植物性状是连接植物与环境的桥梁(Reich, 2014; Anderegg et al., 2018), 承载着植物对外界环境长期适应与进化后所表现的重要信息。当外界环境发生变化时, 植物通常会通过自身性状间的权衡关系对资源进行配置、补偿和平衡, 以最大限度地减小环境变化对植物产生的消极影响(Cornelissen et al., 2003a; Reich et al., 2003; She et al., 2017)。在诸多植物性状中, 叶性状能准确表达植物对环境变化的响应, 是反映植物生产和资源利用的关键性状, 也是从个体器官推导到群落的关键性状(何念鹏等, 2018; Li et al., 2022)。
自Wright等(2004)基于全球植物叶片形态结构性状、生理性状及化学性状, 总结出叶性状间普遍存在协同或权衡变化规律, 提出“叶经济谱”概念以来, 不同区域尺度的植物叶性状特征及其权衡关系的研究已成为生态学领域的研究热点(He et al., 2006, 2020; 刘晓娟和马克平, 2015; Jiang et al., 2021)。研究发现, 植物叶性状在不同环境中对资源的分配存在一种“此消彼长”的权衡策略(陈莹婷和许振柱, 2014)。该权衡策略符合资源分配假说(Koricheva, 2002), 即植物将较多资源分配于叶物理结构建成, 必然会减少对其他方面如光合作用、呼吸作用等生长繁殖所需资源的投入。例如, 随海拔升高, 环境温度和土壤水分含量下降, 植物倾向于利用更小的比叶面积(SLA)和更高的叶干物质含量(LDMC)来适应环境变化(Luo et al., 2019)。同样, 植物在不同区域的资源投资策略也存在差异, 如在气候环境更适宜、多样性更丰富的区域, 其叶性状间的协同或权衡关系更紧密, 植物也呈现更高的资源投资回报率(Heberling & Fridley, 2012; Fajardo et al., 2013)。
近年来, 植物叶性状特征及其权衡关系的研究多集中于草地与森林生态系统(Zhang et al., 2018; 何芸雨等, 2019; 代景忠等, 2021)。尽管针对半干旱地区沙生植物开展了植物资源利用效率、能量分配及植物性状等多方面的研究(Bai et al., 2018; 靳川等, 2020; 蒋燕等, 2022)。但关于半干旱地区沙生植物叶性状随环境梯度变化的研究尚不够充分(Derroie et al., 2018; 曲鹏等, 2018), 无法全面掌握沙生植物对环境变化的响应信息。毛乌素沙地作为维持生态稳定的关键屏障, 是我国进行生态恢复的重点区域, 具有干旱、高温、高辐射和高蒸腾等环境特征(Jia et al., 2016)。近年来气候恶化以及极端天气事件频发, 使该区域植物遭受多种环境胁迫(Huang et al., 2017; 靳川等, 2021)。因此, 研究毛乌素沙地沙丘不同固定阶段的沙生植物叶性状变化规律、性状间的相互关系及资源权衡策略对该地区植被保护与恢复具有重要意义。
黑沙蒿(Artemisia ordosica)属半灌木, 菊科蒿属, 是毛乌素沙地的典型沙生植物, 在抵御风蚀和促进沙地恢复、稳定等方面发挥着重要作用(张军红和吴波, 2014; Bai et al., 2018)。本研究选择黑沙蒿叶面积(LA)、SLA、LDMC等5个形态性状, 叶片碳含量(LCC)、氮含量(LNC)、磷含量(LPC)等5个化学性状以及具有代表性的生理性状——最大净光合速率(Amax)进行研究。主要目的在于: (1)厘清黑沙蒿叶性状在沙丘不同固定阶段的变化规律; (2)分析黑沙蒿叶形态性状、生理性状和化学性状间的关系, 探明在沙丘同一固定阶段及不同阶段叶性状间的相关性; (3)探究黑沙蒿叶性状集合在沙丘不同固定阶段是否存在显著差异, 进而探讨黑沙蒿随沙丘逐渐固定, 其资源权衡策略是否发生变化。研究结果可为半干旱地区沙地植被保护与恢复提供理论参考。
1 材料和方法
1.1 研究区概况
研究区位于宁夏盐池毛乌素沙地生态系统国家定位观测研究站(37.07-38.17° N, 106.50°-107.78° E), 该站位于毛乌素沙地南缘, 海拔1 550 m。气候类型属于典型的半干旱大陆性气候, 年平均气温(1954- 2020年) 8.4 ℃, 年降水量293 mm, 主要集中于生长季, 其中6-9月降水量占全年的70%以上。该地区地带性自然植被主要为沙生灌丛。其中, 黑沙蒿分布广泛, 其分布面积占毛乌素沙地总面积的30%以上, 为该地区的典型沙生灌木物种, 在防风固沙和生态系统恢复方面发挥着重要作用。该区域分布的灌木物种还包括北沙柳(Salix psammophila)、塔落岩黄耆(Corethrodendron lignosum var. laeve)等, 优势草本植物包括赖草(Leymus secalinus)、草木樨状黄耆(Astragalus melilotoides)、虫实(Corispermum sp.)、沙生针茅(Stipa caucasica subsp. glareosa)等。
1.2 沙丘不同固定阶段样地设置
沙丘固定类型由植被盖度决定, 其中, 具有典型特征的半固定沙丘(D1)植被盖度在10%-30%之间; 固定沙丘(D2)植被盖度≥30%; 土壤结皮固定沙丘(D3)地表覆盖生物土壤结皮, 植被盖度>45%;草本植物固定沙丘(D4)植被盖度>60% (闫峰和丛日春, 2015)。在毛乌素沙地研究区内进行野外调查的基础上, 根据沙地植被逐渐恢复, 沙丘逐渐固定设置样地。根据植被盖度选择D1、D2、D3以及D4作为沙丘的4个不同固定阶段, 各阶段内各设置3个间隔20 m左右的样地(20 m × 20 m)。每个样地内通过对角线法设置5个5 m × 5 m的样方进行灌木调查; 在各样方中再通过同样的方法设置5个1 m × 1 m的小样方进行草本植物调查。沙丘不同固定阶段样地特征如图1和表1。
图1
图1
毛乌素沙地沙丘不同固定阶段样地特征。A, 半固定沙丘阶段。B, 固定沙丘阶段。C, 土壤结皮固定沙丘阶段。D, 草本植物固定沙丘阶段。
Fig. 1
Characteristics of different dune fixation stages in Mau Us Sandy Land. A, Semi-fixed dune stage. B, Fixed dune stage. C, Fixed dune covered with biological soil crusts. D, Fixed dune with abundant herbaceous plants.
