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 Soil Phosphorus Speciation and Availability in Meadows and Forests in Alpine Lake Watersheds With Different Parent Materials

2021 ◽  
Vol 3 ◽  
Author(s):  
Thomas Heron ◽  
Daniel G. Strawn ◽  
Mariana Dobre ◽  
Barbara J. Cade-Menun ◽  
Chinmay Deval ◽  
...  
Keyword(s):  
Forest Soils ◽  
Management Practices ◽  
Lake Tahoe ◽  
Parent Material ◽  
P Availability ◽  
Organic P ◽  
Lake Tahoe Basin ◽  
Parent Materials ◽  
Tahoe Basin ◽  
Total P

In the Lake Tahoe Basin in California and Nevada (USA), managing nutrient export from watersheds into streams and the lake is a significant challenge that needs to be addressed to improve water quality. Leaching and runoff of phosphorus (P) from soils is a major nutrient source to the lake, and P loading potential from different watersheds varies as a function of landscape and ecosystem properties, and how the watershed is managed. In this research, P availability and speciation in forest and meadow soils in the Lake Tahoe Basin were measured at two watersheds with different parent material types. Soils developed on andesitic parent materials had approximately twice as much total P compared to those developed on granitic parent materials. Regardless of parent material, organic P was 79–92% of the total P in the meadow soils, and only 13–47% in the forest soils. Most of the soil organic P consisted of monoester P compounds, but a significant amount, especially in meadow soils, was diester P compounds (up to 30% of total extracted P). Water extractable P (WEP) concentrations were ~10 times greater in the granitic forest soils compared to the andesitic forest soils, which had more poorly crystalline aluminosilicates and iron oxides that retain P and thus restrict WEP export. In the meadow soils, microbial biomass P was approximately seven times greater than the forest soils, which may be an important sink for P leached from upland forests. Results show that ecosystem and parent material are important attributes that control P speciation and availability in the Lake Tahoe Basin, and that organic P compounds are a major component of the soil P and are available for leaching from the soils. These factors can be used to develop accurate predictions of P availability and more precise forest management practices to reduce P export into Lake Tahoe.

scholarly journals Simulation of the long-term carbon and nitrogen dynamics in Dutch forest soils under Scots pine

1998 ◽  
Vol 2 (4) ◽  
pp. 439-449 ◽  
Author(s):  
B.-J. Groenenberg ◽  
W. de Vries ◽  
H. Kros
Keyword(s):  
Organic Matter ◽  
Scots Pine ◽  
Forest Soils ◽  
Mineral Soil ◽  
Root Turnover ◽  
Organic Layer ◽  
Transformation Rate ◽  
Organic Layers ◽  
Pine Stands ◽  
Scots Pine Stands

Abstract. Dynamics of C and N in forest soils in the Nutrient Cycling and Soil Acidification Model (NUCSAM) are described by the transformation and decomposition of three organic matter compartments, litter, fermented material and humic material. These three compartments are allocated to the morphological distinguishable L, F and H horizons of the organic layer. Changes in the pools of these organic compartments are described with first order equations for decomposition and transformation. Rate constants for decomposition and transformation were derived by calibrating the model to measured organic matter pools in organic layers of a chrono-sequence of five first succession Scots pine stands between 15 and 120 years old. Simulated pools of organic matter in the organic layers were in agreement with measured pools in the five pine stands, except for the first thirty years of the H-horizon. During this period, an increase in organic matter in the H horizon was simulated while no H horizons were observed in the field. The simulated total pool of organic matter in the organic layer agreed well with values from a field inventory in 20 other Scots pine stands, but the simulated distribution over the three horizons differed from the field measurements which varied among sites. For the Scots pine stands the model was able to simulate the organic matter accumulation in the top 40-cm of the mineral soil; derived almost completely from fine root turnover. The accumulated pool of nitrogen in the organic layer was in agreement with measured pools for the oldest Scots pine stand but was too high for the younger stands. Especially, the accumulation of N in the F-horizon was too fast, presumably due to an overestimated retention of nitrogen.

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.

Effect of forest harvesting and slash piling on microbial biomass and respiration in Newfoundland boreal forests

2007 ◽  
Vol 87 (4) ◽  
pp. 455-458 ◽  
Author(s):  
Martin T Moroni ◽  
Paul Q Carter ◽  
Dean W Strickland ◽  
Franz Makeschin ◽  
Don-Roger Parkinson ◽  
...  
Keyword(s):  
Microbial Biomass ◽  
Key Words ◽  
Boreal Forests ◽  
Fungal Biomass ◽  
Forest Harvesting ◽  
Organic Layer ◽  
Total Microbial Biomass ◽  
Organic Layers ◽  
Respiration Rates ◽  
Fumigation Extraction

Clearcutting Newfoundland boreal forests significantly reduced organic layer fungal and total microbial biomass in clearcut areas with and without slash cover, compared with forested plots. However, aerobically incubated respiration rates were highest in organic layers from clearcut areas under slash, intermediate under forests, and lowest from clearcut areas without slash. Key words: Carbon, ergosterol, fumigation–extraction, fungal biomass, harvest slash, nitrogen

Wounding of aspen roots promotes suckering

2004 ◽  
Vol 82 (3) ◽  
pp. 310-315 ◽  
Author(s):  
Erin C Fraser ◽  
Victor J Lieffers ◽  
Simon M Landhäusser
Keyword(s):  
Populus Tremuloides ◽  
Growth Rates ◽  
Growing Season ◽  
Organic Layer ◽  
Trembling Aspen ◽  
Layer Depth ◽  
Injury Type ◽  
Organic Layers ◽  
Root Injury ◽  
Root Sucker

