Estimating resilience of crop production systems: From theory to practice

Abstract

Agricultural production systems are sensitive to weather and climate anomalies and extremes as well as to other environmental and socio-economic adverse events. An adequate evaluation of the resilience of such systems helps to assess food security and the capacity of society to cope with the effects of global warming and the associated increase of climate extremes. Here, we propose and apply a simple indicator of resilience of annual crop production that can be estimated from crop production time series. First, we address the problem of quantifying resilience in a simplified theoretical framework, focusing on annual crops. This results in the proposal of an indicator, measured by the reciprocal of the squared coefficient of variance, which is proportional to the return period of the largest shocks that the crop production system can absorb, and which is consistent with the original ecological definition of resilience. Subsequently, we show the sensitivity of the crop resilience indicator to the level of management of the crop production system, to the frequency of extreme events as well as to simplified socio-economic impacts of the production losses. Finally, we demonstrate the practical applicability of the indicator using historical production data at national and sub-national levels for France. The results show that the value of the resilience indicator steeply increases with crop diversity until six crops are considered, and then levels off. The effect of diversity on production resilience is highest when crops are more diverse (i.e. as reflected in less well correlated production time series). In the case of France, the indicator reaches about 60% of the value that would be expected if all crop production time-series were uncorrelated.

Annual Green Water Resources and Vegetation Resilience Indicators: Definitions, Mutual Relationships, and Future Climate Projections

“…The original meaning of the term resilience-first introduced in ecology-refers to the largest pressure that a system can cope with without changing its internal structure and losing its functioning capacity [28,30]. While the concept of resilience has evolved in complexity while spreading into other fields such as engineering and social sciences, a recent study [27] brought back the original ecological definition of resilience. The only assumption of that study is that severe shocks are rarer than moderate perturbances.…”

“…The only assumption of that study is that severe shocks are rarer than moderate perturbances. This allows measuring the severity of the shock by its return period and to formally derive a consistent statistical indicator that can be computed on annual production time series [27]. This section summarizes the main properties of the resilience indicator (R C ) and introduces its application to NDVI and precipitation data.…”

“…The resilience indicator for annual crop production [27] is defined as the squared mean divided by the squared standard deviation of annual production time series:…”

“…We estimate vegetation primary production resilience by means of the NDVI and its inter-annual variability. More specifically, we adopt the recently proposed indicator for annual crop production resilience [27]. This indicator is derived from the original ecological definition of resilience i.e., the measure of the largest stress that the system can absorb without losing its function [28].…”

“…Validity of the fundamental principle of the resilience indicator [27] applied to precipitation, i.e., its proportionality with drought return times.…”