表1 毛乌素沙地沙丘不同固定阶段植被特征和土壤理化性质(平均值±标准误)
Table 1
| 植被特征与土壤指标 Vegetation characteristic and soil indicator | 半固定沙丘 Semi-fixed dune stage | 固定沙丘 Fixed dune stage | 土壤结皮固定沙丘 Fixed dune covered with biological soil crusts | 草本植物固定沙丘 Fixed dune with abundant herbaceous plant |
|---|---|---|---|---|
| 植被覆盖度 Vegetation coverage (%) | 23.29 ± 2.39a | 30.27 ± 2.32a | 46.43 ± 3.19b | 61.80 ± 2.80c |
| 黑沙蒿覆盖度 Coverage of Artemisia ordosica (%) | 11.54 ± 1.24a | 22.11 ± 1.72b | 35.24 ± 1.37c | 38.23 ± 2.84c |
| 土壤有机碳含量 Soil organic carbon content (g·kg-1) | 0.55 ± 0.02a | 2.40 ± 0.23b | 0.94 ± 0.02a | 1.43 ± 0.05a |
| 土壤全氮含量 Soil total nitrogen content (g·kg-1) | 0.22 ± 0.01a | 0.31 ± 0.04b | 0.24 ± 0.01ab | 0.30 ± 0.01ab |
| 土壤全磷含量 Soil total phosphorus content (g·kg-1) | 0.05 ± 0.00a | 0.19 ± 0.02b | 0.07 ± 0.00a | 0.12 ± 0.01a |
| 优势物种 Dominant species | 黑沙蒿、塔落岩黄耆、虫实、草木樨状黄耆、沙蓬 Artemisia ordosica, Corethrodendron lignosum var. leave, Corispermum sp., Astragalus melilotoides, Agriophyllum squarrosum | 黑沙蒿、柠条锦鸡儿、草木樨状黄耆、华北白前、达乌里胡枝子 Artemisia ordosica, Caragana korshinskii, Astragalus melilotoides, Vincetoxicum mongolicum, Lespedeza davurica | 黑沙蒿、塔落岩黄耆、草木樨状黄耆、华北白前、中华草沙蚕 Artemisia ordosica, Corethrodendron lignosum var. leave, Astragalus melilotoides, Vincetoxicum mongolicum, Tripogon chinensis | 黑沙蒿、塔落岩黄耆、赖草、糙隐子草、华北白前 Artemisia ordosica, Corethrodendron lignosum var. leave, Leymus secalinus, Cleistogenes squarrosa, Vincetoxicum mongolicum |
不同小写字母表示不同固定阶段的沙丘间差异显著(p < 0.05)。
Different lowercase letters indicate significant differences at different dune fixation stages (p < 0.05).
1.3 样品采集与测定
样品采集与测定在2021年7-8月进行, 用样方法在沙丘不同固定阶段调查植物种类并记录, 测定各物种株数、高度及盖度等特征。单株植物的冠层投影面积(C)采用公式C = πxy/4 (其中x和y分别为冠幅的长轴和短轴)计算得到, 求和得到不同阶段沙丘的植物盖度(司建华等, 2011)。
在4个沙丘固定阶段的各样地中分别选择5株生长良好, 长势相似, 无病虫害的黑沙蒿植株作为实验植株进行标记并测定光合作用参数, 通过光响应曲线拟合求得Amax (µmol·m-2·s-1)。选择在晴朗无风天气的8:00-11:00使用便携式光合仪(LI-6400XT, LI-COR, Lincoln, USA)进行原位测定: 在选择的实验植株向阳方向分别选取3片长势良好叶片进行光合测定, 测定时选择2 cm × 3 cm LED叶室并提前设定参数, CO2浓度设置为400 µmol·mol-1, 流速设置为500 µmol·s-1。黑沙蒿净光合速率达到最大时的光合有效辐射参考Wu等(2018)的研究以及本研究预实验, 通过设置光合有效辐射强度分别为2 000、1 800、1 500、1 200、1 000、800、600、400、200、100、50和0 µmol·mol-1, 测量在各光合有效辐射下的光合速率并通过光响应曲线估算叶片Amax, 从而确定黑沙蒿在光合有效辐射为1 800 µmol·m-2·s-1时净光合速率达到最大并进行设定。测量时使待测叶片铺满整个叶室并在测量数值小数点后一位达到稳定时进行记录, 每个叶片记录20次读数。
在测量Amax后, 对所选定的黑沙蒿植株, 在4个方位分别采集与生理性状测量相似的4片成熟叶片为样本, 即每个样地采集80个样本, 每个沙丘固定阶段有240个样本。将所采集样品置于自封袋内储藏于便携式冷藏箱中及时带回实验室, 分别测定不同沙丘固定阶段黑沙蒿叶片形态性状与化学性状。将黑沙蒿叶片平铺至方格纸上进行拍照, 用Image J图像处理软件计算LA (cm2); 使用精度为0.01 mm的数显游标卡尺测定叶片样品的上、中、下3个部位叶厚(LT, mm), 测量时尽量避开叶脉的位置测定, 重复3次取平均值; 采用浸泡法测定叶片饱和鲜质量; 叶片用烘箱在75 ℃下烘干至少48 h后测量叶干质量。参照Cornelissen等(2003b)的方法计算黑沙蒿其他叶性状: SLA (cm2·g-1) = LA/叶干质量; LDMC (g·g-1) =叶干质量/叶鲜质量; 叶体积(cm3) = LT × LA; 叶组织密度(LTD, g·cm-3) =叶干质量/叶体积。
参考John (1970)的方法测定叶片化学性状。将所采集叶片样品按样方混合并烘干至恒质量后研磨, 经过100目土壤筛后, 分别采用重铬酸钾容量法测定LCC (mg·g-1), 凯氏定氮法测定LNC (mg·g-1), 使用H2SO4-H2O2-HF消煮后比色法测定LPC (mg·g-1)。叶片碳氮比(C:N) = LCC/LNC; 叶片氮磷比(N:P) = LNC/LPC。
土壤理化性质采用常规方法测定, 在进行植物调查的样方内通过“梅花5点法”采取0-30 cm土壤样品, 按照样方混合后用于土壤有机碳、全氮、全磷含量的测定。采用重铬酸钾容量法测定土壤有机碳含量, 采用凯氏定氮法测定土壤全氮含量, 用NaOH熔融-钼锑抗比色法测定土壤全磷含量(鲍士旦, 2000)。
1.4 数据分析
采用单因素方差分析并结合最小显著性差异 (LSD)法检验黑沙蒿叶性状在沙丘不同固定阶段是否存在显著差异。用变异系数(CV)来表示叶性状对沙丘不同固定阶段的敏感程度, CV =标准差/平均值, CV ≤ 20%时为弱变异, 20% < CV ≤ 50%时为中等变异, CV > 50%时为强变异(秦娟等, 2016)。采用Pearson相关性分析探讨沙丘固定各阶段及综合4个阶段叶性状间的相关关系。采用主成分分析(PCA)对不同阶段黑沙蒿叶性状集合进行综合分析并通过相似性分析(ANOSIM)检验各阶段是否存在显著差异, 进而探究其资源权衡策略。所有数据分析与作图均在R 4.1.1软件中进行。
2 结果
2.1 沙丘不同固定阶段黑沙蒿叶性状的差异
方差分析结果表明, 在沙丘不同固定阶段, 黑沙蒿叶片的形态、生理和化学性状都有不同程度的差异(图2)。黑沙蒿的LA、Amax、LCC、LPC以及N:P在不同阶段差异显著。其中, LA和Amax在D1阶段均显著大于其他3个阶段(图2A、2F)。黑沙蒿LCC则随着沙丘逐渐固定, 呈现先显著升高后略下降的变化趋势(图2G)。LPC在D2和D4阶段显著小于D1和D3阶段, 且在D2阶段最低(图2I)。N:P在D1和D3阶段则显著低于其他2个阶段(图2K)。而SLA、LT、LTD、LDMC、LNC以及C:N在不同阶段均无显著差异(图2B-2E、2H、2J)。从变异系数的角度来比较叶性状对沙丘固定不同阶段响应的敏感度。结果表明, 黑沙蒿的LA、Amax、N:P、LPC和LTD的变异系数大于20%, 属于对沙丘不同固定阶段响应较敏感的中等变异性状; 而其余叶性状的变异系数较小, 为不敏感的惰性性状。
图2
图2
毛乌素沙地沙丘不同固定阶段对黑沙蒿叶性状的影响(平均值±标准误)。Amax, 最大净光合速率; C:N, 叶碳氮比; LA, 叶面积; LCC, 叶碳含量; LDMC, 叶干物质含量; LNC, 叶氮含量; LPC, 叶磷含量; LT, 叶厚; LTD, 叶组织密度; N:P, 叶氮磷比; SLA, 比叶面积。CV, 变异系数。D1, 半固定沙丘阶段; D2, 固定沙丘阶段; D3, 土壤结皮固定沙丘阶段; D4, 草本植物固定沙丘阶段。
Fig. 2
Effects of different dune fixation stages on leaf traits of Artemisia ordosica in Mau Us Sandy Land (mean ± SE). Amax, maximum net photosynthetic rate; C:N, leaf carbon content to nitrogen content ratio; LA, leaf area; LCC, leaf carbon content; LDMC, leaf dry matter content; LNC, leaf nitrogen content; LPC, leaf phosphorus content; LT, leaf thickness; LTD, leaf tissue density; N:P, leaf nitrogen content to phosphorus content ratio; SLA, specific leaf area. CV, coefficient of variation. D1, semi-fixed dune stage; D2, fixed dune stage; D3, fixed dune covered with biological soil crusts; D4, fixed dune with abundant herbaceous plants.
