Exploring a novel methodology for post impact assessments of chemical accidents on forest ecosystems: With damage, recovery, and resilience aspects of vegetation

Abstract

Chemical accident leads to severe environmental problems, especially threatening the capacity of the ecosystem for ‘sustainability’. Therefore, a systematic response system, that includes performing a spatial and temporal assessment of the overall impacts due to chemical accidents, is urgently required. This study constructed a new methodology that can support the scientific implementation of post impact assessment through quantitatively assessing damaging impact and recovery endpoints for vegetation subjected to chemical accidents from both spatial and temporal aspects. Through applying a novel index ΔVI (Damage Assessment Factor), vegetation impact was quantitatively assessed. Afterward, with ΔVI applied as a chemical accident impact variable, MaxEnt was used for vegetation recovery assessment. With the change of potential habitat per each scenario, the recovery endpoint was quantitatively derived using the newly developed index, VRI (Vegetation Recovery Index). The results indicated a tendency of damaging impact to decline over time, with shortening of damage persistence and rapid recovery endpoints at a further distance from the accident site, by each spatial zone (R1-R5) in each distance range (0–1000 m). Further, vegetation resilience was analyzed based on the temporal difference between damaging impact and recovery tendency, using the newly developed index, VRCI (Vegetation Resilience Capacity Index). The forest that lacks diversity in functions·species compositions due to fragmentation and narrow areas showed low resilience, and it was spatially·quantitatively analyzed through the landscape fragmentation model (ArcGIS 10.3). This study is expected to be applied as a basis for implementing systematic post management and policies of vegetation in chemical accidents.