Text by Lauri Laanisto
Community ecology was once famously described as ‘collecting stamps’ by John Lawton, as every community is so different and unique in so many ways. Therefore, instead of making generalisations, one can only study unique communities the way a collector studies their unique collection – a very post-truth-style statement from 20 years ago! However, Lawton was merely being provocative, and he actually suggests that there are indeed general laws in ecology – widespread, repeatable patterns, although not universally true in all cases.
Through the enormous bulk of ecological literature, it is very difficult to pinpoint these laws. Most of us, when publishing new results, tend to focus on the validity of the results and formulate found patterns as more or less general rules that might indeed hold unless specifically tested in other scales and places. As a result, there are a number of contradictory ideas and concepts floating around in ecological literature. Everything seems contingent.
So, sometimes little bubbles form in science, where some fundamentals have gone missing, or are discarded for some reason. The impulse to discard fundamentals might come, not from the theoretical thinking itself, but from something outside of it. For example, waste from agriculture and biotechnology, which needs to be offloaded somewhere and preferably cheaply. Combine it with the ‘balance of nature’ concept that is known not to work in ecological systems, and it might as well culminate in ‘let’s give back to nature’ type-thinking, which can result in spreading slurry in grasslands, or at its worst, a cynical approach to waste management
Our Commentary addresses several studies that have sought ways to get rid of waste by giving it back to where it originally came from – grasslands. Specifically, recent publications have recommended fertilising semi-natural temperate grasslands with nutrient residues like digestate and slurry. These studies claim that fertilising grasslands increases productivity but has no negative effect on species richness. We highlight three aspects that should be considered before fertilising diverse grassland communities, which are based on fundamental ecological knowledge and long-term experiments.
Everything is not necessarily contingent after all …
/This blog post was originally written and publised in JAPPL blog/ (link)
Citation: Melts, I., Lanno, K., Sammul, M., Uchida, K., Heinsoo, K., Kull, T., & Laanisto, L. (2018). Fertilising semi‐natural grasslands may cause long‐term negative effects on both biodiversity and ecosystem stability. Journal of Applied Ecology, DOI 10.1111/1365-2664.13129: (link to full text)Abstract:
- Some short‐term experiments in applied ecology and agricultural research have demonstrated that nutrient applications in semi‐natural grasslands can maintain productivity and will not result in the decrease of plant species richness. Such findings may have an impact on management choices and quality of valuable plant communities, and therefore, further discussion of this topic is necessary.
- We highlight three aspects regarding the management suggestions in grassland communities with high biodiversity: (1) short‐term study results may not reflect potential long‐term changes; (2) broad range of grasslands may respond to disturbance in site specific ways; and (3) practical advices should contain careful consideration of existing ecological literature regarding grassland management and sustainable biodiversity.
- Synthesis and applications. Considering effects of fertilisation on biodiversity, we argue against nutrient application to semi‐natural grasslands. Biodiversity supports the resilience of grassland ecosystems and maintains a stable biomass yield. Current short‐term experiments are good indicators about the need for a long‐term experiments and meta‐analysis for detailed understanding of ecosystem functions in different types and areas during global change.