Nitrogen Metabolism and Photosynthesis in Leymus chinensis in Response to Long-term Soil Drought

2006 ◽  
Vol 25 (3) ◽  
pp. 252-266 ◽  
Author(s):  
Z. Z. Xu ◽  
G. S. Zhou
Keyword(s):  
Nitrogen Metabolism ◽  
Leymus Chinensis ◽  
Soil Drought

scholarly journals Modelling tropical forest responses to drought and El Niño with a stomatal optimization model based on xylem hydraulics

2018 ◽  
Vol 373 (1760) ◽  
pp. 20170315 ◽  
Author(s):  
Cleiton B. Eller ◽  
Lucy Rowland ◽  
Rafael S. Oliveira ◽  
Paulo R. L. Bittencourt ◽  
Fernanda V. Barros ◽  
...  
Keyword(s):  
Tropical Forest ◽  
El Niño ◽  
Optimization Model ◽  
El Nino ◽  
Soil Drought ◽  
Forest Sites ◽  
Dynamic Global Vegetation Models ◽  
Vegetation Models ◽  
Global Vegetation

The current generation of dynamic global vegetation models (DGVMs) lacks a mechanistic representation of vegetation responses to soil drought, impairing their ability to accurately predict Earth system responses to future climate scenarios and climatic anomalies, such as El Niño events. We propose a simple numerical approach to model plant responses to drought coupling stomatal optimality theory and plant hydraulics that can be used in dynamic global vegetation models (DGVMs). The model is validated against stand-scale forest transpiration ( E ) observations from a long-term soil drought experiment and used to predict the response of three Amazonian forest sites to climatic anomalies during the twentieth century. We show that our stomatal optimization model produces realistic stomatal responses to environmental conditions and can accurately simulate how tropical forest E responds to seasonal, and even long-term soil drought. Our model predicts a stronger cumulative effect of climatic anomalies in Amazon forest sites exposed to soil drought during El Niño years than can be captured by alternative empirical drought representation schemes. The contrasting responses between our model and empirical drought factors highlight the utility of hydraulically-based stomatal optimization models to represent vegetation responses to drought and climatic anomalies in DGVMs. This article is part of a discussion meeting issue ‘The impact of the 2015/2016 El Niño on the terrestrial tropical carbon cycle: patterns, mechanisms and implications’.

scholarly journals De novo transcriptomic profiling of the clonal Leymus chinensis response to long-term overgrazing-induced memory

2018 ◽  
Vol 8 (1) ◽  
Author(s):  
Weibo Ren ◽  
Xiangyang Hou ◽  
Zinian Wu ◽  
Lingqi Kong ◽  
Huiqin Guo ◽  
...  
Keyword(s):  
De Novo ◽  
Leymus Chinensis ◽  
Transcriptomic Profiling

scholarly journals Soil bacterial community and functions directly respond to grazing exclusion in a Leymus chinensis steppe of Inner Mongolia, China

2020 ◽  
Author(s):  
Han-Wen Deng ◽  
Xin-Fu Bai ◽  
Ping Zhu ◽  
Yu-Meng Lu ◽  
Lei Ji ◽  
...  
Keyword(s):  
Bacterial Community ◽  
Inner Mongolia ◽  
Soil Bacterial Community ◽  
Leymus Chinensis ◽  
Absolute Abundance ◽  
Ecological Functions ◽  
Grazing Exclusion ◽  
The Absolute ◽  
Soil Bacterial

