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1.
为研究物种在不同群落中光合生理特征的变化,以亚高寒草甸围封恢复地为研究对象,对样地内3个不同组成群落进行样方调查,测定了物种高度及各群落垂直方向上光照强度以及群落中3个共有种披碱草(Elymus dahuricus)、刺儿菜(Cirsium setosum)和紫花苜蓿(Medicago sativa)的净光合速率(Aarea)、叶片氮含量(Nmass)、比叶重(LMA)及光合氮利用效率(PNUE)。结果表明:(1)3个样地的群落组成有明显的差异,豆科植物的增多可以一定程度上改善群落氮养分状况,但植物叶片Nmass还受到群落优势种竞争的影响。(2)同一物种在不同群落的高度不同,不同群落垂直方向上光照强度也不相同,导致同一物种在不同群落中能够获得的光照强度有一定差异。(3)在养分、光照强度有差异的情况下,不同植物的Aarea、LMA及PNUE在不同群落中的变化趋势不尽相同,而Narea与Aarea的关系在总体上、群落间及物种间变化不大,基本上显示了较强的正相关关系。由此可见,群落组成、结构引起的光照及氮素差异是导致同一物种光合生理特征在不同群落中变化的重要因素,但不同物种光合生理特征对光照及氮素变化的响应不同。 相似文献
2.
Do higher resource capture ability and utilization efficiency facilitate the successful invasion of native plants? 总被引:2,自引:0,他引:2
Xing-Yan Shen Shao-Lin Peng Bao-Ming Chen Jun-Xiao Pang Lei-Yi Chen Hao-Ming Xu Yu-Ping Hou 《Biological invasions》2011,13(4):869-881
The great damage caused by native invasive species on natural ecosystems is prompting increasing concern worldwide. Many studies
have focused on exotic invasive species. In general, exotic invasive plants have higher resource capture ability and utilization
capacity, and lower leaf construction cost (CC) compared to noninvasive plants. However, the physiological mechanisms that
determine the invasiveness of native plants are poorly understood. We hypothesized that native invaders, like exotic invaders,
may have higher resource capture ability and utilization efficiency compared to native noninvaders. To test this hypothesis,
ecophysiological traits including light-saturated photosynthetic rate (Amax), specific leaf area (SLA), photosynthetic nitrogen use-efficiency (PNUE), photosynthetic energy-use efficiency (PEUE), and
mass-based and area-based leaf construction cost (CCmass and CCarea) were measured. We compared the above traits between three pairs of native invasive and noninvasive native species, and between
three pairs of exotic invasive and noninvasive species in Guangzhou, southern China. Our results showed that the native invaders
had higher Amax, SLA, PNUE, PEUE and lower CCmass, CCarea, compared to native noninvaders and that these traits were also found in the exotic invaders. PNUE and PEUE in the native
invaders were 150.3 and 129.0% higher, respectively, than in noninvasive native species, while these same measures in exotic
invaders were 43.0 and 94.2% higher, respectively, than in exotic noninvasive species. The results indicated that native invaders
have higher resource capture ability and resource utilization efficiency, suggesting that these traits may be a common biological
foundation underlying successful invasion by both native and exotic invasives. 相似文献
3.
Photosynthesis-nitrogen relations in Amazonian tree species 总被引:18,自引:0,他引:18
The relationships between leaf nitrogen (N), specific leaf area (SLA) (an inverse index of leaf thickness or density), and photosynthetic capacity (Amax) were studied in 23 Amazonian tree species to characterize scaling in these properties among natural populations of leaves of different ages and light microenvironments, and to examine how variation within species in N and SLA can influence the expression of the Amax-to-N relationship on mass versus area bases. The slope of the Amax-N relationship, change in A per change in N (mol CO2 gN-1 s-1), was consistently greater, by as much as 300%, when both measures were expressed on mass rather than area bases. The x-intercept of this relationship (N-compensation point) was generally positive on a mass but not an area basis. In this paper we address the causes and implications of such differences. Significant linear relationships (p<0.05) between mass-based leaf N (Nmass) and SLA were observed in 12 species and all 23 regressions had positive slopes. In 13 species, mass-based Amax (Amass) was positively related (p<0.05) with SLA. These patterns reflect the concurrent decline in Nmass and SLA with increasing leaf age. Significant (p<0.05) relationships between area-based leaf N (Narea) and SLA were observed in 18 species. In this case, all relationships had negative slopes. Taken collectively, and consistent in all species, as SLA decreased (leaves become thicker) across increasing leaf age and light gradients, Nmass also decreased, but proportionally more slowly, such that Narea increased. Due to the linear dependence of Amass on Nmass and a negative 4-intercept, thicker leaves (low SLA) therefore tend, on average, to have lower Nmass and Amass but higher Narea than thinner leaves. This tendency towards decreasing Amass with increasing Narea, resulting in a lower slope of the Amax-N relationship on an area than mass basis in 16 of 17 species where both were significant. For the sole species exception (higher area than mass-based slope) variation in Narea was related to variation in Nmass and not in SLA, and thus, these data are also consistent with this explanation. The relations between N, SLA and Amax explain how the rate of change in Amax per change in N can vary three-fold depending on whether a mass or area mode of expression is used. 相似文献
4.
