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1.
重庆石灰岩地区主要木本植物叶片性状及养分再吸收特征 总被引:5,自引:0,他引:5
以重庆石灰岩地区15种常绿木本植物和14种落叶木本植物为研究对象,对两种生活型植物叶片衰老前后叶干物质含量(LDMC)、比叶面积(SLA)和叶片厚度(LT)进行了比较,并采用不同的计算方法(单位质量叶片养分含量、单位面积叶片养分含量)分析了两类植物叶片衰老前后养分含量及再吸收特征,最后对养分再吸收效率与其他叶性状因子之间的关系进行了相关分析。结果表明:常绿植物成熟叶LDMC、LT及衰老叶LT显著低于落叶植物,落叶植物成熟叶和衰老叶SLA均显著高于常绿植物(P0.05);基于单位质量叶片计算的养分含量,常绿植物成熟和衰老叶N、P量均低于落叶植物,而基于单位面积叶片计算的N、P含量则表现出相反的趋势;基于不同方法计算的N、P再吸收效率差异不明显,其中常绿植物基于单位质量叶片养分含量计算的N、P平均再吸收效率为39.42%、43.79%,落叶植物的为24.08%、33.59%;常绿和落叶植物N、P再吸收效率与LDMC、SLA、LT和成熟叶N、P含量之间没有显著相关性,但与衰老叶养分含量存在显著负相关(P0.05)。研究发现,无论是常绿植物还是落叶植物,衰老叶N、P含量均较低,表明石灰岩地区植物具有较高的养分再吸收程度。 相似文献
2.
中国东部南北样带森林优势植物叶片的水分利用效率和氮素利用效率 总被引:3,自引:0,他引:3
通过测定中国东部南北样带主要森林生态系统中10种优势植物(兴安落叶松、蒙古栎、水曲柳、紫椴、色木槭、红松、杉木、木荷、马尾松、锥栗)叶片的碳氮含量(Cmass、Nmass)、同位素丰度(δ13C、δ15N)以及光合响应曲线,分析了不同优势植物叶片的水分利用效率和氮素利用效率之间的差异及其相互关系.结果表明:不同生活型植物叶片的Nmass和δ15N差异显著,表现为阔叶植物>针叶植物,落叶植物>常绿植物;最大光合速率(Pnmax)表现为针叶植物>阔叶植物,落叶植物>常绿植物;植物叶片的瞬时水分利用效率(WUEi)和长期水分利用效率(WUE)均表现为阔叶植物>针叶植物,常绿植物>落叶植物;植物叶片的瞬时氮素利用效率(NUEi)和长期氮素利用效率(NUE)则表现出相反的规律,且常绿植物和落叶植物叶片的NUE差异显著;WUEi和WUE之间相关性不显著,而NUEi和NUE之间呈显著正相关.植物叶片的水分利用效率与氮素利用效率显著负相关.两种资源利用效率均受植物生活型的影响,并且存在一定的制约关系. 相似文献
3.
短命植物是荒漠生态系统的重要组成部分。为了解短命植物叶片N、P化学计量特征随生长季变化的特点,选择古尔班通古特沙漠6种优势短命植物(3种一年生短命植物,3种多年生类短命植物)为研究对象,对比了2种生活型短命植物叶片N、P化学计量特征随生长季变化特点。结果表明,3种一年生短命植物尖喙牻牛儿苗(Erodium oxyrrhynchum)、小花荆芥(Nepeta micrantha)以及条叶庭芥(Alyssum linifolium)N含量平均值(±标准差)分别为(11.23±7.16)、(14.11±6.38)和(10.85±6.14)mg·g–1;P含量平均值分别为(2.82±0.73)、(3.12±1.24)和(3.43±0.55)mg·g–1;3种多年生类短命植物独尾草(Eremurus chinensis)、雅葱(Scorzonera pusilla)和簇花芹(Soranthus meyeri)N含量的平均值分别为(19.97±5.94)(15.08±4.01)和(17.94±9.03)mg·g–1;P含量平均值分别为(3.55±0.83)、(2.73±1.11)和(5.03±0.65)mg·g–1。由此可见,短命植物在生长过程中叶片N-P化学计量特征存在一定差异。各物种N、P含量在生长初期都大于其它生长季节,在生长旺季随叶片生物量增加,N、P含量呈下降趋势;而在生长末季N、P含量又有所回升。相关性分析表明,不同生活型短命植物元素间的关系存在差异,但同一生活型短命植物元素间的关系并无显著差异,体现了种内一致性。 相似文献
4.
