Determining bioclimatic space of Himalayan alder for agroforestry systems in Nepal

Abstract

Himalayan alder species are proven to be very useful in traditional as well as contemporary agroforestry practice. These nitrogen-fixing trees are also useful in the land restoration. Therefore, understanding the distribution of Himalayan alder and the potential zone for plantation is meaningful in the agroforestry sector. Suitable climatic zones of Alnus spp. were modelled in MaxEnt software using a subset of least correlated bioclimatic variables for current conditions (1950–2000), topographic variables (DEM derived) and Landuse Landcover (LULC) data. We generated several models and selected the best model against random models using ANOVA and t-test. The environmental variables that best explained the current distribution of the species were identified and used to project into the future. For future projections, ensemble scenarios of climate change projection derived from the results of 19 Earth System Models (ESM) were used. Our model revealed that the most favorable conditions for Alnus nepalensis are in central Nepal in the moist north-west facing slope, whereas for Alnus nitida they are in western Nepal. The major climatic factor that contributes to Alnus species distribution in Nepal appears to be precipitation during the warmest quarter for A. nepalensis and precipitation during the driest quarter for A. nitida. Future projections revealed changes in the probability distribution of these species, as well as where they need conservation and where they can be planted. Also, our model predicts that the distribution of Alnus spp. in hilly regions will remain unchanged, and therefore may represent sites that can be used to revitalize traditional agroforestry systems and extract source material for land restoration.

Climate change adaptation in and through agroforestry: four decades of research initiated by Peter Huxley

“…With the wealth of climate data now available and the 'Big Data' toolbox of analysis, the question of which climate variables have the most skill in accounting for tree distributional patterns can be tackled more directly. For example, Rana et al (2018) developed MaxEnt models of recorded Alnus species distribution data in Nepal, using a subset of least correlated bioclimatic variables for current conditions , topographic variables and Land Use Land Cover (LULC) data. The major climatic factor that contributes to Alnus nepalensis distribution in Nepal appears to be precipitation during the warmest quarter of the year and precipitation during the driest quarter for Alnus nitida.…”

Revisiting Agroforestry for Building Climate Resilient Communities: A Case of Package-Based Integrated Agroforestry Practices in Nepal

“…As an integration of forestry component with crops and/or livestock, agroforestry can contribute for mitigation as well as adaptation to climate change [5]. Traditional agroforestry practices are believed to be unique practice in mountainous region of Nepal, allowing promising solution for land restoration and slope cultivation [6,7]. At the same time, agroforestry has potential for sustainable land management to contribute to rural livelihood and environmental benefits [7].…”

Agroforestry for mountain development: Prospects, challenges and ways forward in Nepal

“…In addition, there is a possibility to incorporate value chain and landscape approaches into agroforestry systems because, not only climatic factors such as temperature and precipitation but also market may determine the opportunity for agroforestry systems. whereas for A. nitida they are in western Nepal (Rana et al, 2018). Future distribution of these species determined by the precipitation during the warmest quarter (for A. nepalesis) and the driest quarter (for A. nitida).…”

“…At present, about 24% of the total area of Nepal is suitable for the species-the central region is the most suitable, whereas the western region has a dispersed distribution suitability. The future species distribution in the hilly region will remain unchanged and most favored along the river valleys, however predicted a northward shift under the future climate change (Rana et al, 2018). Such data on the Alnus species is essential for adaptive responses and preventive measures for the sustainable management of agroforestry tree species; however, there is a lack of data on the future distribution of the cardamom species.…”

“…Over the past decade, the demand of organic vegetables is increasing in Nepal, mostly in major cities, with increased public awareness on health, however, field level adoption of organic farming practices is so far limited (Bhatta et al, 2009;Pokhrel and Pant, 2009;Bhattarai, 2019). Regarding growing vegetables and fruits and fodder trees on farmland, home garden-based agroforestry system has a great value to local environment and people's livelihoods (Gautam et al, 2009;Rana et al, 2018;Sunwar et al, 2006). This farming practice occurs near to the homestead and provides farmers with increased diversity in their food crops.…”