Yoshihiko Sakanishi Hiromi Kasai Koichiro Enomoto Masashi Toda Jiro Tanaka 《Phycological Research》2019,67(4):253-260
Trade‐offs are considered key to understanding mechanisms supporting the coexistence of multiple plant species. Thus, understanding the mechanisms underlying trade‐offs is expected to contribute to conservation and management of macroalgal beds composed of diverse macroalgae of rocky shore ecosystems. To test the occurrence of trade‐offs between productivity and thallus toughness as well as pair‐wise thallus trait relationships that are expected to indirectly relate to any trade‐offs, traits and relationships for 13 species of macroalgae from the central area along the Japan Sea coast of Honshu, Japan were examined. In each species we examined for photosynthetic capacity per unit biomass (as Amass) and nitrogen (i.e., photosynthetic nitrogen‐use efficiency, PNUE), nitrogen content (as Nmass), thallus mass per unit thallus area (as TMA) and force required to penetrate the thallus (as Fp, a common index of leaf toughness in land plants by punch test). A significant negative correlation indicating a trade‐off between productivity and thallus toughness was found between Amass or PNUE and Fp. Pair‐wise relationships that were expected to indirectly relate to the trade‐off were as follows. Amass was positively correlated with Nmass. Thalli with high Nmass extensively utilizing nitrogen in the photosynthetic parts, and consequently exhibiting elevated metabolic rates. Moreover, thalli with high Nmass tended to be associated with low TMA, and Nmass decreased with increasing TMA. A significant negative correlation was observed between TMA and Amass or PNUE because of the linkage of high Amass or PNUE with high Nmass and high Nmass associated with low TMA, while a significant positive correlation was observed between TMA and Fp. The two correlations indicate a physiological and structural trade‐off, which underlies the interdependency of thallus traits. Results of multivariate analyses also indicated that the thallus traits interdependently vary across a single axis based on the trade‐off. 相似文献
5.
Seasonal differences in leaf-level physiology give lianas a competitive advantage over trees in a tropical seasonal forest 总被引:1,自引:0,他引:1
Lianas are an important component of most tropical forests, where they vary in abundance from high in seasonal forests to
low in aseasonal forests. We tested the hypothesis that the physiological ability of lianas to fix carbon (and thus grow)
during seasonal drought may confer a distinct advantage in seasonal tropical forests, which may explain pan-tropical liana
distributions. We compared a range of leaf-level physiological attributes of 18 co-occurring liana and 16 tree species during
the wet and dry seasons in a tropical seasonal forest in Xishuangbanna, China. We found that, during the wet season, lianas
had significantly higher CO2 assimilation per unit mass (A
mass), nitrogen concentration (N
mass), and δ13C values, and lower leaf mass per unit area (LMA) than trees, indicating that lianas have higher assimilation rates per unit
leaf mass and higher integrated water-use efficiency (WUE), but lower leaf structural investments. Seasonal variation in CO2 assimilation per unit area (A
area), phosphorus concentration per unit mass (P
mass), and photosynthetic N-use efficiency (PNUE), however, was significantly lower in lianas than in trees. For instance, mean
tree A
area decreased by 30.1% from wet to dry season, compared with only 12.8% for lianas. In contrast, from the wet to dry season mean
liana δ13C increased four times more than tree δ13C, with no reduction in PNUE, whereas trees had a significant reduction in PNUE. Lianas had higher A
mass than trees throughout the year, regardless of season. Collectively, our findings indicate that lianas fix more carbon and
use water and nitrogen more efficiently than trees, particularly during seasonal drought, which may confer a competitive advantage
to lianas during the dry season, and thus may explain their high relative abundance in seasonal tropical forests. 相似文献
6.
