A spatal and temporal assessment of fre regimes on different vegetaton types using MODIS burnt area products

Abstract

Background: The role of fre in maintaining grassland diversity has been widely recognised; however, its effect in KwaZulu-Natal grasslands is still rudimentary. In that regard, understanding fre regimes of different vegetation types in KwaZulu-Natal is a critical step towards the development of effective management strategies that are specifc to each vegetation type. Objective: To assess the effect of different vegetation types on fre regimes in KwaZulu-Natal using moderate resolution imaging spectroradiometer (MODIS) burnt fre products. Method: Ten years of fre data for four different vegetation types (Ngongoni Veld, KwaZuluNatal Sandstone Sourveld, Eastern Valley Bushveld and KwaZulu-Natal Coastal Belt) were extracted from the MODIS products and used as a basis to establish three parameters: annual burnt areas, fre season and fre frequency. The total burnt area within each vegetation type over the 10-year period was quantifed. Results: The KZN Sandstone Sourveld had a high-burnt area of 80% in 2009 with KwaZuluNatal Coastal Belt having the least burnt area of less than 5%. Ngongoni Veld and the KwaZuluNatal Sandstone Sourveld had the highest fre frequency, while the coastal region had low fre frequencies. Results showed high fre prevalence during the late period of the dry season (which extends from June to August) across all the vegetation types. Conclusion: This study underscores the potential of remotely sensed data (MODIS burned area products) in providing a comprehensive view of fre patterns in different vegetation types.