Nutrient Characteristics in Relation to Plant Size of a Perennial Grass Under Grazing Exclusion in Degraded Grassland.
Nutrient Characteristics in Relation to Plant Size of a Perennial Grass Under Grazing Exclusion in Degraded Grassland.
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DOI：
10.3389/fpls.2018.00295
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发表时间：
2018
影响因子：
5.6
通讯作者：
Li X
中科院分区：
文献类型：
--
作者：
Liu Z;Baoyin T;Duan J;Yang G;Sun J;Li X
确定营养特性和植物大小之间的联系对于减少理解植物表型可塑性机制的不确定性很重要。虽然放牧对植物形态可塑性的积极影响已经得到了很好的证明，但令人惊讶的是，在长期放牧后营养策略与植物地上部大小的关系却知之甚少。对内蒙古草原优势种羊草的营养特性(养分浓度、分配和化学计量比)与形态可塑性的关系进行了试验研究，研究了放牧时间(0、9、15和35年)对羊草形态可塑性的影响。结果表明，各形态性状的可塑性程度与稳定性呈显著负相关。放牧时间延长9年、15年和35年，植株大小分别增加126.41、164.17和247.47%。植株大小与氮(N)、磷(P)浓度呈负相关，与碳(C)浓度呈正相关。放牧排斥引起的羊草叶片和茎中N、P和C分配的变化中，生物量分配和养分浓度的叶茎比贡献了95%以上。与自由放牧相比，放牧9年后羊草个体的养分浓度(平均为-34.84%)、叶到茎的养分分配(平均为-86.75%)和生态化学计量比(平均为+46.54%)发生了显著的变化，而放牧9年、15年和35年的羊草个体的这些营养特性没有明显的变化趋势。我们的研究结果表明，随着放牧时间的延长，对植物表现的时间效应逐渐减弱，无论是在植物的形态可塑性还是营养特性上。长期禁牧条件下，植株大小与营养性状之间存在显著的负相关。
Identifying the linkages between nutrient properties and plant size is important for reducing uncertainty in understanding the mechanisms of plant phenotypic plasticity. Although the positive effects of grazing exclusion on plant morphological plasticity has been well documented, surprisingly little is known about the relationship of nutrient strategies with plant shoot size after long-term grazing exclusion. We experimentally investigated the impacts of grazing exclusion over time (0, 9, 15, and 35 years) on the relationships of nutrient traits (nutrient concentration, allocation, and stoichiometry) of with morphological plasticity in Leymus chinensis, which is a dominant species in grasslands of Inner Mongolia, China. Our results showed that there was a significantly negative correlation between the degrees of plasticity and stability of various morphological traits. Increases in plant size by 126.41, 164.17, and 247.47% were observed with the increase of grazing exclusion time of 9, 15, and 35 years, respectively. Plant size was negatively correlated with nitrogen (N) and phosphorus (P) concentrations, but was positively correlated with carbon (C) concentration. Biomass partitioning and leaf to stem ratios of nutrient concentrations contributed more than 95% of the changes in N, P, and C allocation in L. chinensis leaves and stems induced by grazing exclusions. Nine years’ grazing exclusion rapidly changed the nutrient concentrations (averaged by -34.84%), leaf to stem nutrient allocations (averaged by -86.75%), and ecological stoichiometry (averaged by +46.54%) compared to free-grazing, whereas there was no significant trend of these nutrient traits across the 9, 15, and 35 years’ grazing exclusion in L. chinensis individuals. Our findings suggest that with the increase of the duration of the grazing exclusion, time effects on plant performances gradually weakened both in plant morphological plasticity and nutrient properties. There is a significant negative effect between plant sizes and nutrient traits under long-term grazing exclusion.
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DOI：
10.1016/j.agee.2017.10.023
发表时间：
2018-02-01
期刊：
Agriculture, ecosystems & environment
影响因子：
--
作者：
Abdalla M;Hastings A;Chadwick DR;Jones DL;Evans CD;Jones MB;Rees RM;Smith P
通讯作者：
Smith P
中国北方草原恢复年代土壤粒径碳氮变化
影响因子：
6.1
作者：
He, Nianpeng;Wu, Ling;Han, Xingguo
通讯作者：
Han, Xingguo
影响因子：
1.7
作者：
Bennett, LT;Judd, TS;Adams, MA
通讯作者：
Adams, MA
影响因子：
2.8
作者：
Deleglise, Claire;Loucougaray, Gregory;Alard, Didier
通讯作者：
Alard, Didier
影响因子：
8.9
作者：
Conant, RT;Paustian, K
通讯作者：
Paustian, K