以湘西南石漠化地区灌丛植物叶片为研究对象,分析了不同功能群植物以及3种不同石漠化程度(轻度、中度、重度)下植物叶片N、P化学计量特征.结果表明: 湘西南石漠化地区常见植物叶片平均N含量为12.89 g·kg-1,P含量为1.19 g·kg-1,N/P值为11.24,大部分植物生长受到N的限制.不同生活型之间植物叶片N含量为落叶灌木>常绿灌木>一年生草本>多年生草本,P含量与N/P值为落叶灌木>多年生草本.不同科植物之间叶片N、P含量和N/P值差异显著,禾本科植物叶片N、P含量最低,与其他科植物共同受N限制;豆科植物叶片N含量和N/P值最高,主要受P限制.双子叶植物与C3植物叶片N、P含量分别高于单子叶植物与C4植物,N/P值差异均不显著.固氮植物叶片N含量以及N/P值均高于非固氮植物,P含量差异不显著.各样地中植物叶片N、P含量之间的相关性显著,N/P值与N含量的相关性显著,仅与中度石漠化样地P含量差异显著.不同石漠化程度之间植物叶N、P含量以及N/P值差异不显著. 相似文献
5.
木兰科植物是常用的园林绿化观赏树种, 研究其叶片碳(C)氮(N)磷(P)计量比和N、P养分重吸收特征, 对于理解和预测树木在人工林中生态功能的发挥至关重要。该研究以木兰科6个树种为研究对象, 于2019年7月和2019年11月至翌年1月分别采集成熟叶和新鲜凋落叶, 测定叶片中C、N、P含量及其计量比, 并分析了6个树种的N、P重吸收特征。结果表明: 成熟叶(凋落叶)C、N和P含量在各树种间存在差异, 其含量变化范围分别为444.73-498.03(389.25-589.33), 9.97-19.51(4.76-8.41)和1.01-1.95 g·kg-1(0.40-1.86 g·kg-1); C含量在各树种间变化范围较小, N、P含量在树种间变化范围较大, N∶P比值在成熟叶和凋落叶中均小于全国陆地植物叶片平均值14.4, 说明木兰科植物的生长受N限制; 常绿树种和落叶树种间成熟叶C、N含量和C:N存在显著差异(p <0.05), P含量、C∶P和N∶P无明显变化(p >0.05), 凋落叶C、P含量和N∶P存在显著差异, N含量和C∶N、C∶P无明显变化; 成熟叶片中的N∶P比与C、N、P含量及其各计量比间均存在显著或极显著相关, 说明N、P间的耦合作用对C物质的积累和在生态系统中的循环及养分利用效率起着重要作用。对叶片中N、P的重吸收在树种间存在差异, 其中落叶树种对N的重吸收显著高于常绿树种, 对P的重吸收则是常绿树种明显高于落叶树种。研究结果有助于加强对木兰科植物的科学施肥养护管理, 加深其在特定区域生态系统中C、N、P循环的理解。 相似文献
6.