2.2 沙丘不同固定阶段黑沙蒿叶性状间的相互关系
Pearson相关性分析表明, 黑沙蒿叶性状间普遍存在显著或极显著相关关系, 且在沙丘不同固定阶段的叶性状相关关系存在差异(图3)。从沙丘不同固定阶段来看, 黑沙蒿LA与LT在D2、D4阶段的相关性存在显著差异, 两者在D2阶段显著正相关, 在D4阶段则极显著负相关(图3A)。LA与LTD在D1、D2阶段呈显著或极显著负相关关系(图3B), 与LDMC在D4阶段也呈现极显著负相关关系(图3C)。SLA与LTD、LDMC也主要呈现负相关关系。其中, SLA与LTD在D2阶段极显著负相关, 在D3阶段显著负相关(图3E); SLA与LDMC在D2、D3和D4阶段均显著或极显著负相关(图3F)。而D1阶段的LA和Amax之间呈显著正相关关系(图3D)。
图3
图3
毛乌素沙地沙丘不同固定阶段黑沙蒿叶性状间相关关系。Amax, 最大净光合速率; LA, 叶面积; LDMC, 叶干物质含量; LT, 叶厚; LTD, 叶组织密度; SLA, 比叶面积。D1, 半固定沙丘阶段; D2, 固定沙丘阶段; D3, 土壤结皮固定沙丘阶段; D4, 草本植物固定沙丘阶段。
Fig. 3
Relationships between leaf traits of Artemisia ordosica at different dune fixation stages in Mau Us Sandy Land. Amax, maximum net photosynthetic rate; LA, leaf area; LDMC, leaf dry matter content; LT, leaf thickness; LTD, leaf tissue density; SLA, specific leaf area. D1, semi-fixed dune stage; D2, fixed dune stage; D3, fixed dune covered with biological soil crusts; D4, fixed dune with abundant herbaceous plants.
综合4个阶段(表2), LA与LDMC、N:P、LCC呈极显著或显著负相关关系, 与Amax和LPC均呈极显著正相关关系; LTD与SLA、LT均呈极显著负相关关系; LDMC与SLA、Amax、LPC也存在显著负相关关系; Amax与LCC存在极显著负相关关系。
表2 毛乌素沙地综合各沙丘固定阶段黑沙蒿叶性状间Pearson相关系数分析
Table 2
| LA | SLA | LT | LTD | LDMC | Amax | LCC | LNC | LPC | C:N | N:P | |
|---|---|---|---|---|---|---|---|---|---|---|---|
| LA | 1.00 | ||||||||||
| SLA | 0.22 | 1.00 | |||||||||
| LT | -0.10 | -0.15 | 1.00 | ||||||||
| LTD | -0.22 | -0.72*** | -0.54*** | 1.00 | |||||||
| LDMC | -0.66*** | -0.41* | 0.24 | 0.29 | 1.00 | ||||||
| Amax | 0.63*** | -0.16 | -0.02 | 0.08 | -0.35* | 1.00 | |||||
| LCC | -0.36* | 0.13 | 0.07 | -0.17 | 0.16 | -0.49** | 1.00 | ||||
| LNC | -0.11 | 0.13 | -0.16 | 0.01 | -0.15 | -0.07 | 0.19 | 1.00 | |||
| LPC | 0.50*** | 0.22 | -0.10 | -0.19 | -0.41* | 0.17 | 0.01 | 0.28 | 1.00 | ||
| C:N | -0.03 | -0.05 | 0.17 | -0.11 | 0.19 | -0.17 | 0.43** | -0.79*** | -0.17 | 1.00 | |
| N:P | -0.51** | -0.15 | -0.02 | 0.23 | 0.37* | -0.11 | -0.12 | 0.07 | -0.91*** | -0.21 | 1.00 |
Amax, 最大净光合速率; C:N, 叶碳氮比; LA, 叶面积; LCC, 叶碳含量; LDMC, 叶干物质含量; LNC, 叶氮含量; LPC, 叶磷含量; LT, 叶厚; LTD, 叶组织密度; N:P, 叶氮磷比; SLA, 比叶面积。粗体表示相关性显著; *, p < 0.05; **, p < 0.01; ***, p < 0.001。
Amax, maximum net photosynthetic rate; C:N, leaf carbon content to nitrogen content ratio; LA, leaf area; LCC, leaf carbon content; LDMC, leaf dry matter content; LNC, leaf nitrogen content; LPC, leaf phosphorus content; LT, leaf thickness; LTD, leaf tissue density; N:P, leaf nitrogen content to phosphorus content ratio; SLA, specific leaf area. Bold indicates significant correlation; *, p < 0.05; **, p < 0.01; ***, p < 0.001.
2.3 沙丘不同固定阶段黑沙蒿叶性状集合的差异
图4
图4
毛乌素沙地沙丘不同固定阶段黑沙蒿叶性状主成分(PC)分析结果。A, 黑沙蒿主要叶性状载荷。B, 黑沙蒿叶性状对沙丘固定不同阶段的响应。Amax, 最大净光合速率; C:N, 叶碳氮比; LA, 叶面积; LCC, 叶碳含量; LDMC, 叶干物质含量; LNC, 叶氮含量; LPC, 叶磷含量; LT, 叶厚; LTD, 叶组织密度; N:P, 叶氮磷比; SLA, 比叶面积。D1, 半固定沙丘阶段; D2, 固定沙丘阶段; D3, 土壤结皮固定沙丘阶段; D4, 草本植物固定沙丘阶段。
Fig. 4
Results of principle component (PC) analysis of Artemisia ordosica leaf traits in different dune fixation stages in Mau Us Sandy Land. A, Main leaf trait load of Artemisia ordosica. B, Response of Artemisia ordosica to different stages of dune fixation. Amax, maximum net photosynthetic rate; C:N, leaf carbon content to nitrogen content ratio; LA, leaf area; LCC, leaf carbon content; LDMC, leaf dry matter content; LNC, leaf nitrogen content; LPC, leaf phosphorus content; LT, leaf thickness; LTD, leaf tissue density; N:P, leaf nitrogen content to phosphorus content ratio; SLA, specific leaf area. D1, semi-fixed dune stage; D2, fixed dune stage; D3, fixed dune covered with biological soil crusts; D4, fixed dune with abundant herbaceous plants.
