scholarly journals A New Wetness Index to Evaluate the Soil Water Availability Influence on Gross Primary Production of European Forests

Climate ◽  
2019 ◽  
Vol 7 (3) ◽  
pp. 42 ◽  
Author(s):  
Chiara Proietti ◽  
Alessandro Anav ◽  
Marcello Vitale ◽  
Silvano Fares ◽  
Maria Francesca Fornasier ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Primary Production ◽  
Soil Water ◽  
Water Availability ◽  
Tree Species ◽  
Gross Primary Production ◽  
Soil Water Availability ◽  
Arid Environments ◽  
Site Location ◽  
Wetness Index

Rising temperature, drought and more-frequent extreme climatic events have been predicted for the next decades in many regions around the globe. In this framework, soil water availability plays a pivotal role in affecting vegetation productivity, especially in arid or semi-arid environments. However, direct measurements of soil moisture are scarce, and modeling estimations are still subject to biases. Further investigation on the effect of soil moisture on plant productivity is required. This study aims at analyzing spatio-temporal variations of a modified temperature vegetation wetness index (mTVWI), a proxy of soil moisture, and evaluating its effect on gross primary production (GPP) in forests. The study was carried out in Europe on 19 representative tree species during the 2000–2010 time period. Results outline a north–south gradient of mTVWI with minimum values (low soil water availability) in Southern Europe and maximum values (high soil water availability) in Northeastern Europe. A low soil water availability negatively affected GPP from 20 to 80%, as a function of site location, tree species, and weather conditions. Such a wetness index improves our understanding of water stress impacts, which is crucial for predicting the response of forest carbon cycling to drought and aridity.

scholarly journals EFFECT OF WATER AVAILABILITY ON SOIL MICROBIAL BIOMASS IN SECONDARY FOREST IN EASTERN AMAZONIA

2015 ◽  
Vol 39 (2) ◽  
pp. 377-384 ◽  
Author(s):  
Lívia Gabrig Turbay Rangel-Vasconcelos ◽  
Daniel Jacob Zarin ◽  
Francisco de Assis Oliveira ◽  
Steel Silva Vasconcelos ◽  
Cláudio José Reis de Carvalho ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Microbial Biomass ◽  
Soil Water ◽  
Water Availability ◽  
Soil Microbial Biomass ◽  
Secondary Forest ◽  
Microbial Biomass Carbon ◽  
Basal Respiration ◽  
Soil Water Availability ◽  
Soil Microbial

Soil microbial biomass (SMB) plays an important role in nutrient cycling in agroecosystems, and is limited by several factors, such as soil water availability. This study assessed the effects of soil water availability on microbial biomass and its variation over time in the Latossolo Amarelo concrecionário of a secondary forest in eastern Amazonia. The fumigation-extraction method was used to estimate the soil microbial biomass carbon and nitrogen content (SMBC and SMBN). An adaptation of the fumigation-incubation method was used to determine basal respiration (CO2-SMB). The metabolic quotient (qCO2) and ratio of microbial carbon:organic carbon (CMIC:CORG) were calculated based on those results. Soil moisture was generally significantly lower during the dry season and in the control plots. Irrigation raised soil moisture to levels close to those observed during the rainy season, but had no significant effect on SMB. The variables did not vary on a seasonal basis, except for the microbial C/N ratio that suggested the occurrence of seasonal shifts in the structure of the microbial community.