桂西北喀斯特区原生林与次生林鲜叶和凋落叶化学计量特征 总被引:7,自引:0,他引:7
研究喀斯特生态脆弱区植物新鲜叶片与凋落叶的元素化学计量学性状,对该地区森林生态系统的恢复与重建具有重要指导意义。在桂西北喀斯特区分别选取了3个原生林群落与3个次生林群落,研究其建群种植物新鲜叶片和凋落叶的C、N、P元素含量及其生态化学计量特征。结果发现,6个群落建群种新鲜叶片C、N、P含量(其平均含量分别为404.3、22.5、1.75 mg/g)均大于凋落叶(平均含量分别为376.5、19.0、1.35 mg/g),鲜叶C:N、C:P、N:P比值(均值分别为17.8、244.9、13.8)均小于凋落叶(均值分别为19.3、315.3、16.3)。6种植物新鲜叶片N、P含量大于凋落叶,而N:P比小于凋落叶,表明喀斯特区植物对N的再吸收率大于P。3个原生林群落建群种鲜叶与凋落叶的平均C、N含量均大于次生林,而P含量则略小于次生林;原生林鲜叶与凋落叶的C:N比均小于次生林,C:P、N:P则大于次生林,推测次生林相对于原生林有更快的生长速率。原生林鲜叶N:P比为13—15之间,次生林鲜叶N:P比为11—12之间,次生林鲜叶与凋落叶的N:P比均小于原生林,说明原生林凋落物分解相对较慢,原生林能相对多的保留养分以供植物吸收,更能适应喀斯特石生环境。植物鲜叶和凋落叶的C:N与N:P比值均呈极显著正相关,说明叶片养分元素间具有共变的特性;叶片N、P含量呈正相关关系,表明植物N:P比具有相对的稳定性,这是高等陆生植物C-N-P元素计量的普遍规律,体现了植物群落对环境的适应。 相似文献
7.
Leaf C,N, and P concentrations and their stoichiometry in peatland plants of Da Hinggan Ling,China 下载免费PDF全文
《植物生态学报》2018,42(12):1154
叶片碳(C)、氮(N)、磷(P)含量及其化学计量特征为植物养分状况和元素限制性提供依据。为了解不同生活型植物叶片C、N、P化学计量特征的变化,该研究测定、分析了大兴安岭地区18个泥炭地常见的3种草本植物——白毛羊胡子草(Eriophorum vaginatum)、玉簪薹草(Carex globularis)、小叶章(Deyeuxia angustifolia), 5种落叶灌木——柴桦(Betula fruticosa)、越桔柳(Salix myrtilloides)、细叶沼柳(Salix rosmarinifolia)、笃斯越桔(Vaccinium uliginosum)、越桔(Vaccinium vitis-idaea)和3种常绿灌木——杜香(Ledum palustre)、地桂(Chamaedaphne calyculata)、头花杜鹃(Rhododendron capitatum)的叶片C、N、P含量。结果表明: (1)落叶和常绿灌木叶片C、N、P含量总体高于草本植物而C:N、C:P、N:P低于草本植物, 说明不同生活型植物具有不同的养分利用策略,灌木叶片C、N、P储存高于草本植物而N、P利用效率低于草本植物; (2)小叶章和头花杜鹃叶片N:P小于10, 同时其N含量小于全球植物叶片平均N含量, 相比其他植物来说更易受N限制; (3)采样地点解释了叶片C、N、P指标变异的12.8%-40.8%, 植物种类对叶片C、N、P指标变异的解释量占9.3%-25.5%; (4)草本植物C、N、P指标的地点间变异系数高于落叶和常绿灌木, 草本植物C、N、P指标对地点因素变化的响应较灌木敏感; (5)草本植物N含量种间变异系数高于落叶和常绿灌木, 落叶灌木P含量种间变异系数高于草本植物和常绿灌木, 草本植物和落叶灌木N、P吸收的种间生理分化较常绿灌木高。 相似文献
8.
养分再吸收是植物养分利用的重要策略,体现了植物对养分留存、利用和适应环境的能力。为研究亚热带不同生活型(常绿与落叶)阔叶树养分含量与养分再吸收的关系,以江西阳际峰国家级自然保护区内30种阔叶树为研究对象,测定成熟和衰老叶片氮(N)和磷(P)含量,分析常绿和落叶树种叶片N和P含量及其再吸收效率差异,揭示阔叶树种叶片养分再吸收效率对植物生活型的响应。结果表明: 落叶树种成熟叶片N和P含量显著高于常绿树种,衰老叶片P含量显著高于常绿树种,而两者衰老叶N含量差异不显著;30种阔叶林木叶片的氮再吸收效率(NRE)与磷再吸收效率(PRE)平均值分别为49.6%和50.9%,两种生活型树种间叶片的NRE与PRE无显著差异;落叶和常绿树种叶片的NRE均与衰老叶N含量呈显著负相关,PRE则与衰老叶P含量呈显著负相关,且这种关系在不同生活型之间差异不显著;总物种的PRE-NRE异速生长指数为1.18。江西阳际峰30种不同生活型阔叶树的养分再吸收效率会影响衰老叶片的养分状况,且相较于N,植物偏好从衰老叶中再吸收P。 相似文献
9.