Guohong Wang 《植被学杂志》2007,18(4):563-570
Question: Is there any generality in terms of leaf trait correlations and the multiple role of leaf traits (response to and/or effect on) during secondary succession? Location: A secondary successional sere was sampled at four different ages since abandonment from several years to nearly 150 years on the Loess Plateau of northwestern China. Method: Specific leaf area (SLA), leaf mass per area (LMA), leaf nitrogen (Nmass, Narea), leaf phosphorus (Pmass, Parea) and leaf dry matter content (LDMC) were measured for all species recorded in the successional sere. Above‐ground net primary productivity (ANPP) and specific rate of litter mass loss (SRLML) were measured as surrogates for ecosystem properties. Soil total carbon (C) and nitrogen (N) were measured in each stage. Leaf traits were related to ecosystem properties and soil nutrient gradients, respectively. Results: LMA is correlated with Narea and Parea' and negatively with Nmass. Correlation between Narea and Parea was higher than between Nmass and Pmass. At the community level, field age, community hierarchy and their interaction explain 64.4 ‐ 93.5% of the variation in leaf traits. At the species level, field age explains 22.4 ‐ 45.5% of the variation in leaf traits (excl. Parea) while plant functional group has a significant effect only for Nmass. LDMC is correlated with ANPP and negatively with SRLML; Pmass is correlated with SRLML. Conclusions: Mean values of LMA, Nmass and Narea are close to the worldwide means, suggesting that large‐scale climate has a profound effect on leaf mass and leaf nitrogen allocation, while environmental gradients represented by succession have little influence on leaf‐trait values. Correlations between leaf traits, such as LMA‐Narea, LMA‐Parea and LMA‐Nmass shown in previous studies, are confirmed here. Although none of the leaf traits is proved to be both a response trait and an effect trait independent of time scale and community hierarchy, mass‐based leaf N is likely a sensitive response trait to soil C and N gradients. In addition, LDMC can be a marker for ANPP and SRLML, while mass‐based leaf P can be a marker for SRLML. 相似文献
7.
入侵种银胶菊和三叶鬼针草与本地种气体交换特性的比较 总被引:1,自引:0,他引:1
以菊科入侵植物银胶菊(Parthenium hysterophorus)和三叶鬼针草(Bidens pilosa)以及与其共生的菊科本地植物小蓟(Cirsium setosum)为对象,比较了3种植物气体交换参数和叶片特性的差异。结果表明,银胶菊和三叶鬼针草的净光合速率(net photosynthetic rate,P_n)、叶绿素含量、比叶面积(specific leaf area,SLA)、叶片单位质量P含量(leaf P content per unit mass,P_(mass))、光合能量利用效率(photosynthetic energy use efficiency,PEUE)和光合氮利用效率(photosynthetic nitrogen use efficiency,PNUE)均显著高于小蓟。植物叶片P_n与水分利用效率(water use efficiency,WUE)、叶片P_(mass)、SLA呈极显著正相关,植物叶片单位质量N含量(leaf P content per unit mass,N_(mass))与叶片SLA、单位质量建成成本(leaf construction cost per unit mass,CC_(mass))、叶绿素含量呈极显著正相关。与本地植物相比,较高的气体交换参数和叶片生化指标有可能是银胶菊和三叶鬼针草成功入侵的原因之一。 相似文献
8.
E. Novriyanti M. Watanabe K. Makoto T. Takeda Y. Hashidoko T. Koike 《Photosynthetica》2012,50(2):273-281
The ecophysiological traits of acacia and eucalypt are important in assessing their suitability for afforestation. We measured the gas-exchange rate, the leaf dry mass per area (LMA) and the leaf nitrogen content of two acacia and four eucalypt species. Relative to the eucalypts, the acacias had lower leaf net photosynthetic rate (P N), lower photosynthetic nitrogen-use efficiency (PNUE), higher water-use efficiency (WUE), higher LMA and higher leaf nitrogen per unit area (N area). No clear differences were observed within or between genera in the maximum rate of carboxylation (V cmax) or the maximum rate of electron transport (J max), although these parameters tended to be higher in eucalypts. PNUE and LMA were negatively correlated. We conclude that acacias with higher LMA do not allocate nitrogen efficiently to photosynthetic system, explaining why their P N and PNUE were lower than in eucalypts. 相似文献
9.
