用日变化、季节变化和光响应曲线,结果表明：①三种植物中,长白落叶松、日本落叶松当年生和一年生幼苗和兴安落叶松当年生幼苗光合速率日变化都呈双峰曲线,具有明显的“午休”特征。兴安落叶松一年生幼苗的光合速率日变化呈单峰曲线。②日本落叶松的光饱和点 (LSP) 最高,兴安落叶松光补偿点（LCP）最低。③三种落叶松的一年生幼苗都是在生长中期表现出最大的光合能力。从年龄来看,落叶松当年生幼苗在生长初期和生长中期的光合能力要低于一年生幼苗,但在生长后期高于一年生幼苗。④从种来看,生长初期,当年生和一年生幼苗的最大净光合速率(P_max)均为日本落叶松＞兴安落叶松＞长白落叶松;生长中期,当年生幼苗的P_max规律与生长初期相似,一年生幼苗的P_max为长白落叶松＞日本落叶松＞兴安落叶松;生长后期,当年生幼苗的P_max为长白落叶松＞兴安落叶松＞日本落叶松,一年生幼苗的P_max与生长中期一年生幼苗的规律正好相反。通过分析我们得到结论：三个树种在生长季节相同阶段具有不同的光合特性;每个种不同年龄和生长季节不同阶段也表现出不同的光合特性;三个树种中,长白落叶松幼苗对光抑制引起的光合器官损伤的修复能力最强,日本落叶松次之,兴安落叶松最弱;日本落叶松幼苗较喜光,光合作用能力较强,不易发生光抑制,而兴安落叶松幼苗较耐阴。因此在育苗和造林时应考虑不同树种的光合特性调节最佳的光照条件。     

长白落叶松幼苗在受控条件下干物质积累的模拟

本文通过建立长白落叶松（Ｌａｒｉｘ ｏｌｇｅｎｓｉｓ）幼苗在受控环境条件下的净光合速率与温度和ＣＯ２等因子之间的关系,模拟了在受控条件下开白落叶松幼苗的日净光合速率进程与生长季中日干物质积累过程,并预测了在温度与ＣＯ２浓度改变后干物质积累的变化。     

Does growth correlate with turgor-induced elastic strain in stems? A re-evaluation of de Vries' classical experiments

The correlation between growth and turgor-induced elastic expansion was studied in hypocotyls of sunflower (Helianthus annuus) seedlings under various growth conditions. Turgor-induced elastic cell wall strain was greater in hypocotyls of faster growing seedlings, i.e. in etiolated versus light-grown ones. It also was higher in rapidly growing young seedlings as compared with nongrowing mature ones. However, analysis of the spatial distribution of elastic strain and growth demonstrated that their correspondence was only apparent. Profiles of elastic strain declined steadily from the top of the hypocotyls toward the basis, whereas the profiles of relative elemental growth rate along the hypocotyls showed maxima within the growing zones. In contrast to earlier hypotheses, we conclude that turgor-induced elastic cell wall strain and growth do not correlate precisely in growing hypocotyls.     

光质对绿豆幼苗叶片超微弱发光及叶绿素含量的影响

以绿豆幼苗为试材,测定其叶片超弱发光(UBE)及叶绿素含量在不同光质条件下的变化,并探讨两者之间的关系.结果表明,生长在不同光质下绿豆幼苗叶片的UBE及延迟发光衰减参数1/P都随着其生长不断增强,且生长在白光下绿豆幼苗的UBE是生长在其他光质(红、黄、蓝、绿)下幼苗的2倍以上,而红光、黄光和绿光处理之间无显著差异;生长在白光下的绿豆幼苗叶片叶绿素含量显著高于红、黄、蓝、绿光处理幼苗,而红光和黄光处理又显著高于蓝光和绿光处理.研究发现,光质对绿豆幼苗叶片超弱发光和叶绿素含量影响相似,绿豆幼苗叶片超弱发光可能与叶绿体的发育和光合作用有关.     