《植物生态学报》2018,(12)
叶片碳(C)、氮(N)、磷(P)含量及其化学计量特征为植物养分状况和元素限制性提供依据。为了解不同生活型植物叶片C、N、P化学计量特征的变化,该研究测定、分析了大兴安岭地区18个泥炭地常见的3种草本植物——白毛羊胡子草(Eriophorum vaginatum)、玉簪薹草(Carex globularis)、小叶章(Deyeuxia angustifolia), 5种落叶灌木——柴桦(Betula fruticosa)、越桔柳(Salix myrtilloides)、细叶沼柳(Salix rosmarinifolia)、笃斯越桔(Vaccinium uliginosum)、越桔(Vaccinium vitis-idaea)和3种常绿灌木——杜香(Ledum palustre)、地桂(Chamaedaphne calyculata)、头花杜鹃(Rhododendron capitatum)的叶片C、N、P含量。结果表明:(1)落叶和常绿灌木叶片C、N、P含量总体高于草本植物而C:N、C:P、N:P低于草本植物,说明不同生活型植物具有不同的养分利用策略,灌木叶片C、N、P储存高于草本植物而N、P利用效率低于草本植物;(2)小叶章和头花杜鹃叶片N:P小于10,同时其N含量小于全球植物叶片平均N含量,相比其他植物来说更易受N限制;(3)采样地点解释了叶片C、N、P指标变异的12.8%-40.8%,植物种类对叶片C、N、P指标变异的解释量占9.3%-25.5%;(4)草本植物C、N、P指标的地点间变异系数高于落叶和常绿灌木,草本植物C、N、P指标对地点因素变化的响应较灌木敏感;(5)草本植物N含量种间变异系数高于落叶和常绿灌木,落叶灌木P含量种间变异系数高于草本植物和常绿灌木,草本植物和落叶灌木N、P吸收的种间生理分化较常绿灌木高。 相似文献
10.
《植物生态学报》2015,(7)
探明我国西南喀斯特生态脆弱区植被恢复重建背景下,森林植物、凋落物与土壤碳(C)、氮(N)、磷(P)化学计量特征有助于深入地认识喀斯特森林生态系统养分循环规律和系统稳定机制。该文选取桂西北典型喀斯特地区域3个原生林群落和3个自然恢复28年的次生林群落,研究其"植物-凋落物-土壤"连续体的C、N、P化学计量学特征及其内在关联。结果表明:1)圆果化香树(Platycarya longipes)、伞花木(Eurycorymbus cavaleriei)和青檀(Pteroceltis tatarinowii)以及圆叶乌桕(Sapium rotundifolium)、八角枫(Alangium chinense)和黄荆(Vitex negundo)6种植物的C、N、P平均含量分别为427.5、21.2、1.2 mg·g–1;凋落物C、N、P平均含量分别为396.2、12.7、0.9 mg·g–1,而表层土壤(0–10 cm)C、N、P平均含量分别为92.0、6.35和1.5 mg·g–1。2)原生林N再吸收率(平均值为42.7%)高于次生林(平均值为36.5%),P再吸收率(20.4%)显著低于次生林(32.3%)(p0.05);6个森林群落N的再吸收率均大于P的再吸收率。3)不同群落凋落物的C:N值差异不显著,原生林植物的C:N值小于次生林、土壤C:N显著大于次生林;原生林土壤C:P与次生林无显著差异,植物与凋落物C:P小于次生林;原生林凋落物与土壤N:P值小于次生林,植物N:P比平均值均为17.4。4)研究区典型森林群落植物中N和P含量呈显著的正相关关系,植物C:N与N:P、C:P与N:P比值均无明显相关关系;经过对数变换后的土壤C:N与N:P呈显著负相关关系,凋落物的C:P与N:P值呈极显著正相关关系。研究结果可为我国西南典型喀斯特脆弱生态区的生态功能恢复与植被重建提供科学依据。 相似文献
11.
