ecology

Soil: Earth’s Living Tapestry

Beneath our feet lies an intricate tapestry of life, teeming with activity: soil. Often overlooked, the health and complexity of this living canvas significantly influence the sustainability of life as we know it (Lavelle and Spain, 2001). Soil ecology delves deep into this tapestry, studying the interactions between soil-dwelling organisms and their environment. The importance of this discipline is monumental, revealing how different organisms contribute to nutrient cycling, soil formation, and overall ecosystem functions (Bardgett, 2005).

The Day in a Life of a Soil Ecologist

Soil ecologists unravel the mysteries of soil ecosystems. Their endeavors range from microscopic analyses of soil microbes to broader studies addressing the soil’s impact on climate. Here’s a glimpse into their typical day:

Fieldwork: They might be collecting soil samples, setting up experiments, or taking environmental measurements (Wardle, 2002).

Laboratory Analyses: They delve into soil samples, identifying organisms, or measuring soil properties. They might use everything from basic microscopy to advanced methods like DNA sequencing (Fierer & Jackson, 2006).

Data Analysis: A lot of their time goes into analyzing data, using statistical software, and even crafting mathematical models to predict soil processes (Manzoni & Porporato, 2009).

Writing & Publishing: Like many scientists, they share their findings through scientific papers, enhancing the collective knowledge of the community (Bardgett, 2005).

Whereas the studies of soil ecologists may range in focus–say from examining agricultural practices’ impacts on soil health to exploring soil organisms’ roles in climate change (Doran & Zeiss, 2000; Six et al., 2002)– the results can benefit various sectors, from academia and government agencies to the private sector and non-profits.

See the video below for an interview with soil ecologist Dr. Yamina Pressler.

The Soil’s Biodiverse Orchestra

Imagine this: a single gram of soil could be bustling with up to a billion bacteria (Whitman et al., 1998). The soil is a realm of staggering diversity: bacteria, fungi, protozoa, nematodes, and many more. They all dance in a complex web of life, supporting functions like decomposition, nutrient cycling, and disease suppression (Bardgett and van der Putten, 2014).

Microscopic image from Bauber and Dindaroğlu 2020 labeling components of soil sample.

In harmony, their collective efforts sculpt the soil. Diligent earthworms, for instance, burrow, aerating the soil and aiding water infiltration. Fungi, with their hyphal networks, bind soil particles, fortifying the soil structure (Ritz & Young, 2004). Some soil warriors even defend against plant diseases. We see this in certain strains of bacteria and fungi. For example, the fungus Penicillium chrysogenum produces antibiotics, effectively staving off pathogens, serving as nature’s own pest management system (Mendes et al., 2011).

Soil: Our Climate Guardian

Soil biota play pivotal roles in the cycling of essential elements like carbon, nitrogen, and phosphorus (Coleman et al., 2004). Bacteria and fungi act as recyclers, breaking down organic matter and releasing nutrients. Some bacteria, the nitrogen-fixers, even draw nitrogen from the air, converting it into a plant-friendly form (Vitousek et al., 2002). See the image below for a representation of the nitrogen cycle, emphasizing the role of soil organisms (Source: Bioninja).

Soils could also be considered a form of climate guardian, holding more carbon than both the atmosphere and all vegetation. Disturbances to soil, like deforestation and poor agricultural practices, can lead to the release of this stored carbon into the atmosphere, contributing to greenhouse gas emissions. Conversely, healthy, well-managed soils can sequester carbon from the atmosphere, potentially mitigating climate change and emphasizing the urgency to manage and protect them diligently (Lal, 2004; Paustian et al., 2016).

The image to the right displays a schematic of potential pathways for CO2 molecule once sequestered from the atmosphere through the soil (Ontl and Schulte, 2012). Carbon balance within the soil (brown box) is controlled by carbon inputs from photosynthesis and carbon losses by respiration. Decomposition of roots and root products by soil fauna and microbes produces humus, a long-lived store of soil organic carbon.

See the recommended video below for an in-depth look at where soil fits into the carbon cycle.

In Conclusion

The soil is not just dirt beneath our feet; it’s an intricate world, pulsating with life! Most importantly, this reminds us of the profound interconnectedness of our planet. Every grain, every microbe, and every root tells a story of life’s incredible resilience and interdependence. Soil ecology, with its myriad interactions and functions, is a cornerstone for the Earth’s biosphere. It is a compelling testament to the interconnectedness of life and a crucial piece of the puzzle in addressing global challenges such as food security and climate change. As we discover the secrets whispered by the earth, we gain insights into addressing global challenges and securing a future for generations to come. So, as you tread the Earth, pause and appreciate the delicate symphony beneath, remembering the vital tune it plays for our planet’s future.

Stay Adventurous,
Olivia Grace

References

Bardgett, R. (2005). The Biology of Soil: A Community and Ecosystem Approach. Oxford University Press.

Bardgett, R. D., & van der Putten, W. H. (2014). Belowground biodiversity and ecosystem functioning. Nature, 515(7528), 505–511.

Coleman, D.C., Crossley, D.A., Hendrix, P.F. (2004). Fundamentals of Soil Ecology. Academic Press.

Lal, R. (2004). Soil carbon sequestration to mitigate climate change. Geoderma, 123(1-2), 1-22.

Lavelle, P., & Spain, A. V. (2001). Soil Ecology. Kluwer Academic Publishers.

