-
Societal challenges in understanding and responding to regime shifts in forest landscapes
-
2 excerpts: "The degradation of seminatural landscapes at regional scales, whereby essential functional capabilities and biotic elements are permanently lost as a result of altered disturbance regimes, is a widespread phenomenon."
and "Salvage logging of burned or windthrown forests not only eliminates critical structural legacies from predisturbance stands but can disrupt natural regenerative processes, as noted below (10, 11)."
Located in
Resources
/
Climate Science Documents
-
Soil food web properties explain ecosystem services across European land use systems
-
Intensive land use reduces the diversity and abundance of many soil biota, with consequences for the processes that they govern and the ecosystem services that these processes underpin. Relationships between soil biota and ecosystem processes have mostly been found in laboratory experiments and rarely are found in the field. Here, we quantified, across four countries of contrasting climatic and soil conditions in Europe, how differences in soil food web composition resulting from land use systems (intensive wheat rotation, extensive rotation, and permanent grassland) influence the functioning of soils and the ecosystem services that they deliver. Intensive wheat rotation consistently reduced the biomass of all components of the soil food web across all countries. Soil food web properties strongly and consistently predicted processes of C and N cycling across land use systems and geographic loca- tions, and they were a better predictor of these processes than land use. Processes of carbon loss increased with soil food web properties that correlated with soil C content, such as earthworm biomass and fungal/bacterial energy channel ratio, and were greatest in permanent grassland. In contrast, processes of N cycling were explained by soil food web properties independent of land use, such as arbuscular mycorrhizal fungi and bacterial channel biomass. Our quantification of the contribution of soil organisms to processes of C and N cycling across land use systems and geographic locations shows that soil biota need to be included in C and N cycling models and highlights the need to map and conserve soil biodiversity across the world.
soil fauna | modeling | soil microbes | nitrogen
Located in
Resources
/
Climate Science Documents
-
Soil for Water
-
Learn more about NCAT’s Soil for Water project, working to capture and hold more water in the soil.
Located in
Training
/
Videos and Webinars
-
Soil Health
-
Located in
Resources
-
Soil Health Institute
-
The Soil Health Institute is a non-profit whose mission is to safeguard and enhance the vitality and productivity of soil through scientific research and advancement. The Institute works with its many stakeholders to identify gaps in research and adoption; develop strategies, networks and funding to address those gaps; and ensure beneficial impact of those investments to agriculture, the environment and society.
Located in
LP Members
/
Organizations Search
-
Soil Health Videos and Webinars
-
Located in
Training
/
Videos and Webinars
-
Soil organic matter turnover is governed by accessibility not recalcitrance
-
Mechanisms to mitigate global climate change by sequestering carbon (C) in different ‘sinks’ have been proposed as at least temporary measures. Of the major global C pools, terrestrial ecosystems hold the potential to capture and store substantially increased volumes of C in soil organic matter (SOM) through changes in management that are also of benefit to the multitude of ecosystem services that soils provide. This potential can only be realized by determining the amount of SOM stored in soils now, with subsequent quantification of how this is affected by management strate- gies intended to increase SOM concentrations, and used in soil C models for the prediction of the roles of soils in future climate change. An apparently obvious method to increase C stocks in soils is to augment the soil C pools with the longest mean residence times (MRT). Computer simulation models of soil C dynamics, e.g. RothC and Century, partition these refractory constituents into slow and passive pools with MRTs of centuries to millennia. This partition- ing is assumed to reflect: (i) the average biomolecular properties of SOM in the pools with reference to their source in plant litter, (ii) the accessibility of the SOM to decomposer organisms or catalytic enzymes, or (iii) constraints imposed on decomposition by environmental conditions, including soil moisture and temperature. However, con- temporary analytical approaches suggest that the chemical composition of these pools is not necessarily predictable because, despite considerable progress with understanding decomposition processes and the role of decomposer organisms, along with refinements in simulation models, little progress has been made in reconciling biochemical properties with the kinetically defined pools. In this review, we will explore how advances in quantitative analytical techniques have redefined the new understanding of SOM dynamics and how this is affecting the development and application of new modelling approaches to soil C.
Keywords: C isotopes, decomposition, recalcitrance, soil C models, soil microorganisms, soil organic matter
Located in
Resources
/
Climate Science Documents
-
Soil Temperature following Logging-Debris Manipulation and Aspen Regrowth in Minnesota: Implications for Sampling Depth and Alteration of Soil Processes
-
Soil temperature is a fundamental controller of processes influencing the
transformation and flux of soil C and nutrients following forest harvest. Soil
temperature response to harvesting is influenced by the amount of logging
debris (biomass) removal that occurs, but the duration, magnitude, and depth
of influence is unclear. Logging debris manipulations (none, moderate, and
heavy amounts) were applied following clearcut harvesting at four aspendominated
(Populus tremuloides Michx.) sites in northeastern Minnesota, and
temperature was measured at 10-, 30-, and 50-cm depths for two growing
seasons. Across sites, soil temperature was significantly greater at all sample
depths relative to uncut forest in some periods of each year, but the increase
was reduced with increasing logging-debris retention. When logging debris
was removed compared to when it was retained in the first growing season,
mean growing season soil temperatures were 0.9, 1.0, and 0.8°C greater at
10-, 30-, and 50-cm depths, respectively. These patterns were also observed
early in the second growing season, but there was no discernible difference
among treatments later in the growing season due to the modifying effect of
rapid aspen regrowth. Where vegetation establishment and growth occurs
quickly, effects of logging debris removal on soil temperature and the processes
influenced by it will likely be short-lived. The significant increase in
soil temperature that occurred in deep soil for at least 2 yr after harvest
supports an argument for deeper soil sampling than commonly occurs in
experimental studies.
Located in
Resources
/
Climate Science Documents
-
Soil warming, carbon–nitrogen interactions, and forest carbon budgets
-
Soil warming has the potential to alter both soil and plant processes that affect carbon storage in forest ecosystems. We have quantified these effects in a large, long-term (7-y) soil-warming study in a deciduous forest in New England. Soil warming has resulted in carbon losses from the soil and stimulated carbon gains in the woody tissue of trees. The warming-enhanced decay of soil organic matter also released enough additional inorganic nitrogen into the soil solution to support the observed increases in plant carbon storage. Although soil warming has resulted in a cumulative net loss of carbon from a New England forest relative to a control area over the 7-y study, the annual net losses generally decreased over time as plant carbon storage increased. In the seventh year, warming-induced soil carbon losses were almost totally compensated for by plant carbon gains in response to warming. We attribute the plant gains primarily to warming- induced increases in nitrogen availability. This study underscores the importance of incorporating carbon–nitrogen interactions in atmosphere–ocean–land earth system models to accurately simulate land feedbacks to the climate system.
climate system feedbacks | ecological stoichiometry | forest carbon budget | forest nitrogen budget | global climate change
Located in
Resources
/
Climate Science Documents
-
Solem 1974.pdf
-
Located in
Resources
/
TRB Library
/
SIM-SPA