广西猫儿山不同海拔常绿和落叶树种的营养再吸收模式 总被引:1,自引:0,他引:1
土壤养分供给性大小是否影响植物氮和磷再吸收效率仍存在争议。调查了广西猫儿山不同海拔常绿和落叶树种成熟和衰老叶片的氮和磷含量,探讨营养再吸收是否受到叶片习性和海拔的影响。所有树种氮和磷再吸收效率的平均值分别为56.5%和52.1%。常绿树种比落叶树种有显著较高的氮再吸收效率(P0.001)和磷再吸收效率(P0.01),这与前者有较低的衰老叶片氮和磷含量密切相关。随着海拔的上升,氮再吸收效率显著下降(P0.01),磷再吸收效率显著提高(P0.05)。氮再吸收效率与土壤氮:磷比(r=-0.41,P0.05)和成熟叶片氮:磷比(r=-0.37,P0.05)负相关,磷再吸收效率与土壤氮:磷比(r=0.44,P0.05)和成熟叶片氮:磷比(r=0.47,P0.01)正相关,表明了树种对低海拔氮限制的适应逐渐转变为对高海拔磷限制的适应。此外,氮再吸收效率与年均温正相关(r=0.43,P0.05)而磷再吸收效率与年均温负相关(r=-0.45,P0.01),这表明气温也是调节树木营养再吸收格局的重要影响因素。不同海拔树种氮和磷再吸收模式的差异可能是引起广西猫儿山常绿树种沿海拔形成双峰分布的原因之一。 相似文献
12.
Abstract. Nutrient conservation in vegetation affects rates of litter decomposition and soil nutrient availability. Although resorption has been traditionally considered one of the most important plant strategies to conserve nutrients in temperate forests, long leaf life‐span and low nutrient requirements have been postulated as better indicators. We aimed at identifying nutrient conservation strategies within characteristic functional groups of NW Patagonian forests on Andisols. We analysed C‐, N‐, P‐, K‐ and lignin‐concentrations in mature and senescent leaves of ten native woody species within the functional groups: broad‐leaved deciduous species, broad‐leaved evergreens and conifers. We also examined mycorrhizal associations in all species. Nutrient concentration in mature leaves and N‐ resorption were higher in broad‐leaved deciduous species than in the other two functional groups. Conifers had low mature leaf nutrient concentrations, low N‐resorption and high lignin/N ratios in senescent leaves. P‐ and K‐resorptions did not differ among functional groups. Broad‐leaved evergreens exhibited a species‐dependent response. Nitrogen in mature leaves was positively correlated with both N resorption and soil N‐fertility. Despite the high P‐retention capacity of Andisols, N appeared to be the more limiting nutrient, with most species being proficient in resorbing N but not P. The presence of endomycorrhizae in all conifers and the broad‐leaved evergreen Maytenus boaria, ectomycorrhizae in all Nothofagus species (four deciduous, one evergreen), and cluster roots in the broad‐leaved evergreen Lomatia hirsuta, would be possibly explaining why P is less limiting than N in these forests. 相似文献
13.
4种阔叶树种叶中氮和磷的季节动态及其转移 总被引:6,自引:1,他引:5
从叶完全展开到生长季结束 ,对常绿阔叶树种日本米槠 (Castanopsis cuspidata(Thunb.) Schottky)和具柄冬青 (Ilexpedunculosa Miq)及落叶阔叶树种栎 (Quercus serrata Murr.)和栓皮栎 (Quercus variabilis Blume)叶片的 N和 P浓度、含量和养分转移进行了测定 .在生长期中日本米槠新叶的 N浓度在 5月为 36 .6 g/ kg,然后降到 15 .5和 17.5 g/ kg之间 ,其老叶的N浓度波动于 10 .4和 13.1g/ kg的范围内 ,而具柄冬青新叶的 N浓度从 2 7.3下降到 16 .0 g/ kg,接着上升到 18.3g/ kg,其老叶的 N浓度在 12 .0到 15 .5 g/ kg的范围内。栎和栓皮栎的叶 N浓度分别从 2 8.8下降到 18.1g/ kg和从 2 8.5下降到17.5 g/ kg。日本米槠新叶的 N含量从 1.5 4下降到 1.35 g/ m2 ,接着上升到 1.5 0 g/ m2 ,其老叶 N含量从 1.36下降到1.0 0 g/ m2 ,接着上升到 1.2 1g/ m2 ,而具柄冬青新叶的 N含量从 2 .2 5下降到 1.6 0 g/ m2 ,接着上升到 2 .2 0 g/ m2 ,其老叶的 N含量从 2 .13下降到 1.6 5 g/ m2。栎和栓皮栎的叶 N含量分别从 2 .10下降到 1.2 8g/ m2和从 2 .95下降到 2 .13g/ m2。日本米槠新叶的 P浓度由 3.39g/ kg降到 1.12和 1.15 g/ kg之间 ,其老叶的 P浓度变化于 0 .6 6和 0 .88g/ kg的范围内 ,而具柄冬青新叶的 相似文献
14.
