Agroecosystem patterns and land management co‐develop through environment, management, and land‐use interactions

Abstract

A poor understanding of the interactions between biophysical and social elements within rural mountainous landscapes can lead to suboptimal management and recommendations. The objective of this study was to contribute to more contextualized natural resource management in a rural landscape in the Ecuadorian Andes by (1) identifying biophysical patterns in soil properties, biodiversity, and C stocks that emerge from natural landscape pedogenic processes, resulting from elevation-induced climate gradients, erosion and soil textural patterns, and (2) assessing farm management and land-use effects on and their interactions with these biophysical patterns. Our findings revealed that the climate and soil texture gradients within the landscape led to an exponential increase in SOC with elevation moderated by slope gradient, indicating significant erosion processes. Farmers adapted their farm management according to the observed environmental patterns creating three distinct management zones. Differentiated agricultural management in these zones and asymmetrical distribution of land-uses in turn were observed to significantly influence soil and agroecosystem properties. For example, available P was found to be significantly higher in the upper and middle agricultural management zones (24.0 and 28.7 mg/kg, respectively), where agricultural inputs were higher compared to the lower agricultural management zone (8.9 mg/kg, P < 0.001). Mixed hedgerows, on the other hand, displayed significantly higher Shannon index scores for ground vegetation (1.8) and soil macrofauna (2.0) compared to agricultural land-uses (1.0 and 1.7). Our results provide important insights into how agroecosystem patterns and land management co-developed through complex environment, management, and land-use interactions.

Land use conversion to agriculture impacts biodiversity, erosion control, and key soil properties in an Andean watershed

“…The significant co-inertia among plant cover, soil macrofauna communities, and soil physicochemical properties indicates a strong connection among the biophysical components that determine ecosystem function. Similar relationships were found when comparing different sets of variables in tropical savannah agroecosystems (Lavelle et al, 2014), the Amazon region (Grimaldi et al, 2014), and the Peruvian and Ecuadorian Andes, where land use drives biodiversity and the provision of multiple ES (Caulfield et al, 2020;de Valença et al, 2017). Such generalized correlations support the hypothesis proposed that transforming plant communities leads to indirect management of soil fauna communities and ES that depend on their activities.…”

“…This decline in the provision of ES at a global scale highlights the need to develop alternative agroecosystems that can maintain productivity, but also generate multiple ES, especially in areas of high biodiversity and ecological fragility (Bennett et al, 2009). In the Andean region, the intensification of these agricultural landscapes can have considerable effects on ES with regard to soil processes, leading to decreased fertility (Caulfield et al, 2020; de Valença et al, 2017), reduced water infiltration potential, lower water holding capacity, and decreased soil stability and erosion control (Guzman et al, 2019; Otero et al, 2011; Zimmerer, 1993). Increased use of fertilizers with agricultural intensification can increase food and fiber production (Rolando et al, 2018), but often diminishes the provision of other ES related to hydrological function and water quality (Bennett et al, 2009; Rolando et al, 2017).…”

Drivers of farmer involvement in experimental forage trials in the Peruvian Andes and implications for participatory research design

“…The important role of access to irrigation, land-use intensity and overall accessibility demonstrates the importance of management by context, whereby farmers manage their fields which are spread out across a particular landscape depending on the location of the fields. As shown in a number of studies now, both biophysical landscape patterns such as variations in soil fertility and human factors such as distance from homestead drive important differences in agricultural management (Caulfield et al., 2020c; Caulfield et al., 2020d; Van Apeldoorn et al., 2013). Coupled with a number of socio-ecological trends in the Andes such as enhanced transport infrastructure, migration, land-use change and climate change among others (Curatola Fernández et al., 2015; de Valença et al., 2017; Fonte et al., 2012), this raises a number of important questions regarding the potential role of these improved fallow techniques in the rural Andes in the future.…”

Inter‐community and on‐farm asymmetric organic matter allocation patterns drive soil fertility gradients in a rural Andean landscape

“…Further research is necessary to explore the drivers behind these well‐recognized asymmetric resource allocation patterns in agricultural landscapes, so as to develop more contextualized pathways for improving the overall fertility and productivity of farms. For example, if the main constraint on increasing soil fertility of distant fields is one of logistics and labor, rather than access to resources, a better solution for improving productivity may be the promotion of in situ approaches to increasing nutrient and OM inputs, such as through the use of green manures, forage rotations with direct grazing, or alternative cropping systems that reduce nutrient exports (Caulfield et al, 2020). In the event that an asymmetric OM allocation involved broader risk management strategies whereby the fertile infields were used for reliable crop production, while the outfields were used as low investment ‘bets’, a deeper discussion around risk management and sustainable land management may be more fruitful (Goland, 1993).…”