Blog Post by Krista Marshall, PhD student
Ecological biodiversity – including who’s there (plants, animals, insects, microbes, etc.), what they are doing (functionality), and with whom they’re interacting with – has long been recognized as a driver of the internal regulation and functional potential of agroecosystems. Ecosystem biodiversity, be it of a forest, grassland, agroecosystem, city, is therefore critical to maintaining and potentially improving the ecosystem services that we rely on. This is particularly important when we discuss agroecosystems because, for much of modern farming history, we have simplified and intensively managed arable landscapes, enabling us to substitute essential ecosystem functions and processes with agricultural inputs. However, it is now well documented that the health, resilience, and long-term productivity of our agroecosystems relies on biodiversity and ecosystem complexity and cannot be sustained solely through inputs and intensive management. It is also increasingly imperative that agroecosystems provide diverse environmental, economic, and sociopolitical services that place an emphasis on the sustainability, stability, resilience, and equity of agricultural productions.
To someone who relishes in the interconnected and complex nature of our food and agricultural system, myself included, the burgeoning paradigm shift to diversify our agricultural landscapes and embrace systems that support a diversity of benefits keeps my mind turning into the night and greets me first thing in the morning. But to a scientist, myself also included, trying to actually wrap your head around not only understanding agroecological systems and biodiversity across multiple scales, but also identifying meaningful and accurate methods of researching these systems can honestly leave your mind inundated and overloaded. Despite finding yourself deeply entangled in these puzzles, this research offers endless opportunities to work in agricultural landscapes, discover inspiration through observations of the world, and explore how we can best measure the phenomena we observe – with the goal of piecing together the large and complex puzzle that is our food and agricultural system. These opportunities are also both fundamental components of the scientific process itself and experiences that are invaluable for developing an appreciation for the natural systems and processes that support us.
Given that I’ve now finished my first field season – and year – as a graduate student working in an agroecology lab, I thought that writing this blog post would be the perfect opportunity to reflect on my own experience spending time in the systems that I study – observing how the design and management of our agroecosystems impacts biodiversity and the environment. I also hope, that in sharing my experiences, I might inspire others to observe, ponder, and find wonder in the landscapes around us.
As I mentioned before, I find myself drawn towards and humbled by the complexities of our food and agricultural system.
However, this orientation can sometimes oppose the goal of pursuing a graduate degree in which you generally work to
develop an expertise. This is one of the many reasons I’m endlessly grateful to work on a project and be part of a team that thoughtfully balances developing focus and breadth. I’m inspired and excited by the research we do! It comes as no surprise, then, that my project focuses on exploring the potential benefits and tradeoffs of soil health for production and sustainability outcomes. By the nature of my project, I got to spend lots of time doing fieldwork in almond orchards that spanned a variety of management practices, sizes, and levels of agroecological biodiversity (figure 1). I spent the better part of 2019 going on tours around Davis, CA with my major professor and a farm advisor searching for almond orchards that we could include in our study. By April, we’d decided to include 13 orchards, and I spent the following month driving across the county to different sites, getting tours of farms, and spending entire days outside taking soil samples and observing the landscape.
The orchards I work in span a wide variety of practices and sizes – from small-scale diversified farms where the livestock-grazed, pasture understories of their almond orchards were one of a multitude of crops grown to hundreds of acres that comprised solely almond trees with bare soils. Although I’ve just started analyzing the data collected for my project, there were visually apparent differences in the soils of each production system. The soils from orchards with continuous vegetation, like those using pastures, had soils that were visually darker, easy to retrieve samples from, and weren’t dusty in the slightest, which suggests that there could be much higher levels of soil organic matter – a component of the soil that drives many soil health outcomes. In addition to differences in the soils themselves, the most dramatic distinction I observed between the orchards was the visible and audible difference in both the soil and aboveground life. Orchards that were using practices that included cover crops, pasture and grazing, and/or organic amendments hosted a diversity of soil organisms like earthworms, beetles, spiders, ants, and isopods (which you may know as roly polies) (figure 2, see the video here! ). However, what really distinguished these orchards was the aboveground life, which included bees, birds, frogs, and larger animals, just to name a few. There seemed to be noticeably more aboveground life in orchards that were using a diverse mixture of cover crops or pasture and were part of a larger diversified production and/or situated close to non-agricultural landscapes. Something about these orchards felt different – more complex, livelier, dare I say healthier overall than the standard orchard that is ubiquitous across California. This observation, to me, solidified why enhancing agroecological biodiversity, across farms and landscapes, is so vitally important to ecosystem function and health as well as sustainability and productivity outcomes.
These observations got me thinking two things: one, that I wish I’d included a component in my project that explored how the practices used by each grower impact the diversity of organisms their productions host. But this reflection can’t necessarily be avoided, especially when you focus on systems research so I’ll embrace that I might frequently feel this way… for now. The second, and more intriguing, reflection is broad in scope and has had me contemplating how the planned design and management of agroecological biodiversity, across farms and landscapes, influences associated biodiversity, ecosystem service potential, and overall ecosystem health. Specifically, I’ve been wondering what are the most accurate and relevant ways in which we can measure the impacts of the design and management of our agroecosystems on associated biodiversity? Subsequently, how does the resulting associated biodiversity function to support ecosystem (dis)services and, ultimately, the sustainability and productivity of our agroecosystems? And finally, how can we leverage our understanding of these relationships to create policies and programs that support agroecosystems that are designed and managed to enhance biodiversity, sustainability, and productivity?
I’m not the only one pondering these questions. There is an ever increasing body of knowledge that is exploring and establishing relationships between the design and management of our agroecosystems, associated biodiversity, and ecosystem (dis)services. And although it is well understood that agriculture can have detrimental impacts on biodiversity, both within the farm itself and across landscapes, getting the opportunity to immerse myself and make observations about the many components of our agroecosystems has been an invaluable experience for validating the positive potential of agroecological practices as well as generating future research questions that complement my current work. As scientists, advocates for food and agricultural systems that provide a multitude of services for all people, and generally curious souls seeking to understand the world around us, observation is our most powerful tool for inspiring endless scientific questions and appreciating the complexities and intricacies of our ecosystems. So the next time you are working on an experiment, doing fieldwork, or simply find yourself with a moment to observe, use that opportunity to take in all that’s around you – it may just be your next aha moment.