于2019年8月研究中亚热带同质园11个树种叶片的比叶面积、氮(N)和磷(P)养分重吸收和化学计量特征,分析其养分利用策略。结果表明: 常绿阔叶树种(香叶、香樟、木荷、米槠、醉香含笑和杜英)和常绿针叶树种(杉木和马尾松)成熟叶和衰老叶的比叶面积、N和P含量普遍低于落叶阔叶树种(枫香、无患子和鹅掌楸),而成熟叶片C∶N和C∶P则表现为常绿阔叶树种和常绿针叶树种高于落叶阔叶树种。除米槠外,同质园其他树种N∶P均小于14。相对于其他树种,基于单位质量与单位面积计算的无患子N和P重吸收率均高于50%,马尾松、杉木和香樟P重吸收率也高于50%,而醉香含笑N和P重吸收率最低,仅为15%~30%。成熟叶比叶面积与N和P含量呈显著正相关,而与C∶N和C∶P呈显著负相关。在同质园中,米槠和香叶等常绿阔叶树种与马尾松等常绿针叶树种属于缓慢投资-收益型树种,其通过降低叶片比叶面积以及N、P含量,减少养分损失,从而实现较高的N、P重吸收程度与利用效率。然而,无患子等落叶阔叶树种属于快速投资-收益型树种,N和P利用效率相对较低。此外,同质园树种多受N限制,却不具有较高的N重吸收率,而唯一受P限制的米槠也不具有高P重吸收率。这些结果深入认识了中亚热带不同类型树种的N和P养分利用特点,可为区域造林实践提供科学依据。 相似文献
15.
Nutrient resorption from senescing leaves is an important mechanism of nutrient conservation in temperate deciduous forests.
Resorption, however, may be curtailed by climatic events that cause rapid leaf death, such as severe drought, which has been
projected to double by the year 2100 in the eastern United States. During a record drought in the southeastern US, we studied
18 common temperate winter-deciduous trees and shrubs to understand how extreme drought affects nutrient resorption of the
macronutrients N, P, K, and Ca. Four species exhibited drought-induced leaf senescence and maintained higher leaf water potentials
than the remaining 14 species (here called drought-evergreen species). This strategy prevented extensive leaf desiccation
during the drought and successfully averted large nutrient losses caused by leaf desiccation. These four drought-deciduous
species were also able to resorb N, P, and K from drought-senesced leaves, whereas drought-evergreen species did not resorb
any nutrients from leaves lost to desiccation during the drought. For Oxydendrum arboreum, the species most severely affected by the drought, our results indicate that trees lost 50% more N and P due to desiccation
than would have been lost from fall senescence alone. For all drought-deciduous species, resorption of N and P in fall-senesced
leaves was highly proficient, whereas resorption was incomplete for drought-evergreen species. The lower seasonal nutrient
losses of drought-deciduous species may give them a competitive advantage over drought-evergreen species in the years following
the drought, thereby impacting species composition in temperate deciduous forests in the future. 相似文献
16.
Leaf nitrogen resorption proficiency of seven shrubs across timberline ecotones in the Sergymla Mountains,Southeast Xizang,China 下载免费PDF全文
《植物生态学报》2014,38(12):1325
Aims Our objectives were to disclose why evergreen shrubs, but not deciduous shrubs, dominate above timberline in humid southeastern Qinghai-Xizang Plateau, and to test if different functional types converge in response to the warming climate from aspect of nitrogen limitation.