表3 毛乌素沙地沙丘黑沙蒿叶性状在主成分分析中的载荷及解释方差
Table 3
| 叶性状 Leaf trait | 主成分1 Principal component 1 | 主成分2 Principal component 2 | 主成分3 Principal component 3 |
|---|---|---|---|
| LA | 0.47 | 0.07 | 0.27 |
| SLA | 0.26 | -0.28 | -0.32 |
| LT | -0.07 | -0.31 | 0.14 |
| LTD | -0.23 | 0.46 | 0.14 |
| LDMC | -0.44 | -0.05 | 0.04 |
| Amax | 0.26 | 0.32 | 0.36 |
| LCC | -0.13 | -0.42 | -0.27 |
| LNC | 0.09 | 0.23 | -0.62 |
| LPC | 0.44 | -0.06 | -0.10 |
| C:N | -0.12 | -0.46 | 0.43 |
| N:P | -0.40 | 0.23 | -0.10 |
| 方差比例 Variance ratio | 29.20% | 20.03% | 17.11% |
| 累计方差比例 Cumulative variance ratio | 29.20% | 49.23% | 66.34% |
Amax, 最大净光合速率; C:N, 叶碳氮比; LA, 叶面积; LCC, 叶碳含量; LDMC, 叶干物质含量; LNC, 叶氮含量; LPC, 叶磷含量; LT, 叶厚; LTD, 叶组织密度; N:P, 叶氮磷比; SLA, 比叶面积。
Amax, maximum net photosynthetic rate; C:N, leaf carbon content to nitrogen content ratio; LA, leaf area; LCC, leaf carbon content; LDMC, leaf dry matter content; LNC, leaf nitrogen content; LPC, leaf phosphorus content; LT, leaf thickness; LTD, leaf tissue density; N:P, leaf nitrogen content to phosphorus content ratio; SLA, specific leaf area.
图5
图5
毛乌素沙地沙丘不同固定阶段黑沙蒿叶性状相似性分析。D1, 半固定沙丘阶段; D2, 固定沙丘阶段; D3, 土壤结皮固定沙丘阶段; D4, 草本植物固定沙丘阶段。
Fig. 5
Analysis of leaf traits similarities of Artemisia ordosica in different dune fixation stages in Mau Us Sandy Land. D1, semi-fixed dune stage; D2, fixed dune stage; D3, fixed dune covered with biological soil crusts; D4, fixed dune with abundant herbaceous plants.
3 讨论
3.1 沙丘不同固定阶段叶片性状差异分析
植物性状的改变是其适应环境变化的重要策略(Ackerly et al., 2002; Cornelissen et al., 2003a)。从黑沙蒿的形态性状和生理性状来看, LA和Amax的响应基本一致, D1阶段的LA和Amax最大, 且均随沙丘逐渐固定呈现显著减小的趋势。而植物叶性状对环境和资源差异的响应也反映了植物生长和竞争能力(He et al., 2006)。本研究中, D1阶段的土壤养分较其余3个阶段更低, 资源条件的限制促使黑沙蒿通过增大LA和光合作用来提高生存能力(Dong et al., 2020)。除LA和Amax外, 植物的LDMC也是表征其适应环境变化的重要性状指标(Zhang et al., 2007)。然而, 在本研究中黑沙蒿LDMC在沙丘不同固定阶段中无显著差异。从叶性状变异系数来看, 黑沙蒿在不同阶段的LDMC变异系数为所测11个叶性状中最小, 属于对沙丘环境变化产生弱变异的叶性状。这也表明部分植物的LDMC对环境变化的响应并不敏感(Ryser et al., 1996; 肖迪等, 2016)。
从化学性状来看, 植物氮磷等化学计量特征与其生长速率密切相关(Elser et al., 1996)。本研究发现, 在沙丘逐渐固定过程中, 黑沙蒿LPC和N:P均发生显著变化。D2阶段LPC显著低于其他3个阶段, 且N:P显著高于其他阶段; 而在D1阶段则具有最高的LPC和最低的N:P。该研究结果符合生长速率假说。即植物具有较高生长速率则需要足够的核糖体和蛋白质, 因此也相应具有较高的LPC和较低的N:P (Sterner & Elser, 2002; Tian et al., 2019)。故随植物生长速率增加, 其N:P一般呈降低趋势, 而LPC呈增加趋势。该结果表明黑沙蒿在植被盖度低, 环境贫瘠的D1阶段具有较高的生长速率。这可能是因为D1阶段的黑沙蒿受环境胁迫, 更倾向于快速生长繁殖, 达到迅速完成其生活史的目的(Li et al., 2011)。
此外, 黑沙蒿SLA、LT、LTD、LNC以及C:P在不同阶段均无显著差异。其中, SLA、LT、LNC与C:P的变异系数均较低, 属于对沙丘不同固定阶段变化不敏感的性状。LTD与LT属于叶片的支撑结构性状, 在叶性状中具有高的连通性和中心性, 对环境变化的响应可能会影响叶片的综合表型, 较难随环境变化而改变(Li et al., 2022)。
3.2 沙丘不同固定阶段叶片性状间相关性分析
植物生长过程中受生理、环境等因素的综合作用, 各性状间呈现一定的相关性(Kerkhoff et al., 2006)。环境变化会影响植物不同叶性状间的协变关系, 进而使其生长生存策略发生调整(Craven et al., 2015)。本研究发现, 在沙丘不同固定阶段, 与植物光合作用相关的LA、SLA (Westoby et al., 2002)与反映物理防御结构的LDMC、LTD间普遍存在显著或极显著负相关关系。本研究结果符合资源分配假说, 即植物将较多资源分配于叶片物理防御结构, 对叶片光合能力的投资则会随物理防御结构投资的增加而降低(Koricheva, 2002)。这也表明植物在生长繁殖和增强防御能力之间存在一种“此消彼长”的权衡关系。本研究中, 不同阶段的黑沙蒿叶性状间相关性存在差异, LA与LTD、SLA与LDMC间的负相关关系均随植被盖度增大和沙丘不断固定更加显著。这是因为植物叶性状间存在很多相互平衡的性状组合, 而这些性状间的相关性并非一成不变, 往往通过自身所得资源的变化调整叶性状的动态变化来适应环境, 以达到生存与繁衍的目的(冯秋红等, 2008; 肖迪等, 2016)。
综合4个阶段来看, 除黑沙蒿叶片形态与生理性状间显著相关外, 两者与化学性状间也存在显著相关关系。表明随着沙丘逐渐固定, 与植物营养相关的叶化学性状与其他叶性状也呈现出紧密相关关系。其中, LA与LCC显著负相关, 与LPC极显著正相关; 而LDMC与LPC显著负相关。一般来说, 植物LPC与其最大潜在生长速率显著正相关(Thompson et al., 1997), 而植物LA与光合速率也存在正相关关系, LA与LPC均能反映植物的生长速率。与植物养分相关的LPC与形态性状LA以及LDMC的相互关系也表明了在毛乌素沙地资源有限条件下, 植物各类叶性状间存在密切相关性, 这种叶性状间的相关性可使植物合理分配和充分利用资源。在本研究中, 沙地植物面临更严峻的资源匮乏挑战, 因此倾向于具有更紧密的叶性状相关性(李颖, 2020)。本研究中黑沙蒿叶片形态、生理和化学性状间普遍存在的相关性表明半干旱地区沙生植物通过叶性状的权衡和协同关系来更充分利用有限资源, 同样也表明植物通过多个性状间相互关系来共同合作完成生存和生产功能(He et al., 2020)。
3.3 沙丘不同固定阶段黑沙蒿的资源权衡策略
植物叶性状能够反映其适应环境变化的资源分配策略(Kattge et al., 2011)。本研究从黑沙蒿叶性状集合随沙丘不同固定阶段的变化来探讨其资源权衡策略。PCA结果表明, 不同阶段的黑沙蒿叶性状集合在第1和第2主成分轴上的排序均发生了变化, 且在不同阶段发生的变化极显著。其中第1主成分轴主要反映LA、LPC、LDMC和N:P等性状, 相当于植物资源权衡策略中的“投资-收益”策略轴。
LA的大小影响着植物光能利用效率, LPC和N:P与生长速率密切相关(田地等, 2021)。一般来说, 具有较高LA、LPC和较低N:P的植物, 通常具有较高的光合速率和生长速率, 并且叶片更薄, 寿命也更短, 而具有更大LDMC和LT的植物则相反(Wright et al., 2001)。在本研究中, D1阶段的黑沙蒿位于第1主成分轴的正向区域, 相较于其他阶段具有较大LA、LPC与Amax, 较小的N:P和LDMC。在D1阶段植被盖度最小, 植物间竞争也较小, 黑沙蒿可充分利用有限资源来加快自身养分循环、提高光合能力和生物量的积累, 即该阶段植物选择生长繁殖高投入策略(Kumar & Garkoti, 2021)。因此, D1阶段的黑沙蒿在资源分配中更倾向于叶片较大较薄、生长速率较高的“快速投资-收益型”策略。
