Pastoral Burning and Its Contribution to the Fire Regime of Alto Minho, Portugal

Abstract

Alto Minho (in northwestern Iberia) is one of the European regions most affected by fires. Many of these fires originate from rangeland management of Atlantic heathlands, and, while being illegal, often are not actively suppressed. In this study, pastoral fires (autumn-to-spring fires unrecorded by authorities), spring wildfires, and summer wildfires were independently mapped and dated from remote sensing. Alto Minho burned at a mean annual rate of 5.0% of the territory between 2001 and 2020. Pastoral burning totalled 40,788 hectares during the period, accounting for 20% of the total burnt area. Rangeland burning occurs mostly from December to April, the rainiest months that guarantee the conditions for pasture renewal and fire self-extinction. The mean fire return interval of pastoral burning is slightly higher than that of wildfires (13 years vs. 11 years), except in part of the inner mountains where it dominates fire activity. Pastoral fires are more frequent and largely prevail over wildfires in the parishes with higher livestock quantities. Conversely, the largest wildfires and higher summer burnt areas correspond with very low livestock and nearly non-existing pastoral fires. Traditional fire knowledge should not be overlooked by fire management, as it contributes to more sustainable fire regimes and ecosystems.

Optimizing Wildfire Prevention through the Integration of Prescribed Burning into ‘Fire-Smart’ Land-Use Policies

“…Our results broadly support the use of fire as a management tool toward making landscapes more resistant to future wildfires [36,37,57,69]. The spatial extent of PF treatments is critical regarding the disruption of the wildfire rate of growth and the consequent decrease in area burned [28].…”

“…The use of fire as preventive tool has been clearly undermined by the current fire suppression paradigm in Southern Europe, which aims to exclude all types of fires from the landscape without considering their ecological and socioeconomic roles [36]. Despite these fire-exclusion policies, some regions are often subjected to frequent human-induced Based on the historical wildfire data, burn probability is high in certain regions of both countries, with some critical locations having an approximate fire return interval of three years [52].…”

“…The use of fire as preventive tool has been clearly undermined by the current fire suppression paradigm in Southern Europe, which aims to exclude all types of fires from the landscape without considering their ecological and socioeconomic roles [36]. Despite these fire-exclusion policies, some regions are often subjected to frequent human-induced wildfires with various causes (e.g., vandalism, arson, revenge, land-use change attempts, territorial disputes, and mental problems) but rooted in profound socioeconomic changes [53][54][55].…”

“…Our model simulations point toward an urgent paradigm shift, centered on 'fire-smart' management, which should aim to mitigate fire severity through fuel treatments accompanied by land-use conversions (preferably to fireresistant or fire-resilient vegetation types). This change will require the valorization of rural spaces, the reintroduction of agropastoral activities, the recognition of traditional knowledge and practices of the local population, such as shepherds and traditional fire users [36,75], the promotion of resources, the support for population settlement to drive this change at local levels, and a shift in how wildfires are managed, fought, and prevented. The first step is to raise awareness among organizations and public decision makers about the growing need to act at the landscape scale to reverse current policies that contribute to the escalating cycle of highly flammable landscapes.…”

“…Prescribed fire (PF) can decrease surface and ladder fuels, which subsequently reduces potential fire behavior and the risk of crown fire and spotting [31], thus reinforcing fire prevention policies [32][33][34]. Fighting fire with fire represents an important paradigm shift after decades of fire-exclusion policies, with widely demonstrated positive effects in terms of fire risk reduction, especially in fire-adapted ecosystems [28,[35][36][37]. Prescribed fire involves the planned and controlled use of fire, following a predefined prescription, to achieve specific and well-defined resource management goals.…”