Disentangling the relative contributions of atmospheric demand for water and soil water availability on the stomatal limitation of photosynthesis

2020 ◽  
Author(s):  
Aliénor Lavergne ◽  
Heather Graven ◽  
Iain Colin Prentice
Keyword(s):  
Soil Moisture ◽  
Soil Water ◽  
Water Availability ◽  
Optimality Theory ◽  
Stable Carbon Isotopes ◽  
Environmental Changes ◽  
Vapour Pressure Deficit ◽  
Soil Water Availability ◽  
Evaporative Demand ◽  
Spatial And Temporal Scales

<p>Plants open and close their stomata in response to changes in the environment, so they can absorb the CO<sub>2</sub> they need to grow, while also avoid drying out. Since the activities of leaf stomata determine the exchanges of carbon and water between the vegetation and the atmosphere, it is crucial to incorporate their responses to environmental pressure into the vegetation models predicting carbon and water fluxes on broad spatial and temporal scales. The least-cost optimality theory proposes a simple way to predict leaf behaviour, in particular changes in the ratio of leaf internal (<em>c</em><sub>i</sub>) to ambient (<em>c</em><sub>a</sub>) partial pressure of CO<sub>2</sub>, from four environmental variables, i.e. <em>c</em><sub>a</sub>, growing-season temperature (<em>T</em><sub>g</sub>), atmospheric vapour pressure deficit (<em>D</em><sub>g</sub>), and atmospheric pressure (as indexed by elevation, <em>z</em>). However, even though the theory considers the effect of atmospheric demand for water on <em>c</em><sub>i</sub>/<em>c</em><sub>a</sub>, it does not predict how dry soils with reduced soil water availability further influence <em>c</em><sub>i</sub>/<em>c</em><sub>a</sub>. Recent research has shown that independent of the individual effects of <em>T</em><sub>g</sub>, <em>D</em><sub>g</sub>, <em>c</em><sub>a</sub> and <em>z</em> on <em>c</em><sub>i</sub>/<em>c</em><sub>a</sub>, the model tends to underestimate <em>c</em><sub>i</sub>/<em>c</em><sub>a</sub> values at high soil moisture and to overestimate <em>c</em><sub>i</sub>/<em>c</em><sub>a</sub> values at low soil moisture. Here, we will try to disentangle the relative contribution of <em>D</em><sub>g</sub> and soil moisture on changes in <em>c</em><sub>i</sub>/<em>c</em><sub>a</sub> and test a new implementation of soil moisture effect in the framework of the least-cost hypothesis. To achieve this goal, we will use stable carbon isotopes measurements in leaves and in tree rings at sites with different soil water availability and different evaporative demand. We will then incorporate the improved model based on the least-cost hypothesis into the UK vegetation model JULES and investigate leaf stomatal responses to recent environmental changes across regions.</p>

scholarly journals Characterizing Growing Season Length of Subtropical Coniferous Forests with a Phenological Model

Forests ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 95
Author(s):  
Yuan Gong ◽  
Christina L. Staudhammer ◽  
Susanne Wiesner ◽  
Gregory Starr ◽  
Yinlong Zhang
Keyword(s):  
Climate Change ◽  
Soil Water ◽  
Prescribed Fire ◽  
Water Availability ◽  
Longleaf Pine ◽  
Growing Season ◽  
Soil Water Availability ◽  
Future Climate Change ◽  
Short Term ◽  
Phenological Model

Understanding plant phenological change is of great concern in the context of global climate change. Phenological models can aid in understanding and predicting growing season changes and can be parameterized with gross primary production (GPP) estimated using the eddy covariance (EC) technique. This study used nine years of EC-derived GPP data from three mature subtropical longleaf pine forests in the southeastern United States with differing soil water holding capacity in combination with site-specific micrometeorological data to parameterize a photosynthesis-based phenological model. We evaluated how weather conditions and prescribed fire led to variation in the ecosystem phenological processes. The results suggest that soil water availability had an effect on phenology, and greater soil water availability was associated with a longer growing season (LOS). We also observed that prescribed fire, a common forest management activity in the region, had a limited impact on phenological processes. Dormant season fire had no significant effect on phenological processes by site, but we observed differences in the start of the growing season (SOS) between fire and non-fire years. Fire delayed SOS by 10 d ± 5 d (SE), and this effect was greater with higher soil water availability, extending SOS by 18 d on average. Fire was also associated with increased sensitivity of spring phenology to radiation and air temperature. We found that interannual climate change and periodic weather anomalies (flood, short-term drought, and long-term drought), controlled annual ecosystem phenological processes more than prescribed fire. When water availability increased following short-term summer drought, the growing season was extended. With future climate change, subtropical areas of the Southeastern US are expected to experience more frequent short-term droughts, which could shorten the region’s growing season and lead to a reduction in the longleaf pine ecosystem’s carbon sequestration capacity.