有研究发现, 随着沙丘的固定, 植物的生长和繁殖能力明显下降(Li et al., 2011)。在本研究中, D2阶段的黑沙蒿与D1阶段不同, 其叶性状集合主要位于第1主成分轴的负向区域, 具有较高的LDMC以及较低的LA、SLA和Amax。其中, SLA和LDMC这两个性状常用来反映植物对环境变化的响应策略。一般认为, 植物具有较小的SLA和较大的LDMC有更好的资源获取能力及水分利用效率, 能更好地适应恶劣环境条件(Wilson et al., 1999; 肖迪等, 2016)。SLA的减小与LDMC的增大往往反映了环境条件的恶化, 因为植物开始转变为较为保守的缓慢生长策略(Rose et al., 2013)。而植物在低资源环境中采取构建物理防御、降低养分循环等缓慢生长策略在竞争中更有优势(Funk, 2013; Dong et al., 2020)。在本研究中, 黑沙蒿在D2阶段对LDMC和LTD等植物防御结构的投入高于其他阶段, 而对LA、SLA和Amax等生长相关性状的投入减少。这样的资源分配对于植物抵抗恶劣环境和逐渐增强的植物竞争具有重要意义。因此, D2阶段的黑沙蒿更倾向于叶片较小较厚、防御能力较强、生长速率低的“缓慢投资-收益型”策略。在D3和D4阶段, 沙丘环境条件得到改善, 黑沙蒿在第一主成分轴的正负区域均有分布, 表明这两个阶段的植物在保证正常生长的同时, 也适当增强其防御机制来适应种内和种间竞争。总之, 沙丘不同固定阶段黑沙蒿叶性状集合的显著差异, 以及在快速生长策略与保守策略间的转变是其适应环境变化最直接的方式。
4 结论
在毛乌素沙地沙丘不同固定阶段, 黑沙蒿叶性状的变化表明植物可通过调节叶性状, 对有限的环境资源进行优化配置来提高在不同生境中的适应能力。从叶性状变异系数来看, LA、Amax、N:P、LPC和LTD在沙丘固定不同阶段属于中等变异性状; 而LDMC和LCC等叶性状属于弱变异性状。本研究中黑沙蒿叶性状间普遍存在显著相互关系, 这种性状间的相关性有利于植物充分利用有限资源并通过调整资源分配来适应不同环境。研究还发现黑沙蒿在不同阶段的资源权衡策略存在差异, 在D1阶段黑沙蒿对资源分配更倾向于叶片较大较薄、生长速率较高的“快速投资-收益型”策略; 在D2阶段则更趋向于叶片较小较厚、防御能力较强、生长速率低的“缓慢投资-收益型”策略; 而D3、D4阶段的黑沙蒿在保证正常生长的同时, 也适当增强其防御机制来适应逐渐增强的种内和种间竞争。本研究进一步证实了沙生植物可通过叶性状集合的优化来调整资源利用与权衡策略, 以此提高在不同环境中的生存能力。研究结果可为沙地生态系统植被保护与恢复提供理论基础。
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切根对羊草营养生长期内植物功能性状的影响
DOI:10.17521/cjpe.2021.0230
[本文引用: 1]
该研究以呼伦贝尔羊草(Leymus chinensis)草甸草原割草场为研究对象, 通过对羊草营养生长期内功能性状变化的观测, 研究切根对羊草叶、茎、植株功能性状的影响, 为干扰状态下羊草植株的响应机制和天然割草场植被的恢复提供参考。运用9QP-830型草地破土切根机对草地进行切根处理, 分期测定羊草单株高度、叶长、自然叶宽、展开叶宽、茎粗、茎长、叶质量、茎质量、单株质量等多个功能性状, 通过统计分析切根前后性状的差异, 拟合其变化方程, 探索影响羊草产量的表型性状和质量性状的驱动因子。研究结果显示: (1)切根显著降低了羊草的比叶面积、总叶质量、茎长/茎粗、茎干物质含量, 显著提高了平均叶长和叶面积, 整体上提高了单株质量、株高和植株干物质含量。(2)对照和切根羊草叶、茎功能性状均呈二次曲线变化, 拟合效果达显著或极显著水平。除叶干物质含量、茎干物质含量和茎长/茎粗外, 其余叶、茎功能性状均呈先升高后降低的变化趋势。(3)除叶片数外, 羊草各表型性状之间均呈极显著的正相关关系, 叶质量、茎质量、单株质量之间呈极显著的正相关关系, 比叶面积与质量性状关系不显著。(4)总叶长和总叶质量分别是羊草单株质量表型性状和质量性状之中的最大驱动因子。羊草功能性状间存在协同变化的关系, 切根一定程度上使羊草地上植株的生活史提前。
Contrasting patterns of leaf trait variation among and within species during tropical dry forest succession in Costa Rica
DOI:10.1038/s41598-017-18525-1 [本文引用: 1]
Components of leaf-trait variation along environmental gradients
DOI:10.1111/nph.16558 URL [本文引用: 2]
Organism size, life history, and N:P stoichiometry: toward a unified view of cellular and ecosystem processes
DOI:10.2307/1312897 URL [本文引用: 1]
Similar variation in carbon storage between deciduous and evergreen treeline species across elevational gradients
DOI:10.1093/aob/mct127
PMID:23788748
[本文引用: 1]
The most plausible explanation for treeline formation so far is provided by the growth limitation hypothesis (GLH), which proposes that carbon sinks are more restricted by low temperatures than by carbon sources. Evidence supporting the GLH has been strong in evergreen, but less and weaker in deciduous treeline species. Here a test is made of the GLH in deciduous-evergreen mixed species forests across elevational gradients, with the hypothesis that deciduous treeline species show a different carbon storage trend from that shown by evergreen species across elevations.Tree growth and concentrations of non-structural carbohydrates (NSCs) in foliage, branch sapwood and stem sapwood tissues were measured at four elevations in six deciduous-evergreen treeline ecotones (including treeline) in the southern Andes of Chile (40°S, Nothofagus pumilio and Nothofagus betuloides; 46°S, Nothofagus pumilio and Pinus sylvestris) and in the Swiss Alps (46°N, Larix decidua and Pinus cembra).Tree growth (basal area increment) decreased with elevation for all species. Regardless of foliar habit, NSCs did not deplete across elevations, indicating no shortage of carbon storage in any of the investigated tissues. Rather, NSCs increased significantly with elevation in leaves (P < 0·001) and branch sapwood (P = 0·012) tissues. Deciduous species showed significantly higher NSCs than evergreens for all tissues; on average, the former had 11 % (leaves), 158 % (branch) and 103 % (sapwood) significantly (P < 0·001) higher NSCs than the latter. Finally, deciduous species had higher NSC (particularly starch) increases with elevation than evergreens for stem sapwood, but the opposite was true for leaves and branch sapwood.Considering the observed decrease in tree growth and increase in NSCs with elevation, it is concluded that both deciduous and evergreen treeline species are sink limited when faced with decreasing temperatures. Despite the overall higher requirements of deciduous tree species for carbon storage, no indication was found of carbon limitation in deciduous species in the alpine treeline ecotone.