植物叶功能性状与环境因子的关系是近10年来植物生态学的研究热点。该文以广泛分布于青藏高原干旱、半干旱草地的优势植物种紫花针茅(Stipa purpurea)为研究对象, 沿降水梯度(69-479 mm)系统测定了日土、改则、珠峰、当雄和纳木错5个调查地点紫花针茅比叶面积(SLA)、单位重量和单位面积叶氮含量(Nmass, Narea)、叶密度和厚度等叶功能性状以及土壤全氮含量等因子, 试图验证干旱胁迫地区同一物种内SLA-Nmass关系沿降水梯度的策略位移现象是否具有普遍性, 并对是否出现策略位移现象提出可能的解释。研究结果表明: 1) SLA和Nmass与生长季温度和降水以及土壤全氮含量均没有显著关系, SLA与Nmass的关系在干旱半干旱区(年降水/蒸发比< 0.11)与半湿润区(年降水/蒸发比> 0.11)之间并没有出现典型的位移现象; 2)叶密度是决定半湿润区SLA变化的主导因子, 而叶厚度则是干旱半干旱区SLA变化的控制因子, 两者与SLA均呈负相关, 随着温度增加或降水减少, 叶厚度增加而叶密度降低, 导致SLA随温度和降水变化不明显; 3)半湿润区的叶密度增加引起Narea增加, 而干旱半干旱区的叶厚度增加并没有造成Narea的显著变化, 导致Narea沿降水梯度没有显著变化; 4)紫花针茅地上生物量与Narea具有显著正相关关系, 表明Narea的增加有助于提高植被生产力。结果表明, 在干旱胁迫下, 植物通过增加叶厚度来维持不变的Narea可能有助于保持与较湿润地区相似的光合生产和水分利用效率。叶厚度和叶密度对比叶面积的相对影响在干旱半干旱区与半湿润区之间发生转变, 这为进一步检测高寒草地植被的水分限制阈值提供了新思路。 相似文献
10.
Forest floor of larch species often provides growth habitat for many kinds of understory species because of relatively sparse
structure in a larch canopy. A rich flora of forest understory species may play an essential role in maintaining fertility
of a larch stand. An attempt was made to evaluate photosynthetic nitrogen use efficiency (PNUE) of many understory and overstory
species according to their Raunkiaer lifeform. By studying 72 perennial deciduous species in a larch plantation in northeast
China, marked photosynthetic differences between phanerophytes (Ph) and other three lifeforms of chamaephytes (Ch), hemicryptophytes
(He), and cryptophytes (Cr) were found, with marginal differences found among Ch, He, and Cr. Ph species had much lower PNUE,
and much lower values of rate of nitrogen allocation to chlorophyll (Chl./N) and nitrogen allocation to carboxylation processes
(V
cmax/N) were concurrently observed in Ph compared with the other three lifeforms. Ph had much lower leaf nitrogen per unit of
projection area (N
area) and specific leaf area (SLA, cm2 g–1). At lower SLA, for Ph species the change of PNUE with SLA was small, but these changes became very large at higher SLA for
Ch, He, and Cr species. Our findings indicate that leaf morphological change is important for clarifying photosynthesis differences
among species with different lifeform. 相似文献
11.
以漓江水陆交错带为研究区,分两个条带分别量测了适生植物的5个叶性状指标:最大净光合速率(A_(max))、比叶重(LMA)、单位质量叶片全氮含量(N_(mass))、单位质量叶片全磷含量(P_(mass))、单位质量叶片全钾含量(K_(mass))。研究重度淹没带与微度淹没带不同功能型植物叶性状间的差异,分析并讨论重度淹没带叶性状间的关系与全球尺度是否存在差异,探究重度淹没带植物对水淹生境的生理响应机制。结果如下:(1)重度淹没带植物叶片的A_(mass)、N_(mass)、P_(mass)显著高于微度淹没带。(2)乔木、灌木叶片的LMA均显著高于草本植物,而A_(mass)、PPUE均显著低于草本植物。(3)重度淹没带草本叶性状指标的N_(mass)、P_(mass)、PNUE均显著高于微度微度淹没带,而乔木、灌木的叶性状在两个条带的差异则不显著。(4)重度淹没带植物叶性状关系与全球尺度基本一致,其植物叶片具有低LMA,高A_(mass)、Nmas s、P_(mass)。分析可知,重度淹没带植物在出露期提高叶片光合效率及相关营养水平可能是其适应水淹胁迫特殊生境的关键策略之一;不同功能型植物对同一环境的适应能力存在一定的差异,草本对于水淹环境的响应更为积极,适应能力更好;重度淹没带也存在叶经济谱,其植物在经济谱中属于"快速投资-收益"型物种。 相似文献
12.