Methods Based on investigations of nitrogen concentration in senesced leaves of seven shrubs across timberline ecotones in the Sergymla Mountains, Southeast Xizang, we analyzed differences in leaf mass- and area-based nitrogen resorption proficiency among different functional types (evergreen vs. deciduous), altitudes and aspects at 4 200–4 400 m a.s.l.
Important findings Leaf mass-based nitrogen resorption proficiency was higher in the evergreen shrub Rhododendron aganniphum var. schizopeplum than in deciduous shrubs. However, the leaf area-based N resorption proficiency was relatively higher in deciduous shrubs due to their lower leaf mass per unit area. Although no significant difference in the resorption proficiency was found between altitudes or aspects for the deciduous shrubs of Salix oritrepha and Berberis hemsleyana, leaf mass-based N resorption proficiency was higher at higher altitude for the evergreen shrub Rhododendron aganniphum var. schizopeplum. Decreasing N concentration in senesced leaves, i.e., increasing resorption proficiency, which can improve N use efficiency, is an important strategy for the evergreen shrub to cope with the stressful alpine environment across timberline ecotones. Compared with the deciduous shrubs, N resorption proficiency in the evergreen shrub Rhododendron aganniphum var. schizopeplum is assumed to be more sensitive to future climate warming. 相似文献
17.
Yong-Jiang Zhang Qiu-Yun Yang David W. Lee Guillermo Goldstein Kun-Fang Cao 《Oecologia》2013,173(3):721-730
The relative advantages of being deciduous or evergreen in subtropical forests and the relationship between leaf phenology and nutrient resorption efficiency are not well understood. The most successful deciduous species (Lyonia ovalifolia) in an evergreen-dominated subtropical montane cloud forest in southwest (SW) China maintains red senescing leaves throughout much of the winter. The aim of this study was to investigate whether red senescing leaves of this species were able to assimilate carbon in winter, to infer the importance of maintaining a positive winter carbon balance in subtropical forests, and to test whether an extended leaf life span is associated with enhanced nutrient resorption and yearly carbon gain. The red senescing leaves of L. ovalifolia assimilated considerable carbon during part of the winter, resulting in a higher yearly carbon gain than co-occurring deciduous species. Its leaf N and P resorption efficiency was higher than for co-occurring non-anthocyanic deciduous species that dropped leaves in autumn, supporting the hypothesis that anthocyanin accumulation and/or extended leaf senescence help in nutrient resorption. Substantial winter carbon gain and efficient nutrient resorption may partially explain the success of L. ovalifolia versus that of the other deciduous species in this subtropical forest. The importance of maintaining a positive carbon balance for ecological success in this forest also provides indirect evidence for the dominance of evergreen species in the subtropical forests of SW China. 相似文献
18.
Yaoyi Zhang Xiangyin Ni Jing Yang Siyi Tan Shu Liao Dingyi Wang Kai Yue Fuzhong Wu 《Phyton》2022,91(1):185-196
High rainfall in subtropical regions can leach cation elements from ecosystems, which may limit plant growth. Plants often develop efficient resorption patterns to recycle elements, but there is relatively little available information on this topic. In February 2012, a common garden was established in a subtropical forest by planting dominant trees from the area. Green and senescent leaves were sampled from 11 tree species. The concentrations of potassium (K), calcium (Ca), sodium (Na) and magnesium (Mg) were determined, and the resorption efficiencies were calculated. The results showed significant K, Na and Mg resorption in most of the investigated tree species, while Ca mainly displayed accumulation. Evergreen coniferous and evergreen broad-leaved trees (such as Cunninghamia lanceolata, Pinus massoniana, Cinnamomum camphora, and Michelia macclurei) exhibited relatively higher resorption efficiencies of K (39.0%–87.5%) and Na (18.3%–50.2%) than deciduous broad-leaved trees. Higher Mg resorption efficiencies (>50%) were detected in Liriodendron chinense, C. lanceolata and P. massoniana than in other trees. Overall, evergreen coniferous and evergreen broad-leaved trees could show higher cation resorption than deciduous broad-leaved trees. K and Mg resorption efficiencies and Ca accumulation decrease with increasing nutrient concentrations in green leaves. Our results emphasize that nutrient resorption patterns largely depend on elements and plant functions, which provides new insights into the nutrient use strategies of subtropical plants and a reference for the selection of suitable tree species in this region. 相似文献