Biomass allocation patterns of alpine grassland species and functional groups along a precipitation gradient on the Northern Tibetan Plateau

2013 ◽  
Vol 10 (6) ◽  
pp. 1097-1108 ◽  
Author(s):  
Jian-shuang Wu ◽  
Zhen-xi Shen ◽  
Xian-zhou Zhang ◽  
Pei-li Shi
Keyword(s):  
Tibetan Plateau ◽  
Functional Groups ◽  
Biomass Allocation ◽  
Alpine Grassland ◽  
Precipitation Gradient ◽  
Grassland Species ◽  
Northern Tibetan Plateau ◽  
Allocation Patterns

scholarly journals Effects of increased N and P availability on biomass allocation and root carbohydrate reserves differ between N-fixing and non-N-fixing savanna tree seedlings

2017 ◽  
Author(s):  
Varan Varma ◽  
Arockia M Catherin ◽  
Mahesh Sankaran
Keyword(s):  
Functional Groups ◽  
Biomass Allocation ◽  
Nutrient Availability ◽  
Belowground Biomass ◽  
Dry Forest ◽  
Plant Functional Groups ◽  
Tree Seedlings ◽  
P Availability ◽  
Nutrient Deposition ◽  
Allocation Patterns

AbstractIn mixed tree-grass ecosystems, tree recruitment is limited by demographic bottlenecks to seedling establishment arising from inter- and intra-life form competition, and disturbances such as fire. Enhanced nutrient availability resulting from anthropogenic nitrogen (N) and phosphorus (P) deposition can alter the nature of these bottlenecks by changing seedling growth and biomass allocation patterns, and lead to longer-term shifts in tree community composition if different plant functional groups respond differently to increased nutrient availability. However, the extent to which tree functional types characteristic of savannas differ in their responses to increased N and P availability remains unclear. We quantified differences in above- and belowground biomass, and root carbohydrate contents – parameters known to influence the ability of plants to compete, as well as survive and recover from fires – in seedlings of multiple N-fixing and non-N-fixing tree species characteristic of Indian savanna and dry-forest ecosystems to experimental N and P additions. N-fixers in our study were co-limited by N and P availability, while non-N-fixers were N limited. Although both functional groups increased biomass production following fertilisation, non-N-fixers were more responsive and showed greater relative increases in biomass with fertilisation than N-fixers. N-fixers had greater baseline investment in belowground resources and root carbohydrate stocks, and while fertilisation reduced root:shoot ratios in both functional groups, root carbohydrate content only reduced with fertilisation in non-N-fixers. Our results indicate that, even within a given system, plants belonging to different functional groups can be limited by, and respond differentially to, different nutrients, suggesting that long-term consequences of nutrient deposition are likely to vary across savannas contingent on the relative amounts of N and P being deposited in sites.

scholarly journals Temporal Variability of Precipitation and Biomass of Alpine Grasslands on the Northern Tibetan Plateau

2019 ◽  
Vol 11 (3) ◽  
pp. 360 ◽  
Author(s):  
Meng Li ◽  
Jianshuang Wu ◽  
Chunqiao Song ◽  
Yongtao He ◽  
Ben Niu ◽  
...  
Keyword(s):  
Tibetan Plateau ◽  
Temporal Variability ◽  
Alpine Grassland ◽  
Anthropogenic Factors ◽  
Time Interval ◽  
Sensitivity Index ◽  
Alpine Grasslands ◽  
Northern Tibetan Plateau ◽  
Grassland Plants ◽  
Precipitation Events

