Soil health is key to ensuring food security, but it is currently under threat from global climate change. In response, scientists have attempted to understand the range of impacts this is having using biological indicators to inform the implementation of strategies which adapt to the effects of climate change.
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How climate change impacts soil health
The advent of global climate change is a major challenge for human populations as it is impacting food production. This is due to the multifaceted repercussions of largescale effects such as global warming, which is affecting crop viability, increasing the occurrence of pests and pathogens, and deteriorating soil health.
In particular, soil health refers to the agronomic function of soil, directly relating to the sustainable production of crops as well as animals, while also improving the overarching environment.
Over recent years, mounting scientific evidence has indicated that soil health will be adversely affected by climate change by reducing soil organic matter content, decreasing soil structure, and increasing vulnerability to erosion and other degradation processes. These mechanisms are also exacerbated by other anthropogenic impacts including pollution, widespread habitat degradation, and the introduction of invasive species.
Such mechanisms will reduce the capacity to maintain sustainable crop production as well as limit the exploitation of new crop systems, ultimately limiting food security into the future.
To accurately project and therefore mitigate the effects of global climate change on soil health and its repercussions on food security, it is key to understand the full range of impacts.
Understanding the diversity of impacts on soil health
In a study by Anamika Dubey and colleagues published in the journal Biodiversity and Conservation in 2019, scientists provided an in-depth view of the complexity in soil systems and how global climate change affects the balance within them.
Specifically, researchers explored how plant-associated microbial communities will be affected by global climate change. These communities are key to soil systems as they stimulate plant growth and increase resistance to abiotic and biotic stresses. As such, the scientists reviewed how climate change affects soil microbial communities and their associated plant-microbe interactions.
The researchers found that soil microbial taxa play a significant role in regulating the effects of climate change as they are central to mechanisms such as biogeochemical cycling, plant growth, and health as well as soil carbon sequestration.
In response, the study suggested microbial systems could be harnessed to offset some of the effects of global climate change, particularly through the use of genomic approaches. Modern genomic approaches can be used for the identification of uncultivated diversity, finding changes in bacterial communities associated with resilient or sensitive crop types, and providing a valuable tool to assess the responses to climate change.
Nonetheless, the authors advocated for further research to be conducted on the multi-stressor synergy of climate change alongside pollution and soil degradation from agricultural practices such as artificial fertilizers, which are known to degrade soil microbial communities.
Understanding the full extent of effects, as well as their interactions with other human-driven stressors, will be essential to projecting the effects of global climate change as well as identifying the most promising approaches to mitigate such effects.
Soils: Our ally against climate change
Quantifying soil health impacts of climate change
To better understand such impacts, the use of biologically relevant indicators has become increasingly popular over recent decades. This is particularly true when addressing the impacts of environmental change on soil health, as impacts can be observed across biotic and abiotic factors from community composition to carbon sequestration.
Indicators are key tools as they relate directly to the physical, chemical, and biological properties or ecological functions of soil systems which can be monitored in the context of land management and climate change.
In a 2011 study by Diane Allen et al., scientists reviewed the range of indicators used to understand the effects of climate change as well as the factors associated with their accuracy.
The study first discussed how soil texture, tilth, color, biodiversity, water intake rate, the likelihood of drought, internal drainage, and resilience against perturbation, are most commonly used as indicators for soil health.
Authors then found that indicators most used in the context of global climate change research included aggregate stability, water infiltration, and bulk density, soil organic matter content, carbon and nitrogen cycling, microbial biomass and activity, and microbial diversity.
This is primarily due to the mechanistic impacts of climate change which include increasing temperatures, elevated atmospheric carbon dioxide, and atmospheric nitrogen deposition, increasing extreme climatic events, and their interactions since these impacts interact directly with the common indicators.
Measures using indicators can therefore be used across policies, including the implementation of early warning systems, identifying areas most at risk, and implementing effective strategies for mitigation and adaptation.
The study then discusses how indicators require a minimum data set encompassing accurate data sensitive to management is required to use indicators effectively. Moreover, effective indicators of soil health need to integrate and relate to other soil functions, be easy to use, and have high repeatability as well as a low cost of measurement.
The authors conclude by discussing how indicators can be tested prior to implementation, and emphasize the rising concern of climate change impacts as well as the strong link between soil health and human health which highlights the need for effective measures addressing soil health.
- Allen, D. E., Singh, B. P., & Dalal, R. C. (2011). Soil Health Indicators Under Climate Change: A Review of Current Knowledge. Soil Biology, 25–45. doi:10.1007/978-3-642-20256-8_2
- Briones, M. J. I., Ostle, N. J., McNamara, N. P., & Poskitt, J. (2009). Functional shifts of grassland soil communities in response to soil warming. Soil Biology and Biochemistry, 41(2), 315–322. doi:10.1016/j.soilbio.2008.11.003
- Dubey, A., Malla, M. A., Khan, F., Chowdhary, K., Yadav, S., Kumar, A., Sharma, S., Khare, P. K., &Khan, M. L. (2019). Soil microbiome: a key player for conservation of soil health under changing climate. Biodiversity and Conservation, 28(8–9), 2405–2429. doi:10.1007/s10531-019-01760-5
- Lal, R. (2011). Soil Health and Climate Change: An Overview. Soil Biology, 3–24. doi:10.1007/978-3-642-20256-8_1