Screening optimum population density in response to soil water availability in dryland wheat: From laboratory to field

2021 ◽  
Vol 257 ◽  
pp. 107147
Author(s):  
Sai-Yong Zhu ◽  
Zheng-Guo Cheng ◽  
Tao Tian ◽  
Dong-Shan Gong ◽  
Guang-Chao Lv ◽  
...  
Keyword(s):  
Population Density ◽  
Soil Water ◽  
Water Availability ◽  
Soil Water Availability ◽  
Optimum Population

scholarly journals Ecometabolic mixture design-fingerprints from exploratory multi-block data analysis in Coffea arabica beans from climate changes: elevated carbon dioxide and reduced soil water availability

2021 ◽  
pp. 129716
Author(s):  
Gustavo Galo Marcheafave ◽  
Cláudia Domiciano Tormena ◽  
Amelia Elena Terrile ◽  
Carlos Alberto Rossi Salamanca-Neto ◽  
Elen Romão Sartori ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Data Analysis ◽  
Soil Water ◽  
Water Availability ◽  
Coffea Arabica ◽  
Climate Changes ◽  
Elevated Carbon Dioxide ◽  
Mixture Design ◽  
Soil Water Availability ◽  
Block Data

scholarly journals Sensitivity of stomatal conductance to soil moisture: implications for tropospheric ozone

2017 ◽  
Author(s):  
Alessandro Anav ◽  
Chiara Proietti ◽  
Laurent Menut ◽  
Stefano Carnicelli ◽  
Alessandra De Marco ◽  
...  
Keyword(s):  
Soil Moisture ◽  
Stomatal Conductance ◽  
Soil Water ◽  
Water Uptake ◽  
Atmospheric Chemistry ◽  
Water Availability ◽  
Dry Deposition ◽  
Lower Troposphere ◽  
Lower Atmosphere ◽  
Water Limitation

Abstract. Soil moisture and water stress play a pivotal role in regulating stomatal behaviour of plants; however, in the last decade, the role of water availability was often neglected in atmospheric chemistry modelling studies as well as in integrated risk assessments, despite through stomata plants remove a large amount of atmospheric compounds from the lower troposphere. The main aim of this study is to evaluate the effect of soil water limitation on stomatal conductance and assess the resulting changes in atmospheric chemistry testing various hypotheses of water uptake by plants in the rooting zone; following the main assumption that roots maximize water uptake, i.e. they adsorb water at different soil depths depending on the water availability, we improve the dry deposition scheme within the chemistry transport model CHIMERE. Results highlight how dry deposition significantly declines when soil moisture is used to regulate the stomatal opening, mainly in the semi-arid environments: in particular, over Europe the amount of ozone removed by dry deposition in one year without considering any soil water limitation to stomatal conductance is about 8.5 Tg O3, while using a dynamic layer that ensures plants to maximize the water uptake from soil, we found a reduction of about 10 % in the amount of ozone removed by dry deposition (~ 7.7 Tg O3). Despite dry deposition occurs from top of canopy to ground level, it affects the concentration of gases remaining into the lower atmosphere with a significant impact on ozone concentration (up to 4 ppb) extending from the surface to the upper troposphere (up to 650 hPa). Our results shed light on the importance of improving the parameterizations of processes occurring at plant level (i.e. from the soil to the canopy) as they have significant implications on concentration of gases in the lower troposphere.

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