The timing regimes of precipitation can exert profound impacts on grassland ecosystems. However, it is still unclear how the peak aboveground biomass (AGBpeak) of alpine grasslands responds to the temporal variability of growing season precipitation (GSP) on the northern Tibetan Plateau. Here, the temporal variability of precipitation was defined as the number and intensity of precipitation events as well as the time interval between consecutive precipitation events. We conducted annual field measurements of AGBpeak between 2009 and 2016 at four sites that were representative of alpine meadow, meadow-steppe, alpine steppe, and desert-steppe. Thus, an empirical model was established with the time series of the field-measured AGBpeak and the corresponding enhanced vegetation index (EVI) (R2 = 0.78), which was used to estimate grassland AGBpeak at the regional scale. The relative importance of the three indices of the temporal variability of precipitation, events, intensity, and time interval on grassland AGBpeak was quantified by principal component regression and shown in a red–green–blue (RGB) composition map. The standardized importance values were used to calculate the vegetation sensitivity index to the temporal variability of precipitation (VSIP). Our results showed that the standardized VSIP was larger than 60 for only 15% of alpine grassland pixels and that AGBpeak did not change significantly for more than 60% of alpine grassland pixels over the past decades, which was likely due to the nonsignificant changes in the temporal variability of precipitation in most pixels. However, a U-shaped relationship was found between VSIP and GSP across the four representative grassland types, indicating that the sensitivity of grassland AGBpeak to precipitation was dependent on the types of grassland communities. Moreover, we found that the temporal variability of precipitation explained more of the field-measured AGBpeak variance than did the total amount of precipitation alone at the site scale, which implies that the mechanisms underlying how the temporal variability of precipitation controls the AGBpeak of alpine grasslands should be better understood at the local scale. We hypothesize that alpine grassland plants promptly respond to the temporal variability of precipitation to keep community biomass production more stable over time, but this conclusion should be further tested. Finally, we call for a long-term experimental study that includes multiple natural and anthropogenic factors together, such as warming, nitrogen deposition, and grazing and fencing, to better understand the mechanisms of alpine grassland stability on the Tibetan Plateau.

scholarly journals Changes of Aboveground and Belowground Biomass Allocation in Four Dominant Grassland Species Across a Precipitation Gradient

2021 ◽  
Vol 12 ◽  
Author(s):  
Yongjie Liu ◽  
Mingjie Xu ◽  
Guoe Li ◽  
Mingxia Wang ◽  
Zhenqing Li ◽  
...  
Keyword(s):  
Biomass Allocation ◽  
Aboveground Biomass ◽  
Precipitation Amount ◽  
Belowground Biomass ◽  
Leymus Chinensis ◽  
Total Biomass ◽  
Precipitation Gradient ◽  
Plant Parts ◽  
Artemisia Frigida ◽  
Allocation Patterns

Climate change is predicted to affect plant growth, but also the allocation of biomass to aboveground and belowground plant parts. To date, studies have mostly focused on aboveground biomass, while belowground biomass and allocation patterns have received less attention. We investigated changes in biomass allocation along a controlled gradient of precipitation in an experiment with four plant species (Leymus chinensis, Stipa grandis, Artemisia frigida, and Potentilla acaulis) dominant in Inner Mongolia steppe. Results showed that aboveground biomass, belowground biomass and total biomass all increased with increasing growing season precipitation, as expected in this water-limited ecosystem. Biomass allocation patterns also changed along the precipitation gradient, but significant variation between species was apparent. Specifically, the belowground biomass: aboveground biomass ratio (i.e., B:A ratio) of S. grandis was not impacted by precipitation amount, while B:A ratios of the other three species changed in different ways along the gradient. Some of these differences in allocation strategies may be related to morphological differences, specifically, the presence of rhizomes or stolons, though no consistent patterns emerged. Isometric partitioning, i.e., constant allocation of biomass aboveground and belowground, seemed to occur for one species (S. grandis), but not for the three rhizome or stolon-forming ones. Indeed, for these species, the slope of the allometric regression between log-transformed belowground biomass and log-transformed aboveground biomass significantly differed from 1.0 and B:A ratios changed along the precipitation gradient. As changes in biomass allocation can affect ecosystem functioning and services, our results can be used as a basis for further studies into allocation patterns, especially in a context of environmental change.

scholarly journals Alpine grassland fPAR change over the Northern Tibetan Plateau from 2002 to 2011

2017 ◽  
Vol 8 (2) ◽  
pp. 108-116 ◽  
Author(s):  
Bao-Xiong Chen ◽  
Xian-Zhou Zhang ◽  
Yu-Fang Sun ◽  
Jing-Sheng Wang ◽  
Yong-Tao He
Keyword(s):  
Tibetan Plateau ◽  
Alpine Grassland ◽  
Northern Tibetan Plateau
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