Response of plant functional traits to environment and its application
植物功能性状对环境的响应及其应用
The physiology of invasive plants in low- resource environments
DOI:10.1093/conphys/cot026 [本文引用: 1]
A test of the generality of leaf trait relationships on the Tibetan Plateau
DOI:10.1111/j.1469-8137.2006.01704.x URL [本文引用: 2]
Plant trait networks: improved resolution of the dimensionality of adaptation
DOI:10.1016/j.tree.2020.06.003 URL [本文引用: 2]
Perspectives and challenges in plant traits: from organs to communities
植物性状研究的机遇与挑战: 从器官到群落
Research progress of trade- off relationships of plant functional traits
DOI:10.17521/cjpe.2019.0122 URL [本文引用: 1]
植物功能性状权衡关系的研究进展
DOI:10.17521/cjpe.2019.0122
[本文引用: 1]
植物功能性状权衡关系反映了植物在资源获取与分配中采取的不同策略, 是近年来生态学研究的一个热点问题。该综述从研究范围、叶性状、器官和植物类群4个方面入手, 简要介绍植物功能性状关系研究在近10余年是如何在叶经济谱(LES)的基础上逐渐扩展和深入的。1)相关研究拓展到全球更多极端环境与特殊气候地区, 发现在不同的气候环境条件下, 植物叶片功能性状关系相对稳定, 植物种内的功能性状关系已被证实与LES相似; 2)功能性状网络从最初的6个经济性状扩展到叶片的分解、燃烧和水力等性状, 发现叶片的分解速率和可燃性均与叶片形态性状、养分含量等显著相关, 但叶片水力性状与经济性状的关系则取决于所研究的物种及生存环境的水分条件; 3)研究对象从植物叶片拓展到了根、茎、花、种子及植株整体, 叶片的比叶质量与茎的木质密度、种子大小相耦合, 但叶片形态性状与根和花的相关性状却无显著相关关系, 证明这些器官可能是独立进化的; 4) LES可以很好地解释特殊维管植物的生存适应策略: 入侵植物具有较高的资源利用效率和更快的相对生长速率, 在LES中处于“低投入-快速回报”的一端; 食虫植物的叶片特化为捕食器官, 光合作用及生长速率相对较低, 居于LES “高投入-缓慢回报”的另一端, 此外, 无论是最古老的种子植物苏铁属(Cycas)植物, 或是蕨类和变水植物(苔藓和地衣), 其功能性状关系都与LES大致相同。该文梳理了功能性状关系研究的进展脉络, 提出了一些建议, 期望为未来植物功能性状关系研究的选题和发展提供一些参考。
Biogeographic constraints on the world-wide leaf economics spectrum
DOI:10.1111/j.1466-8238.2012.00761.x URL [本文引用: 1]
Drylands face potential threat under 2 °C global warming target
DOI:10.1038/nclimate3275 URL [本文引用: 1]
Carbon and water exchange over a temperate semi-arid shrubland during three years of contrasting precipitation and soil moisture patterns
Plant nutrient contents rather than physical traits are coordinated between leaves and roots in a desert shrubland
DOI:10.3389/fpls.2021.734775 [本文引用: 1]
Relative changes and biophysical controls of leaf resource use efficiencies in Artemisia ordosica
油蒿叶片资源利用效率相对变化及其生物与非生物影响因素
Relative changes and regulation of photosynthetic energy partitioning components in Artemisia ordosica during growing season
DOI:10.17521/cjpe.2021.0146 URL [本文引用: 1]
黑沙蒿光合能量分配组分在生长季的相对变化与调控机制
DOI:10.17521/cjpe.2021.0146
[本文引用: 1]
为了探明典型荒漠灌木优势物种黑沙蒿(俗名油蒿, Artemisia ordosica)光合过程能量中分配对环境波动的相对变化及其长期调节机制, 该研究于2018年4-10月在宁夏盐池毛乌素沙地, 同时使用MONITORING-PAM多通道荧光监测仪和LI-6400XT便携式光合测量仪对黑沙蒿叶片的最小荧光产量(F<sub>o</sub>)、最大荧光产量(F<sub>m</sub>)、稳态荧光产量(F<sub>s</sub>)、光下最大荧光产量(F<sub>m</sub>′)、净光合速率(P<sub>n</sub>)、暗呼吸速率(R<sub>d</sub>)、蒸腾速率(E)和叶片气孔导度(g<sub>s</sub>)进行现场测定, 在实验室内计算比叶面积(SLA)、单位面积氮含量(N<sub>area</sub>)、叶绿素含量(C<sub>Chl</sub>)和叶绿素a/b (Chl a/b), 分析黑沙蒿光合过程能量分配中固碳耗能占比(Φ<sub>A</sub>)、光呼吸耗能占比(Φ<sub>PR</sub>)、调节性热耗散耗能占比(Φ<sub>NPQ</sub>)和非调节性热耗散耗能占比(Φ<sub>NO</sub>)与环境参数和叶性状参数之间的关系以及能量分配各组分之间的相对变化。结果表明, 光化学反应组分(Φ<sub>A</sub>、Φ<sub>PR</sub>)和热耗散组分(Φ<sub>NPQ</sub>、Φ<sub>NO</sub>)之间呈负相关竞争关系, 两组分内部呈正相关协同关系, E和Φ<sub>A</sub>、Φ<sub>PR</sub>正相关, 和Φ<sub>NPQ</sub>、Φ<sub>NO</sub>负相关。在低土壤含水量(SWC)和高饱和水汽压差(VPD)环境条件下, 黑沙蒿Φ<sub>A</sub>、Φ<sub>PR</sub>和SLA显著降低, Φ<sub>NPQ</sub>和Φ<sub>NO</sub>显著增加。研究认为, 在长期干旱或高蒸散条件下, 黑沙蒿通过降低SLA等途径避免水分的过度流失, 同时将部分过剩光能由光呼吸代谢途径转移到热耗散组分进行耗散。波动环境下黑沙蒿形态性状的变异和光合过程能量分配的长期调节机制, 反映了其利用形态与生理的协同可塑性对逆境的适应。
Light energy partitioning, photoprotection and influencing factors of photosystem II in an exotic species (Salix psammophila) in Mu Us Sandy Land
毛乌素沙地沙柳光系统II光保护机制和能量分配动态及其影响因子
Colorimetric determination of phosphorus in soil and plant materials with ascorbic acid
DOI:10.1097/00010694-197004000-00002 URL [本文引用: 1]
TRY—A global database of plant traits
Phylogenetic and growth form variation in the scaling of nitrogen and phosphorus in the seed plants
Meta-analysis of sources of variation in fitness costs of plant antiherbivore defenses
DOI:10.1890/0012-9658(2002)083[0176:MAOSOV]2.0.CO;2 URL [本文引用: 2]
Functional traits, growth patterns, and litter dynamics of invasive alien and co-occurring native shrub species of chir pine forest in the central Himalaya, India
DOI:10.1007/s11258-021-01140-6 URL [本文引用: 1]
Habitat-specific demography across dune fixation stages in a semi-arid sandland: understanding the expansion, stabilization and decline of a dominant shrub
Leaf trait network architecture shifts with species-richness and climate across forests at continental scale
DOI:10.1111/ele.14009 URL [本文引用: 2]
Plant functional traits—Concepts, applications and future directions
植物功能性状研究进展
Latitudinal pattern and the driving factors of leaf functional traits in 185 shrub species across Eastern China
DOI:10.1093/jpe/rtx065 URL [本文引用: 1]
Stoichiometric characteristics of soil C, N, P and K in different Pinus massoniana forests
马尾松不同林型土壤C、N、P、K的化学计量特征
Research progress of plant economic spectrum
植物经济谱研究进展
The world-wide “fast-slow” plant economics spectrum: a traits manifesto
DOI:10.1111/1365-2745.12211 URL [本文引用: 1]
The evolution of plant functional variation: traits, spectra, and strategies
Management alters interspecific leaf trait relationships and trait-based species rankings in permanent meadows
DOI:10.1111/j.1654-1103.2012.01455.x URL [本文引用: 1]
The importance of tissue density for growth and life span of leaves and roots: a comparison of five ecologically contrasting grasses