Mendes, R., Kruijt, M., de Bruijn, I., Dekkers, E., van der Voort, M., Schneider, J. H., Piceno, Y. M., DeSantis, T. Z., Andersen, G. L., Bakker, P. A., & Raaijmakers, J. M. (2011). Deciphering the Rhizosphere Microbiome for Disease-Suppressive Bacteria. Science, 332(6033), 1097-1100.

Ontl, T. A. & Schulte, L. A. (2012) Soil Carbon Storage. Nature Education Knowledge 3(10):35

Paustian, K., Lehmann, J., Ogle, S., Reay, D., Robertson, G.P., Smith, P. (2016). Climate-smart soils. Nature, 532(7597), 49-57.

Ritz, K., & Young, I. M. (2004). Interactions between soil structure and fungi. Mycologist, 18(2), 52-59.

Smith, S. E., & Read, D. J. (2008). Mycorrhizal Symbiosis. Academic Press.

Vasilas et al., 2016: researchgate.net/figure/The-soil-profile-ab-ve-consists-of-an-8-cm-314-inches-layer-of-peat-and-or-mucky-peat_fig1_318239569

Vitousek, P.M., Menge, D.N., Reed, S.C., Cleveland, C.C. (2013). Biological nitrogen fixation: rates, patterns and ecological controls in terrestrial ecosystems. Philosophical Transactions of the Royal Society B, 368(1621), 20130119.

Whitman, W.B., Coleman, D.C., Wiebe, W.J. (1998). Prokaryotes: the unseen majority. Proceedings of the National Academy of Sciences, 95(12), 6578-6583.

Bardgett, R. (2005). The Biology of Soil: A Community and Ecosystem Approach. Oxford University Press.

Wardle, D. (2002). Communities and Ecosystems: Linking the Aboveground and Belowground Components. Princeton University Press.

Fierer, N., & Jackson, R. B. (2006). The diversity and biogeography of soil bacterial communities. Proceedings of the National Academy of Sciences, 103(3), 626-631.

Manzoni, S., & Porporato, A. (2009). Soil carbon and nitrogen mineralization: Theory and models across scales. Soil Biology and Biochemistry, 41(7), 1355-1379.

Doran, J. W., & Zeiss, M. R. (2000). Soil health and sustainability: managing the biotic component of soil quality. Applied Soil Ecology, 15(1),

Rutgers, Michiel & Mulder, Christian & Schouten, Ton. (2008). Soil ecosystem profiling in the Netherlands with ten references for biological soil quality. RIVM Report. 60760400. 1-89.

In 2019, a group of researchers from Rice University created a reactor capable of reducing atmospheric carbon dioxide into a usable energy source: formic acid. Formic acid fuel-cell energy is a better long-term alternative than utilizing hydrogen fuel-cell energy—as researchers indicate hydrogen gas is harder to get into a condensed state. Head researcher Haotian Wang was able to create this reactor by eliminating a need for salts in the solution. Typically, salts have been used for reducing atmospheric carbon dioxide, but Wang suggested to instead use a solid electrolyte that degrades more slowly. Not only was this created catalyst slower in degradation, it was also more stable (held form during the reaction). Success rate for this reactor depended on the speed at which the reaction took place; higher speeds gained better results, and researchers achieved nearly a 50% collection of formic acid at the end of the trials.

While producing a useful and strong biochemical fuel, the lab’s research primarily aimed to reduce the amount of greenhouse gasses in the atmosphere. Global warming is a threat to our planet and the multitude of species that inhabit it. A continual increase in greenhouse gasses would only accelerate the effects of global climate change. The research being done at Rice University holds tremendous value toward conservation efforts, because by lowering greenhouse gas concentrations in the atmosphere, the resulting stress effects these gasses hold on species could lessen overtime. A decreased presence of external stressors on a population can significantly decrease an organism’s vulnerability to extinction. While this reactor is still a prototype in the lab, researchers feel they could scale their methods to work at industry level, which would allow this method of lowering greenhouse gasses to extend to international use. Ensuring high carbon-emitting, industrialized countries have access to this technology holds potential to make climate conservation on the multinational level much more attainable. Combating climate change is one of the most important issues in ensuring the conservation of our planet’s species, and while more testing and tinkering with the reactor is needed, this process is a step in righting the damage done.

Wang and his team were published in Nature Communications in 2020. If you would like to read the paper released, you can find it here.

Since publishing this paper, the Wang Lab has received many awards for their continued research into the use of reactors to isolate compounds from the environment. More recently, scientists in the Wang Lab have discovered a more efficient way of synthesizing Hydrogen Peroxide (H2O2) from environmental factors using a boron-attached carbon molecule as fuel, or a catalyst, for the collection pathway. Hydrogen peroxide is an oxidizing chemical commonly used in scientific research and medicinal practices. In prior years to now, synthesizing hydrogen peroxide was difficult to achieve due to the the reactive favorability of the molecules involved to convert to water. The pathway perfected by the Wang Lab research team allows for more stabile accumulation process of hydrogen peroxide molecules, well as higher ratios of molecule collected.

Haotian Wang and the researchers in his lab continue their efforts in molecular synthesis as it related to environmental cleanup, and are making headlines among environmental and biochemists worldwide. If you would like to keep up with the efforts from the research team, you can follow the University’s update page here.