Ecological laws for agroecological design: the need for more organized collaboration in producing, evaluating and updating ecological generalizations.

The applied discipline of agroecological design provides a useful case study for examining broader philosophical questions about the existence and importance of ecological generalizations or "laws." Recent developments in the availability and use of formal meta-analyses have led to the discovery of many resilient generalizations in ecology (Linquist et al. 2016). However, these "laws" face numerous challenges when it comes to their practical application. Concerns about their reliability and scope might stem from unclear logical and epistemic connections to more foundational or "unifying" generalizations (Lean in Philos Top 47(1), 2019) which, in ecology, tend to be derived from first principles and in association with highly abstract models. This raises questions about the nature of those foundational generalizations themselves. In particular, how resilient are they compared to the generalizations uncovered by empirically driven methods? Here we propose a procedure for evaluating the resilience of generalizations across five ecologically relevant dimensions. This procedure was applied to seven well known foundational generalizations in ecology. Surprisingly, it turned out to be impossible to estimate the resilience of these foundational generalizations based on the available literature. This points to the need for a more centralized repository of information about ecological generalizations, created with the explicit aim of evaluating such important dimensions as causal mechanism and predictive power.

Earthworms do not increase greenhouse gas emissions (CO2 and N2O) in an ecotron experiment simulating a three-crop rotation system.

Earthworms are known to stimulate soil greenhouse gas (GHG) emissions, but the majority of previous studies have used simplified model systems or lacked continuous high-frequency measurements. To address this, we conducted a 2-year study using large lysimeters (5 m2 area and 1.5 m soil depth) in an ecotron facility, continuously measuring ecosystem-level CO2, N2O, and H2O fluxes. We investigated the impact of endogeic and anecic earthworms on GHG emissions and ecosystem water use efficiency (WUE) in a simulated agricultural setting. Although we observed transient stimulations of carbon fluxes in the presence of earthworms, cumulative fluxes over the study indicated no significant increase in CO2 emissions. Endogeic earthworms reduced N2O emissions during the wheat culture (- 44.6%), but this effect was not sustained throughout the experiment. No consistent effects on ecosystem evapotranspiration or WUE were found. Our study suggests that earthworms do not significantly contribute to GHG emissions over a two-year period in experimental conditions that mimic an agricultural setting. These findings highlight the need for realistic experiments and continuous GHG measurements.