DOI:10.2307/2390506 URL [本文引用: 1]
Plasticity in meristem allocation as an adaptive strategy of a desert shrub under contrasting environments
DOI:10.3389/fpls.2017.01933 [本文引用: 1]
Community structure and species diversity of desert plants in the wind-sand area of Yabulai
阿拉善雅布赖风沙区荒漠植物群落结构和物种多样性研究
A comparative study of leaf nutrient concentrations in a regional herbaceous flora
DOI:10.1046/j.1469-8137.1997.00787.x
PMID:33863101
[本文引用: 1]
Mineral nutrient concentrations were determined in leaves of 83 mostly herbaceous species collected from central England. Most samples were analysed for N, P, K, Ca, Mg, Na, Fe, Al, Mn, Cu and Zn. Concentrations of K, N and P showed similar levels of interspecific variability, with the highest concentrations being 6-9 times the lowest. Mg and (especially) Ca were much more variable, with the highest concentrations being 24 and 49 times the lowest respectively. Only in the case of P concentration was the majority of the variance in the data found at or below the species level. Most of the variance in Ca and Mg concentrations was between monocots and dicots. Concentrations of N and P were strongly positively correlated with each other. Only Ca and Mn were consistently associated with soil pH, positively and negatively respectively. Dicots tended to accumulate more Ca and Mn from high soil concentrations than did monocots. Concentration of P was significantly positively correlated with maximum potential relative growth rate. Plants of woodland and arable habitats contained high concentrations of P, and those of pasture and skeletal habitats contained low concentrations of P. The P: N ratio was higher in plants of arable habitats. Species with P-rich leaves tended to be currently increasing in abundance. The results suggest that plants with nutrient-rich foliage grow quickly, dominate nutrient-rich ecosystems and are generally increasing as a result of the eutrophication and disturbance arising from human exploitation.
Review on characteristics and main hypotheses of plant ecological stoichiometry
DOI:10.17521/cjpe.2020.0331
[本文引用: 1]
Plant ecological stoichiometry, as a branch of ecological stoichiometry, focuses on the study of elemental content, ratios and relationships within and across plant organs, and the underlying biotic and abiotic drivers. In the 19th century, chemists detected the elemental contents in plant organs via laboratory experiments, sprouting the exploration of plant stoichiometric characteristics. Nowadays, ecologists have explored plant ecological stoichiometric characteristics and their responses to global changes and relationships with plant functional traits, using both field investigation and manipulative experiments. These sustained efforts have largely enriched the knowledge and understanding of plant ecological stoichiometry. In this paper, we briefly introduced the history and reviewed the research progresses of plant stoichiometry since the 19th century. Firstly, we proposed the developmental history of plant ecological stoichiometry as three main periods: sprouting, hypothesis foundation, and theoretical construction periods, and introduced some representative works for each period. Secondly, we overviewed plant ecological stoichiometric characteristics across organs, life forms and environmental gradients. The geometric mean values of leaf nitrogen (N) and phosphorus (P) contents and N:P mass ratios in global terrestrial plants are 18.74 mg∙g-1, 1.21 mg∙g-1 and 15.55 (i.e. similar to the Redfield ratio of 16:1), respectively. Leaf N and P contents at either species or community level generally show a decreasing trend with increasing temperature and precipitation, and have large variations among life forms, with higher values in herbaceous than woody plants, and deciduous broad-leaved than evergreen broad-leaved and coniferous woody plants. Compared with leaves, the stoichiometric characteristics of fine roots and other organs in plants remain poorly documented. Thirdly, we reviewed the effects of nutrient addition on plant ecological stoichiometric characteristics. In general, N addition increases soil N availability, then the N content and N:P in plants, thus leading to an increase in plant productivity to some extents. P addition might alleviate the N and P imbalance induced by excessive N inputs, and then increase plant P content. However, long-term nutrient fertilization could perturb the intrinsic stoichiometric characteristics in plants, resulting in the deteriorated nutrient imbalance in tissues and then the subsequent decline in plant productivity. Fourthly, we introduced the main hypotheses of plant ecological stoichiometry. These hypotheses include function-associated hypotheses, environment-associated hypotheses and evolution-associated hypotheses, which delineate the relationships of stoichiometric characteristics with plant growth functions, environmental factors and plant evolutionary history, respectively. Finally, we made an outlook on future research in the area of plant ecological stoichiometry, and highlighted ten potential and important research themes.
