scholarly journals Phosphorus Leaching From Naturally Structured Forest Soils Is More Affected by Soil Properties Than by Drying and Rewetting

2021 ◽  
Vol 4 ◽  
Author(s):  
Lukas Gerhard ◽  
Heike Puhlmann ◽  
Margret Vogt ◽  
Jörg Luster
Keyword(s):  
Climate Change ◽  
Soil Properties ◽  
Forest Soils ◽  
Climate Change Scenarios ◽  
P Availability ◽  
Soil Columns ◽  
Inorganic P ◽  
Drying And Rewetting ◽  
Foliar Phosphorus ◽  
P Leaching

Foliar phosphorus (P) concentrations in beech trees are decreasing in Europe, potentially leading to reductions in the trees’ growth and vitality. In the course of climate change, drying and rewetting (DRW) cycles in forest soils are expected to intensify. As a consequence, P leakage from the root zone may increase due to temporarily enhanced organic matter mineralization. We addressed the questions whether sites with different soil properties, including P pools, differ in their susceptibility to DRW-induced P leaching, and whether this is affected by the DRW intensity. A greenhouse experiment was conducted on naturally structured soil columns with beech saplings from three sites representing a gradient of soil P availability. Four DRW cycles were conducted by air-drying and irrigating the soils over 4 hours (fast rewetting) or 48 hours (slow rewetting). Leachates below the soil columns were analyzed for total P, and molybdate reactive P (considered as inorganic P). The difference was considered to represent organically bound P. Boosted regression trees were used to examine the effects of DRW and soil characteristics on P leaching. Contrary to a first hypothesis, that P leaching increases upon rewetting with the intensity of the preceding desiccation phase, intense soil drying (to pF 3.5 to 4.5) did not generally increase P leakage compared to moderate drying (to pF 2 to 3). However, we observed increased inorganic P concentrations and decreased organic P concentrations in leachates after drying to matric potentials above pF 4. Also against our expectations, fast rewetting did not lead to higher leakage of P than slow rewetting. However, the results confirmed our third hypothesis that the site poorest in P, where P recycling is mainly limited to the humus layer and the uppermost mineral soil, lost considerably more P during DRW than the other two sites. The results of our experiment with naturally structured soils imply that intensified drying and rewetting cycles, as predicted by climate-change scenarios, may not per se lead to increased P leaching from forest soils. Soil properties such as soil organic carbon content and texture appear to be more important predictors of P losses.

scholarly journals Leaching of Phosphomonoesterase Activities in Beech Forest Soils: Consequences for Phosphorus Forms and Mobility

2021 ◽  
Vol 4 ◽  
Author(s):  
Jasmin Fetzer ◽  
Sebastian Loeppmann ◽  
Emmanuel Frossard ◽  
Aamir Manzoor ◽  
Dominik Brödlin ◽  
...  
Keyword(s):  
Forest Soils ◽  
Nitrogen Addition ◽  
Organic Layer ◽  
P Availability ◽  
Organic P ◽  
Soil Extracts ◽  
Organic Layers ◽  
Water Extracts ◽  
Soil Solutions ◽  
P Leaching