分析广西猫儿山不同海拔常绿和落叶树种的光合作用-氮关系,探讨光合氮利用效率(PNUE)是否受到叶片习性和海拔的影响。落叶树种的PNUE都显著高于常绿树种,这与前者有较低的比叶重(LMA)和较高的单位叶重光合速率(Amass)、氮含量和气孔导度(gs)有密切关系。高海拔树种的PNUE显著低于中低海拔树种的PNUE,这与前者较高的LMA和较低的Amass和gs相关。PNUE和相关的叶片特征的主成分分析表明常绿-落叶树种和低海拔-中海拔-高海拔树种的分布是一个自然过渡的过程。此外,PNUE与土壤碳:氮比没有显著相关性,但与年均温正相关,这表明温度气候是调节PNUE沿海拔变化的主要环境因素。因此,这种叶片习性和温度气候调节的PNUE变化可能是调节猫儿山常绿树种沿海拔形成双峰分布的一种机制。 相似文献
13.
Zhi-Jie Guan Shi-Bao Zhang Kai-Yun Guan Shu-Yun Li Hong Hu 《Journal of plant research》2011,124(2):289-298
Paphiopedilum and Cypripedium are closely related in phylogeny, but have contrasting leaf traits and habitats. To understand the divergence in leaf traits
of Paphiopedilum and Cypripedium and their adaptive significance, we analyzed the leaf anatomical structures, leaf dry mass per area (LMA), leaf lifespan
(LL), leaf nitrogen concentration (N
mass), leaf phosphorus concentration (P
mass), mass-based light-saturated photosynthetic rate (A
mass), water use efficiency (WUE), photosynthetic nitrogen use efficiency (PNUE) and leaf construction cost (CC) for six species.
Compared with Cypripedium, Paphiopedilum was characterized by drought tolerance derived from its leaf anatomical structures, including fleshy leaves, thick surface
cuticles, huge adaxial epidermis cells, lower total stoma area, and sunken stomata. The special leaf structures of Paphiopedilum were accompanied by longer LL; higher LMA, WUE, and CC; and lower N
mass, P
mass, A
mass, and PNUE compared with Cypripedium. Leaf traits in Paphiopedilum helped it adapt to arid and nutrient-poor karst habitats. However, the leaf traits of Cypripedium reflect adaptations to an environment characterized by rich soil, abundant soil water, and significant seasonal fluctuations
in temperature and precipitation. The present results contribute to our understanding of the divergent adaptation of leaf
traits in slipper orchids, which is beneficial for the conservation of endangered orchids. 相似文献
14.
桉树-乡土树种混交林在提高林分生产力和生态系统功能等方面具有较大潜力。该研究以南亚热带4种桉树-乡土树种混交林(桉树与乡土树种混交比例分别为5:5、6:4、7:3、8:2)和桉树纯林为研究对象,研究了3种优势乡土树种华润楠(Machilus chinensis)、阴香(Cinnamomum burmannii)、灰木莲(Manglietia glauca)和速生树种尾叶桉(Eucalyptus urophylla)的叶片生理、结构和化学性状在不同比例混交林中的差异。结果表明,4优势造林树种的叶片性状存在明显的种间差异,其中灰木莲的比叶面积(SLA)、光合磷利用效率(PPUE)、单位质量叶片最大光合速率(Amass)和蒸腾速率(Tmass)以及叶片养分含量最高,说明灰木莲采取资源获取型的生态策略;尾叶桉的SLA、Amass、Tmass及叶片养分含量最低,但具有最高的PPUE,说明尾叶桉兼顾了资源获取型和保守型的物种特征。灰木莲与尾叶桉在SLA、Amass、Tmass 相似文献
15.