土壤结构与光照水平对秋茄某些生长和生理参数的影响

在香港的３个红树森样地即黄竹湾（沙土）、西径（沙壤土）和米埔（粘壤土）进行了土壤结构对秋茄（Kandelia candel(L.)Durce)生长和生理影响的研究,并在米埔比较了林内和林外秋茄幼苗的生长和生理参数以观察光照水平的效应。在沙土和沙壤土生长的１．５年秋茄幼苗比粘壤土具有较粗的基径的较高的总生物量,说明秋茄幼苗在沙土和沙壤土中比在粘壤土中生长更好。沙土１．５ 茄幼苗的叶片厚度分别为沙壤土和粘壤土的１．７５和２．０５倍,表明沙土中的秋茄幼苗具有旱生结构以维持体内水分。然而,沙土和沙壤土４．５年秋茄幼树的叶片厚度无显著差异,沙土和沙壤土中１．５年秋茄幼苗分配于根系的生物量比例约为５０％,高于粘壤土的值（约４０％）。沙土和沙壤土中１．５年的秋茄比粘壤土具有较低的叶绿素含量、根系活力、硝酸盐还原酶活性、过氧化物酶（ＰＯＸ）活性、超氧化物歧化酶（ＳＯＤ）活性及较高的丙二醛（ＭＤＡ）含量。米埔１．５年秋茄幼苗在红树林外比林内有更好的长势,具有更大的叶面积、特殊叶面积、叶片数量及生物量。林内幼苗具有较高叶绿素含量,较低叶绿素a/b比值,较高硝酸盐还原酶活性和较强的根系活力,林外幼苗的叶片ＰＯＸ和ＳＯＤ活性比林内的值稍高,ＭＤＡ含量比林内显著要高。     

Early emergence increases survival of tree seedlings in Central European temperate forests despite severe late frost

Global warming is expected to result in earlier emergence of tree seedlings that may experience higher damages and mortality due to late frost in spring. We monitored emergence, characteristics, and survival of seedlings across ten tree species in temperate mixed deciduous forests of Central Europe over one and a half year. We tested whether the timing of emergence represents a trade‐off for seedling survival between minimizing frost risk and maximizing the length of the growing period. Almost two‐thirds of the seedlings died during the first growing period. The timing of emergence was decisive for seedling survival. Although seedlings that emerged early faced a severe late frost event, they benefited from a longer growing period resulting in increased overall survival. Larger seedling height and higher number of leaves positively influenced survival. Seedlings growing on moss had higher survival compared to mineral soil, litter, or herbaceous vegetation. Synthesis. Our findings demonstrate the importance of emergence time for survival of tree seedlings, with early‐emerging seedlings more likely surviving the first growing period.     

Ectomycorrhizal colonization of naturally regenerating <Emphasis Type="Italic">Pinus sylvestris</Emphasis> L. seedlings growing in different micro-habitats in boreal forest

We investigated the species richness and composition of ectomycorrhizal (EM) fungi colonizing Pinus sylvestris L. seedlings naturally regenerating in boreal forest, in three different microhabitats: on forest ground, on decaying stumps, and within moss layer on erratic boulders. We tested the hypothesis that habitat differences would affect the composition of the EM community of regenerating pine seedlings. In total, 16 EM species were detected, from which none occurred on seedlings growing in all three microhabitats. Piloderma croceum and Cenococcum geophilum were common for seedlings growing in forest ground and on boulders, while Tricholoma aestuans and Suillus luteus were shared between seedlings growing on forest ground and decaying stumps. EM species richness and composition were strikingly different between seedlings regenerating in different microhabitats. Results are discussed as a function of dispersal and niche differentiation of EM fungi.     

Induction of heat shock-like proteins in Vigna sinensis seedlings growing under ultraviolet-B (280-320 nm) enhanced radiation

The effect of ultraviolet-B (UV-B) enhanced fluorescent radiation on protein profile and protein synthesis has been investigated in Vigna sinensis L. cv. Walp seedlings growing at various temperatures. In seedlings growing at 30°C, UV-B radiation decreased the level of several proteins as seen in Coomassie brilliant blue stained gel. However, fluorography of the same gel indicates induction of three sets of proteins in the range of 70. 53 and 16 k Da. Such induction under UV-B enhanced radiation resembled that found after heat shock treatments. In seedlings at 10 and 20°C, induction of such proteins varied both qualitatively and quantitatively. At 40°C. UV-B enhanced radiation caused a cumulative effect with temperature. Strong induction of specific proteins by UV-B radiation in seedlings growing under normal temperature indicates a possible protective role.