Phosphomonoesterases play an important role in the soil phosphorus (P) cycle since they hydrolyze P monoester to phosphate. Their activity is generally measured in soil extracts, and thus, it remains uncertain how mobile these enzymes are and to which extent they can be translocated within the soil profile. The presence of phosphomonoesterases in soil solutions potentially affects the share of labile dissolved organic P (DOP), which in turn would affect P leaching. Our study aimed at assessing the production and leaching of phosphomonoesterases from organic layers and topsoil horizons in forest soils and its potential effect on dissolved P forms in leachates obtained from zero-tension lysimeters. We measured phosphomonoesterase activities in leached soil solutions and compared it with those in water extracts from litter, Oe/Oa, and A horizons of two beech forests with a contrasting nitrogen (N) and P availability, subjected to experimental N × P fertilization. In addition, we determined phosphate and DOP. In soil solutions leached from litter, Oe/Oa, and A horizons, phosphomonoesterase activities ranged from 2 to 8 μmol L–1 h–1 during summer, but remained below detection limits in winter. The summer values represent 0.1–1% of the phosphomonoesterase activity in soil extracts, indicating that enzymes can be translocated from organic layers and topsoils to greater soil depths. Activities of phosphomonoesterases obtained by water extracts were greater in the organic layer of the P-poor site, while activities of those in soil solutions were similar at the two sites. Nitrogen addition increased phosphomonoesterase activities in leached soil solutions of the organic layer of the N- and P-poor soil. Using a modeling approach, we estimated that approx. 76% of the initial labile DOP was hydrolyzed to dissolved inorganic P within the first 24 h. Back calculations from measured labile DOP revealed an underestimation of approx. 15% of total dissolved P, or 0.03 mg L–1. The observed leaching of phosphomonoesterases implies that labile organic P could be hydrolyzed in deeper soil horizons and that extended sample storage leads to an underestimation of the contribution of DOP to total dissolved P leaching. This has been neglected in the few field studies measuring DOP leaching.

scholarly journals Combined impact of local climate and soil properties on soil moisture patterns

2017 ◽  
Author(s):  
Thushara Gunda ◽  
Udeni P. Nawagamuwa ◽  
George M. Hornberger
Keyword(s):  
Climate Change ◽  
Soil Moisture ◽  
Soil Properties ◽  
Temporal Variations ◽  
Intermediate Zone ◽  
Water Dynamics ◽  
Climate Change Scenarios ◽  
Local Climate ◽  
Dry Zone ◽  
Wet Zone

Abstract. Soil plays a key role in terrestrial water dynamics by retaining precipitation on land. A water balance approach is used to evaluate spatial and temporal variations in soil moisture in Sri Lanka, a country characterized by high spatial variability as reflected in the recognition of three regions of the country, the wet zone, the intermediate zone, and the dry zone. We show that a combination of local climate and soil properties drive spatial patterns of soil moisture deficits on the island, with soils buffering climate variability in the wet zone and enhancing drought patterns in the dry zone. Changes in historical temporal patterns are most notable for the intermediate zone, a region characterized by consistently variable deficits. Counterfactuals of climate change scenarios indicate temperature will drive increases in deficit likelihoods (up to 20 %) in the future, with greatest impact in the intermediate and dry zones, where more than 80 % of the national rice production is concentrated. Given that temperature projections are less uncertain than other climate change impacts, further evaluation of future water stresses are needed. Coupled with remotely-sensed soil moisture data, the findings from this study have implications for infrastructural planning and seasonal crop water allocations in zones with a degree of variability (i.e., neither consistently wet nor consistently dry). Because soil hydrologic regimes reflect inherent, local vulnerabilities, water management decisions need to incorporate regional variabilities in soil moisture dynamics in assessments of climate change adaptations.

scholarly journals Phosphorus status of soils from contrasting forested ecosystems in Southwestern Siberia: combined effects of plant species and climate

2012 ◽  
Vol 9 (6) ◽  
pp. 6365-6408 ◽  
Author(s):  
D. L. Achat ◽  
M. R. Bakker ◽  
L. Augusto ◽  
D. Derrien ◽  
N. Gallegos ◽  
...  
Keyword(s):  
Climate Change ◽  
C Sequestration ◽  
P Availability ◽  
Inorganic P ◽  
Local Climate ◽  
Phosphate Ions ◽  
Decomposition Processes ◽  
Diffusive Phosphate Ions ◽  
Mineral Soils ◽  
Surface Mineral