Spatial and temporal variations in light-saturated photosynthetic capacity and needle nitrogen (N) content were investigated
in one 8 m tall Japanese cedar (Cryptomeria japonica D. Don) canopy for a full year. The photosynthetic capacity and needle N content in various layers of the canopy were measured
every month. Temporal variations in photosynthetic capacity and needle N content expressed on a projected-area basis (Parea, Narea) were similar. Furthermore, both Parea and Narea decreased with increasing depth from the top of the canopy on each sampling date. As a consequence, a significant correlation
was observed between Narea and Parea. Temporal variations in photosynthetic capacity and needle N content expressed on a mass basis (Pmass, Nmass) were also similar. Pmass also decreased with increasing canopy depth. However, in contrast to Narea, there was only a slight decrease in Nmass with increasing canopy depth. Hence, the correlation between Nmass and Pmass was lower than the projected-area value. Because Narea was highly correlated with the needle mass per projected-area (NMA), the spatial variation in Narea (and therefore Parea) in the canopy is attributed to the variation in NMA, which decreases as the depth from the top of the canopy increases.
Furthermore, the slope of the linear regression between Narea and NMA differed between sampling dates, indicating that the temporal variations in Narea (and therefore Parea) are strongly influenced by Nmass. For most of the sampling dates, a linear regression between Narea and Parea tends to converge into a single line segment. However, on several sampling dates, there was a pronounced decline in Parea below this line segment. This reduction in Parea, which does not accompany a reduction in Narea, seems to be attributable to stomatal limitations induced by the low soil
temperature in winter and early spring. 相似文献
16.
Marcus V. Cianciaruso Igor A. Silva Lilian T. Manica João Paulo Souza 《Basic and Applied Ecology》2013,14(5):404-412
Plant species with a high leaf life span (LLS) commonly have a low specific leaf area (SLA), leaf nitrogen per unit mass (N), and phosphorous concentration (P), whereas species with low LLS have a high SLA, N and P. However, LLS tends to be longer in species growing in low-nutrient soils and, therefore, differences in LLS and other leaf traits may not be consistent with a plant classification according to leaf habit. Here we investigated whether leaf habit is consistent with leaf economic spectrum trade-offs in cerrado (a Neotropical savanna) woody species. We analyzed the SLA, N and P of 125 woody species with a distinct leaf habit (deciduous, semideciduous, brevideciduous or evergreen). We also gathered data on the LLS (33 species), maximum net photosynthesis per leaf area (Aarea, 56 species) and per leaf mass (Amass, 31 species), comprising the most extensive database analyzed so far for the cerrado. Differences among leaf habit groups were tested using generalized linear mixed models and ANOVA. We did not find differences in SLA and N among species with a distinct leaf habit, but deciduous species had a higher leaf P concentration than evergreens. Species did not differ in LLS and Amass, but Aarea varied among groups. Semideciduous species had higher Aarea values than deciduous and brevideciduous species, but all other groups had similar Aarea values. Because of the small difference in the LLS, SLA, leaf N, leaf P and maximum net photosynthesis, we argue that deciduous, brevideciduous, semideciduous and evergreen species may not constitute different functional groups in cerrado woody species. 相似文献
17.
Spatial patterns of photosynthetic characteristics and leaf physical traits of plants in the Loess Plateau of China 总被引:1,自引:0,他引:1
The spatial patterns of photosynthetic characteristics and leaf physical traits of 171 plants belonging to nine life-forms
or functional groups (trees, shrubs, herbs, evergreen trees, deciduous trees, C3 and C4 herbaceous plants, leguminous and non-leguminous species) and their relationships with environmental factors in seven sites,
Yangling, Yongshou, Tongchuan, Fuxian, Ansai, Mizhi and Shenmu, ranging from south to north in the Loess Plateau of China
were studied. The results showed that the leaf light-saturated photosynthetic rate (Pmax), photosynthetic nitrogen use efficiency (PNUE), chlorophyll content (Chl), and leaf mass per area (LMA) of all the plants
in the Loess Plateau varied significantly among three life-form groups, i.e., trees, shrubs and herbs, and two groups, i.e.,
evergreen trees and deciduous trees, but leaf nitrogen content differed little among different life-form groups. For the 171
plants in the Loess Plateau, leaf Pmax was positively correlated with PNUE. The leaf nitrogen content per unit area (Narea) was positively correlated but Chl was negatively correlated with the LMA. When controlling the LMA, the Narea was positively correlated with the Chl (partial r = 0.20, P < 0.05). With regard to relationships between photosynthetic characteristics and leaf physical traits, the Pmax was positively correlated with N
area, while the PNUE was positively correlated with the Chl and negatively correlated with the Narea and LMA. For all the species in the Loess Plateau, the PNUE was negatively correlated with the latitude and annual solar
radiation (ASR), but positively correlated with the mean annual rainfall (MAR) and mean annual temperature (MAT). With regard
to the leaf physical traits, the leaf Chl was negatively correlated with the latitude and ASR, but positively correlated with
the MAR and MAT. However, the Narea and LMA were positively correlated with the latitude and ASR, but negatively correlated with the MAR and MAT. In general,
leaf Narea and LMA increased, while PNUE and Chl decreased with increases in the latitude and ASR and decreases in MAR and MAT.