植物生态化学计量特征及其主要假说
DOI:10.17521/cjpe.2020.0331
[本文引用: 1]
植物生态化学计量学是生态化学计量学的重要分支, 主要研究植物器官元素含量的计量特征, 以及它们与环境因子、生态系统功能之间的关系。19世纪, 化学家们通过室内实验, 分析了植物器官的元素含量, 开始了对植物化学元素之间关系的探索。如今, 生态学家通过野外采样和控制实验, 探索植物化学元素计量特征的变化规律、对全球变化的响应以及与植物功能属性之间的关系, 促进了植物生态化学计量学的快速发展。该文在概述植物生态化学计量学发展简史的基础上, 综述了19世纪以来该领域的研究进展。首先, 该文将植物生态化学计量学的发展历程概括为思想萌芽期、假说奠基期和理论构建期3个时期, 对各个时期的主要研究进行了简要回顾和梳理。第二, 概述了植物主要器官的化学计量特征, 尤其是陆生植物叶片氮(N)和磷(P)的计量特征。总体上, 全球陆生植物叶片N、P含量和N:P (质量比)的几何平均值分别为18.74 mg∙g<sup>-1</sup>、1.21 mg∙g<sup>-1</sup>和15.55 (与16:1的Redfield比一致); 在物种或群落水平上, 叶片N和P含量一般呈现随温度升高、降水增加而降低的趋势。不同生活型植物叶片N和P计量特征差异明显, 尤其是草本植物叶片N和P含量高于木本植物, 落叶阔叶木本植物叶片N和P含量高于常绿木本植物。与叶片相比, 细根和其他器官化学计量特征研究较少。第三, 总结了养分添加实验对植物化学元素计量特征的影响。总体上, N添加一般会提高土壤N的可利用性, 使植物器官中N含量和N:P升高, 在一定程度上提高植物生产力; P添加可能会缓解过量N输入导致的N-P失衡问题, 提高植物器官P含量。但是, 长期过量施肥会打破植物器官原有的元素间计量关系, 导致元素计量关系失衡和生产力下降。第四, 梳理总结了植物生态化学计量学的重要理论、观点和假说, 主要包括刻画化学计量特征与植物生长功能关系的功能关联假说、刻画化学计量特征与环境因子关系的环境关联假说或理论以及刻画化学计量特征与植物进化历史关系的进化关联假说。最后, 指出了植物生态化学计量学研究中存在的问题, 展望了10个未来需要重点关注的研究方向。
Family-level leaf nitrogen and phosphorus stoichiometry of global terrestrial plants
DOI:10.1007/s11427-019-9584-1
PMID:31290101
[本文引用: 1]
Leaf nitrogen (N) and phosphorus (P) concentrations are critical for photosynthesis, growth, reproduction and other ecological processes of plants. Previous studies on large-scale biogeographic patterns of leaf N and P stoichiometric relationships were mostly conducted using data pooled across taxa, while family/genus-level analyses are rarely reported. Here, we examined global patterns of family-specific leaf N and P stoichiometry using a global data set of 12,716 paired leaf N and P records which includes 204 families, 1,305 genera, and 3,420 species. After determining the minimum size of samples (i.e., 35 records), we analyzed leaf N and P concentrations, N:P ratios and N∼P scaling relationships of plants for 62 families with 11,440 records. The numeric values of leaf N and P stoichiometry varied significantly across families and showed diverse trends along gradients of mean annual temperature (MAT) and mean annual precipitation (MAP). The leaf N and P concentrations and N:P ratios of 62 families ranged from 6.11 to 30.30 mg g, 0.27 to 2.17 mg g, and 10.20 to 35.40, respectively. Approximately 1/3-1/2 of the families (22-35 of 62) showed a decrease in leaf N and P concentrations and N:P ratios with increasing MAT or MAP, while the remainder either did not show a significant trend or presented the opposite pattern. Family-specific leaf N∼P scaling exponents did not converge to a certain empirical value, with a range of 0.307-0.991 for 54 out of 62 families which indicated a significant N∼P scaling relationship. Our results for the first time revealed large variation in the family-level leaf N and P stoichiometry of global terrestrial plants and that the stoichiometric relationships for at least one-third of the families were not consistent with the global trends reported previously. The numeric values of the family-specific leaf N and P stoichiometry documented in the current study provide critical synthetic parameters for biogeographic modeling and for further studies on the physiological and ecological mechanisms underlying the nutrient use strategies of plants from different phylogenetic taxa.
Plant ecological strategies: some leading dimensions of variation between species
DOI:10.1146/annurev.ecolsys.33.010802.150452 URL [本文引用: 1]
Specific leaf area and leaf dry matter content as alternative predictors of plant strategies
DOI:10.1046/j.1469-8137.1999.00427.x URL [本文引用: 1]
Strategy shifts in leaf physiology, structure and nutrient content between species of high-and low-rainfall and high-and low-nutrient habitats
DOI:10.1046/j.0269-8463.2001.00542.x URL [本文引用: 1]
Photosynthetic gas-exchange and PSII photochemical acclimation to drought in a native and non-native xerophytic species
(Artemisia ordosica and Salix psammophila).DOI:10.1016/j.ecolind.2018.06.040 URL [本文引用: 1]
Effects of nitrogen addition on leaf traits of common species in natural Pinus tabuliformis forests in Taiyue Mountain, Shanxi Province, China
DOI:10.17521/cjpe.2015.1043 URL [本文引用: 3]
氮添加对山西太岳山天然油松林主要植物叶片性状的影响
DOI:10.17521/cjpe.2015.1043
[本文引用: 3]
为探讨植物性状对大气氮沉降的响应与适应机制, 该文以中国特有的、在北方温性针叶林中广泛分布的天然油松(Pinus tabuliformis)林为研究对象, 在2009-2013年开展了氮添加对植物叶片性状影响的野外控制试验, 4个氮添加浓度分别为0 kg·hm<sup>-2</sup>·a<sup>-1</sup> (CK)、50 kg·hm<sup>-2</sup>·a<sup>-1</sup> (低氮)、100 kg·hm<sup>-2</sup>·a<sup>-1</sup> (中氮)和150 kg·hm<sup>-2</sup>·a<sup>-1 </sup>(高氮)。试验过程中分别测定了油松、蒙古栎(Quercus mongolica)、茶条槭(Acer ginnala)、毛榛(Corylus mandshurica)、沙梾(Cornus bretschneideri)、绣线菊(Spiraea salicifolia)、金银忍冬(Lonicera maackii)、羊须草(Carex callitrichos)、龙常草(Diarrhena mandshurica)、大火草(Anemone tomentosa)和玉竹(Polygonatum odoratum)等11种主要植物的9种叶片性状, 包括叶厚度(LT)、比叶面积(SLA)、干物质含量(LDMC)、叶氮含量(LNC)、叶磷含量(LPC)等。结果表明: 1)在氮添加影响下, 玉竹等个别物种的LT和SLA、绣线菊等部分物种的叶面积(LA)和LDMC差异显著, 上述所有物种的LNC与大多数物种的叶绿素含量(CC)、LPC显著增加, 油松等9种植物叶片N:P发生显著变化, 不同年龄、不同类型的植物叶片对氮添加的响应不同。2)叶性状之间普遍存在显著相关性, 如SLA与LNC和LPC极显著正相关, LT与LNC和LPC极显著负相关, 且相关性随氮添加强度变化。3) 11种植物的叶片特征空间分布规律与叶经济谱的描述一致, 氮添加使植物在特征空间中的位置向叶片薄、生长快、叶寿命短的“快速投资-收益型”一端发生移动; 在垂直方向上, 阔叶乔木、灌木及草本的位置与针叶乔木的移动方向相反。当环境改变时, 植物会改变生存策略, 调整资源分配, 从而保证物种间相对位置和群落整体结构的稳定性。叶经济谱的形成不依赖于环境的变化, 而是植物一种固有的属性。
Study on classification progress and cataloging system of sandy land in China
中国沙地分类进展及编目体系
Allocation strategies for nitrogen and phosphorus in forest plants
DOI:10.1111/oik.05517 URL [本文引用: 1]
Influences of biological soil crust in Artemisia ordosica community on the precipitation infiltration process
黑沙蒿群落生物结皮对降水入渗过程的影响
DOI:10.7523/jssn.2095-6134.2014.02.011
[本文引用: 1]
使用EC-5土壤水分传感器，监测油蒿群落固定沙地上生物结皮覆盖完好（BSC）和去除生物结皮（NBSC）情况下不同深度土层对不同降水事件的响应及整个雨季的土壤水分特征. 研究结果如下：无论降水量大小，相同深度BSC的响应时间均显著大于NBSC；在同一降水事件中，BSC的初始入渗系数和平均入渗系数均显著低于NBSC；在小降水事件时，这种阻碍作用表现得更为明显. 油蒿的吸收根主要分布在40 cm以上土层中，而生物结皮的发育对小于20 mm的降水事件具有较强的阻碍作用；在研究区降水事件以小于20 mm降水为主的情况下，导致40 cm以内土壤水分恶化，久之将导致固定沙地油蒿群落的衰退；研究区降水格局的改变将对土壤水分及植被演替产生重要影响.
Seasonal variation in photosynthesis in six woody species with different leaf phenology in a valley savanna in southwestern China
DOI:10.1007/s00468-007-0156-9 URL [本文引用: 1]