Abstract. The Russian boreal forest, which mainly consists of extensive forests in Siberia, is the largest continuous forest region on Earth and represents 70 % of the world's boreal forest. Siberian forest is a tremendous repository of terrestrial organic carbon (C), which may increase owing to climate change, potential increases in ecosystem productivity and hence C sequestration. Phosphorus (P) availability could limit the C sequestration potential, but tree roots may mine the soil deeper to increase access to mineral P. Improved understanding and quantification of the processes controlling P availability in surface and deep soil layers of forest ecosystems are thus required. Relative contributions of organic and inorganic P and, consequently, P availability in forest ecosystems depend on decomposition processes, which could be strongly affected by vegetation composition, temperature, precipitation, and their changes due to a warming climate. The objectives of the present study were to (1) evaluate P status of surface and deep forest soil horizons from two contrasted biomes in Southwestern Siberia (i.e. forest steppe in the West Siberian plain and blackish ("chernevaya" in Russian) taiga in the low Salair mountains) and (2) assess the effects of vegetation (siberian fir stand, common aspen stand and herbs in a forest gap) and local climate on soil P fractions. Results revealed high contents in total P (645–1042 mg kg−1 in the surface mineral soils) and available inorganic P (diffusive phosphate ions in one week = 83–126 mg kg−1). In addition, there was an accumulation of diffusive phosphate ions in the subsoils resulting from differences between soil horizons in total inorganic P and soil properties. Consequently, deeper root systems may mine substantial amounts of available P for the trees and the potential enhanced growth and C sequestration due to climate change should thus a~priori not be P-limited. High proportions of total organic P (47–56 % of total P in the surface mineral soils) show that decomposition processes potentially play a significant role in P availability. Results show that decomposition processes are affected by vegetation (deciduous broadleaved trees, evergreen coniferous, herbs) and local climate (precipitations; snow cover with its isolating effect on soil). Results on the effects of plant species and local climate improved our understanding of the potential effects of climate change on P availability through warming and vegetation redistribution.

Modelling impacts of different climate change scenarios on soil water regime of a Mollisol

2005 ◽  
Vol 33 (1) ◽  
pp. 185-188 ◽  
Author(s):  
Csilla Farkas ◽  
Roger Randriamampianina ◽  
Juraj Majerčak
Keyword(s):  
Climate Change ◽  
Soil Water ◽  
Water Regime ◽  
Climate Change Scenarios ◽  
Soil Water Regime

scholarly journals Tackling G × E × M interactions to close on-farm yield-gaps: creating novel pathways for crop improvement by predicting contributions of genetics and management to crop productivity

2021 ◽  
Author(s):  
Mark Cooper ◽  
Kai P. Voss-Fels ◽  
Carlos D. Messina ◽  
Tom Tang ◽  
Graeme L. Hammer
Keyword(s):  
Climate Change ◽  
Crop Improvement ◽  
Target Population ◽  
Crop Productivity ◽  
Climate Change Scenarios ◽  
Global Food Security ◽  
Genotype By Environment ◽  
Improvement Strategies ◽  
Yield Gaps ◽  
On Farm

Abstract Key message Climate change and Genotype-by-Environment-by-Management interactions together challenge our strategies for crop improvement. Research to advance prediction methods for breeding and agronomy is opening new opportunities to tackle these challenges and overcome on-farm crop productivity yield-gaps through design of responsive crop improvement strategies. Abstract Genotype-by-Environment-by-Management (G × E × M) interactions underpin many aspects of crop productivity. An important question for crop improvement is “How can breeders and agronomists effectively explore the diverse opportunities within the high dimensionality of the complex G × E × M factorial to achieve sustainable improvements in crop productivity?” Whenever G × E × M interactions make important contributions to attainment of crop productivity, we should consider how to design crop improvement strategies that can explore the potential space of G × E × M possibilities, reveal the interesting Genotype–Management (G–M) technology opportunities for the Target Population of Environments (TPE), and enable the practical exploitation of the associated improved levels of crop productivity under on-farm conditions. Climate change adds additional layers of complexity and uncertainty to this challenge, by introducing directional changes in the environmental dimension of the G × E × M factorial. These directional changes have the potential to create further conditional changes in the contributions of the genetic and management dimensions to future crop productivity. Therefore, in the presence of G × E × M interactions and climate change, the challenge for both breeders and agronomists is to co-design new G–M technologies for a non-stationary TPE. Understanding these conditional changes in crop productivity through the relevant sciences for each dimension, Genotype, Environment, and Management, creates opportunities to predict novel G–M technology combinations suitable to achieve sustainable crop productivity and global food security targets for the likely climate change scenarios. Here we consider critical foundations required for any prediction framework that aims to move us from the current unprepared state of describing G × E × M outcomes to a future responsive state equipped to predict the crop productivity consequences of G–M technology combinations for the range of environmental conditions expected for a complex, non-stationary TPE under the influences of climate change.