Electronic supplementary material The online version of this article () contains supplementary material, which is available to authorized users. 相似文献
18.
叶功能性状与植物的生长对策及资源利用效率密切相关,研究叶功能性状沿气候梯度的变异特征能为理解植物对气候变化的响应机制提供一种简便可行的测定指标。以我国西北荒漠地区广泛分布的唐古特白刺(Nitraria tangutorum)为研究对象,对其比叶面积(SLA)、单位质量和单位面积叶氮含量(Nmass、Narea)、单位质量和单位面积叶建成成本(CCmass、CCarea)进行测定,分析这些叶功能性状及性状相关关系沿气候梯度的变异特征。结果表明,唐古特白刺叶功能性状(CCarea除外)在气候梯度下存在显著差异,其中,温度是决定唐古特白刺SLA变化的主要因子,SLA随着温度的增加而增加;降水和温度对唐古特白刺Nmass、Narea和CCmass均有显著影响,Nmass和Narea随着降水和温度的增加而降低,而CCmass呈增加趋势。沿气候梯度,唐古特白刺SLA-Nmass、CCmass-Nmass和CCarea-Narea的线性正相关关系发生平移,导致在相同SLA、CCmass和CCarea下,降水和温度较低的地区具有更高的Nmass和Narea。这一结果表明唐古特白刺能通过调节叶功能性状之间的关系来适应气候的变化,并形成性状间的最佳功能组合。 相似文献
19.
Leaf nitrogen content per area (Narea) is a good indicator of assimilative capacity of leaves of deciduous broad-leaved trees. This study examined the degrees of increase in Narea in response to canopy openings as leaf mass per area (LMA) and leaf nitrogen content per mass (Nmass) in saplings of eight deciduous broad-leaved tree species in Hokkaido, northern Japan. Five of the species were well-branched species with a large number of small leaves (lateral-growth type), and the other three species were less-branched species with a small number of large leaves (vertical-growth type). The degrees of increase in Narea were compared between the two crown types. In closed-canopy conditions, leaves of the vertical-growth species tended to have a lower LMA and higher Nmass than those of the lateral-growth species, which resulted in similar Narea for both. LMA increased in canopy openings in the eight species, and the degrees of increase were not largely different between the lateral- and vertical-growth species. On the contrary, Nmass was unchanged in canopy openings in the eight species. As a result, Narea of each species increased in canopy openings in proportion to the increase in LMA, and the degrees of increase in Narea were similar in the lateral- and vertical-growth species. Therefore, this study showed that the degrees of increase in Narea were not correlated with the crown architecture (i.e., the lateral- and vertical-growth types). 相似文献
20.
Leaf physiological and gas-exchange traits of a summer-green herbaceous perennial, Parasenecio yatabei, growing along a stream were examined in relation to leaf age. In its vegetative phase, the aerial part of this plant consists
of only one leaf and provides an ideal system for the study of leaf longevity. Volumetric soil water content (SWC) decreased
with increasing distance from the stream, whereas relative light intensity was nearly constant. The light-saturated net CO2 assimilation rate (A
sat) and leaf stomatal conductance (gs) were approximately 1.5-fold and 1.4-fold higher, respectively, in the lower slope near
the mountain stream than in the upper slope far from the mountain stream. The lifespan of aerial parts of vegetative plants
significantly increased with decreasing SWC. The leaf mass-based nitrogen content of the leaves (N
mass) was almost constant (ca. 2.2%); however, the maximum carboxylation rate by ribulose-1,5-biphosphate carboxylase/oxygenase
(rubisco) (V
cmax) and photosynthetic nitrogen use efficiency (PNUE, A
sat/N
area) decreased more slowly in the upper slope than in the lower slope. The higher leaf photosynthetic activity of P. yatabei plants growing lower on the slope leads to a decrease in V
cmax and PNUE in the early growing season, and to a shorter leaf lifespan. 相似文献