Abstract Background Grazing exclusion is a common grassland management strategy for restoring degraded grasslands. Its effectiveness on optimizing plant species community, increasing vegetation diversity and biomass, improving soil fertility, has been widely documented in literatures. However, little is known on the responses of the absolute abundance and the ecological functions of soil bacterial community to long-term grazing exclusion. Result In this study, the absolute abundance, diversity, and ecological functions of soil bacterial community were determined by the high-throughput absolute quantitative sequencing technology on a long-term grazing exclusion (40 years, GE) area and three free grazing areas (FGs) within a Leymus chinensis steppe of Inner Mongolia, China, and analyzed the driving forces leading to the variations in soil bacterial community and functions. Our results showed that there was significantly higher soil bacterial abundance in the GE than the FGs along with corresponding variations in vegetation and soil properties. With the decrease of vegetation aboveground biomass, the absolute abundance of soil bacterial community also decreased. Among the phyla of the soil bacterial communities, the relative abundances of Chloroflexi and Firmicutes phyla were especially lower, and that of Verrucomicrobia phylum was higher in the GE than the FGs; the absolute abundances of Euryarchaeota and Microgenomates phyla were especially higher in the GE than the FGs. Conclusions This study suggested that long-term grazing exclusion significantly increased the absolute abundance, changed soil bacterial composition, and especially enhanced bacterial motility and chemotaxis. In particular, soil organic matter was the important agent to influence and connect vegetation and soil. This work will enrich our understanding of the responses of absolute abundance, diversity, and function of the soil bacterial community to long-term grazing exclusion, and help the evaluation of grassland degradation degree and restoration strategy effectiveness.

scholarly journals Photosynthetic acclimation and sensitivity to short- and long-term environmental changes

2021 ◽  
Author(s):  
Leonie Schönbeck ◽  
Charlotte Grossiord ◽  
Arthur Gessler ◽  
Jonas Gisler ◽  
Katrin Meusburger ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Gas Exchange ◽  
Environmental Changes ◽  
Leaf Gas Exchange ◽  
Soil Drought ◽  
List Type ◽  
Evaporative Demand ◽  
Leaf Level ◽  
Short And Long Term

SummaryThe future climate will be characterized by an increase in frequency and duration of drought and warming that exacerbates atmospheric evaporative demand. How trees acclimate to long-term soil moisture changes and whether these long-term changes alter trees’ sensitivity to short-term (day to months) variations of vapor pressure deficit (VPD) and soil moisture is largely unknown.Leaf gas exchange measurements were performed within a long-term (17 years) irrigation experiment in a Scots pine-dominated forest in one of Switzerland’s driest areas on trees in naturally dry (control), irrigated, and‘irrigation-stop’ (after 11 years of irrigation) conditions.Seventeen years of irrigation increased photosynthesis (A) and stomatal conductance (gs) and reduced the gs sensitivity to increasing VPD but not to soil drying. Following irrigation-stop, gas exchange did not decrease immediately, but after three years, had decreased significantly in irrigation-stop trees. Vcmax and Jmax recovered after five years.These results suggest that long-term release of soil drought reduces the sensitivity to atmospheric evaporative demand and that atmospheric constraints may play an increasingly important role in combination with soil drought. In addition, they suggest that structural adjustments lead to an attenuation of initially strong leaf-level acclimation to strong multiple-year drought.

Ectomycorrhizal communities along a precipitation gradient in Bavaria (Germany)

2021 ◽  
Author(s):  
Karin Pritsch ◽  
Max Roth ◽  
Fabian Weikl
Keyword(s):  
Fungal Communities ◽  
Soil Drought ◽  
Precipitation Gradient ◽  
Climate Conditions ◽  
Temperature And Precipitation ◽  
Precipitation Regimes ◽  
Below Ground ◽  
Ectomycorrhizal Communities ◽  
Compositional Patterns

<p>Altered temperature and precipitation regimes particularly prolonged drought periods when combined with heat strongly affect forests in the last decades. However, neither did all trees die nor even stop growing at all sites. We are interested in the question if below ground interaction with ectomycorrhizal fungi could be partly mediating strong soil drought. For this purpose, we established sampling sites with <em>Fagus sylvatica</em>, <em>Picea abies</em> or <em>Pinus sylvestris</em> along a natural precipitation gradient of 400 km length in Bavaria (Germany). We hypothesized root associated fungal communities to reflect long-term adaptation to local edaphic and climate conditions and that the resulting tree-fungal partnerships have distinct compositional patterns.</p>

Nitrogen metabolism of Aloe vera under long-term diluted seawater irrigation

2006 ◽  
Vol 08 (01) ◽  
pp. 33-36
Author(s):  
Liu ZhaoPu ◽  
Zhao GengMao ◽  
Liu Ling ◽  
Zheng QingSong
Keyword(s):  
Nitrogen Metabolism ◽  
Aloe Vera ◽  
Seawater Irrigation
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