scholarly journals Mapping current and potential future distributions of the oak tree (Quercus aegilops) in the Kurdistan Region, Iraq

2020 ◽  
Vol 9 (1) ◽  
Author(s):  
Nabaz R. Khwarahm
Keyword(s):  
Climate Change ◽  
Habitat Suitability ◽  
Environmental Variables ◽  
Climate Changes ◽  
Future Climate ◽  
Annual Precipitation ◽  
Future Climate Change ◽  
Climate Change Scenarios ◽  
Kurdistan Region ◽  
Oak Tree

Abstract Background The oak tree (Quercus aegilops) comprises ~ 70% of the oak forests in the Kurdistan Region of Iraq (KRI). Besides its ecological importance as the residence for various endemic and migratory species, Q. aegilops forest also has socio-economic values—for example, as fodder for livestock, building material, medicine, charcoal, and firewood. In the KRI, Q. aegilops has been degrading due to anthropogenic threats (e.g., shifting cultivation, land use/land cover changes, civil war, and inadequate forest management policy) and these threats could increase as climate changes. In the KRI and Iraq as a whole, information on current and potential future geographical distributions of Q. aegilops is minimal or not existent. The objectives of this study were to (i) predict the current and future habitat suitability distributions of the species in relation to environmental variables and future climate change scenarios (Representative Concentration Pathway (RCP) 2.6 2070 and RCP8.5 2070); and (ii) determine the most important environmental variables controlling the distribution of the species in the KRI. The objectives were achieved by using the MaxEnt (maximum entropy) algorithm, available records of Q. aegilops, and environmental variables. Results The model demonstrated that, under the RCP2.6 2070 and RCP8.5 2070 climate change scenarios, the distribution ranges of Q. aegilops would be reduced by 3.6% (1849.7 km2) and 3.16% (1627.1 km2), respectively. By contrast, the species ranges would expand by 1.5% (777.0 km2) and 1.7% (848.0 km2), respectively. The distribution of the species was mainly controlled by annual precipitation. Under future climate change scenarios, the centroid of the distribution would shift toward higher altitudes. Conclusions The results suggest (i) a significant suitable habitat range of the species will be lost in the KRI due to climate change by 2070 and (ii) the preference of the species for cooler areas (high altitude) with high annual precipitation. Conservation actions should focus on the mountainous areas (e.g., by establishment of national parks and protected areas) of the KRI as climate changes. These findings provide useful benchmarking guidance for the future investigation of the ecology of the oak forest, and the categorical current and potential habitat suitability maps can effectively be used to improve biodiversity conservation plans and management actions in the KRI and Iraq as a whole.

Impact assessment of common bean availability in Brazil under climate change scenarios

2021 ◽  
Vol 191 ◽  
pp. 103174
Author(s):  
Luís A.S. Antolin ◽  
Alexandre B. Heinemann ◽  
Fábio R. Marin
Keyword(s):  
Climate Change ◽  
Impact Assessment ◽  
Common Bean ◽  
Climate Change Scenarios
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