In early May, 1-m sections of trembling aspen (Populus tremuloides Michx.) roots in a forest cutblock were carefully exposed and examined for damage. Undamaged roots were subjected to one of three wounding treatments (scrape, sever, or uninjured control) and were then reburied to either the full normal organic layer depth or to one third of the normal depth. Following one growing season, the roots were reexposed and assessed for aspen sucker numbers and growth rates. Results indicate that injured roots produced suckers nearly twice as often as uninjured roots. Further, injured roots produced more suckers per root, and these suckers were taller and had greater leaf area. Roots buried under shallow organic layers also generated more suckers, regardless of injury type. The side of injury (distal or proximal) did not affect any of the measured variables. The present study suggests that moderate wounding of aspen roots increases initial sucker numbers and growth rates.Key words: trembling aspen, root sucker, root injury, regeneration.

Decreases in soil P availability are associated with soil organic P declines following forest conversion in subtropical China

CATENA ◽  
2021 ◽  
Vol 205 ◽  
pp. 105459
Author(s):  
Liuming Yang ◽  
Zhijie Yang ◽  
Xiaojian Zhong ◽  
Chao Xu ◽  
Yanyu Lin ◽  
...  
Keyword(s):  
Forest Conversion ◽  
P Availability ◽  
Organic P ◽  
Subtropical China ◽  
Soil P ◽  
Soil P Availability

scholarly journals Nitrogen addition decreases methane uptake caused by methanotroph and methanogen imbalances in a Moso bamboo forest

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Quan Li ◽  
Changhui Peng ◽  
Junbo Zhang ◽  
Yongfu Li ◽  
Xinzhang Song
Keyword(s):  
Community Structure ◽  
Forest Soils ◽  
Nitrogen Addition ◽  
N Deposition ◽  
Moso Bamboo ◽  
Bamboo Forest ◽  
N Addition ◽  
Atmospheric Methane ◽  
Key Factor ◽  
Moso Bamboo Forest

AbstractForest soils play an important role in controlling global warming by reducing atmospheric methane (CH4) concentrations. However, little attention has been paid to how nitrogen (N) deposition may alter microorganism communities that are related to the CH4 cycle or CH4 oxidation in subtropical forest soils. We investigated the effects of N addition (0, 30, 60, or 90 kg N ha−1 yr−1) on soil CH4 flux and methanotroph and methanogen abundance, diversity, and community structure in a Moso bamboo (Phyllostachys edulis) forest in subtropical China. N addition significantly increased methanogen abundance but reduced both methanotroph and methanogen diversity. Methanotroph and methanogen community structures under the N deposition treatments were significantly different from those of the control. In N deposition treatments, the relative abundance of Methanoculleus was significantly lower than that in the control. Soil pH was the key factor regulating the changes in methanotroph and methanogen diversity and community structure. The CH4 emission rate increased with N addition and was negatively correlated with both methanotroph and methanogen diversity but positively correlated with methanogen abundance. Overall, our results suggested that N deposition can suppress CH4 uptake by altering methanotroph and methanogen abundance, diversity, and community structure in subtropical Moso bamboo forest soils.

Measuring unsaturated hydraulic conductivity (K(ψm)) of the F and H soil organic layers at small matric potential (ψm)

2011 ◽  
Vol 91 (6) ◽  
pp. 965-968
Author(s):  
B. Wilske ◽  
E. A. Johnson
Keyword(s):  
Hydraulic Conductivity ◽  
Large Data ◽  
Cold Climate ◽  
Organic Layer ◽  
Matric Potential ◽  
Large Variability ◽  
Organic Layers ◽  
Soil Organic Layer ◽  
Unsaturated Hydraulic Conductivity ◽  
Constant Head

Wilske, B. and Johnson, E. A. 2011. Measuring unsaturated hydraulic conductivity (K(ψm)) of the F and H soil organic layers at small matric potential (ψm). Can. J. Soil Sci. 91: 965–968. K(ψm) of the soil organic layers is a key parameter to assess water redistribution in cold-climate forests. This study tested the twin suction disc apparatus (TSD) as a new method to measure K(ψm) of the F and H layers directly. We compared the results to two studies. One represents a large data base, the other used similar sample locations; but both derived K(ψm) from combining two methods, i.e., pressure plate measurements combined with the instantaneous profile technique or the constant head approach. The TSD data are consistent with previous results considering the large variability in K(ψm) from the combined methods. This suggests that the TSD method represents an alternative to determine K(ψm) of the soil organic layer.

Metal–organic layer derived metal hydroxide nanosheets for highly efficient oxygen evolution

2019 ◽  
Vol 55 (38) ◽  
pp. 5467-5470 ◽  
Author(s):  
Wen-Da Zhang ◽  
Xiaodong Yan ◽  
Tao Li ◽  
Yong Liu ◽  
Qiu-Ting Fu ◽  
...  
Keyword(s):  
Oxygen Evolution ◽  
Metal Hydroxide ◽  
Organic Layer ◽  
Organic Layers ◽  
Highly Efficient ◽  
Metal Organic ◽  
Better Than

Ultrathin metal hydroxide nanosheets derived from metal–organic layers serving as electrocatalysts displayed highly efficient oxygen evolution even better than commercial IrO2.

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