Plant community composition and interspecific relationships among dominant species on a post-seismic landslide in Hongchun Gully, China

The 5.12 Earthquake in 2008 and 8.14 Debris Flow in 2010 resulted in large-scale landslides that disturbed vast areas of vegetation in the Hongchun Gully, Wenchuan County, China. To define the specific characteristics of vegetation restoration during natural recovery after catastrophic events,vegetation species composition and interspecific associations were investigated on this typical landslide. Field survey data selected from a total of 51 sample plots belonged to seven belt transects and were analysed by Schluter's variance ratio, pearson's chi-squared test, Spearman's correlation coefficients and ecological species groups. Plant communities on the landslide consisted of 78 species, 65 genera and52 families. Of the total of 78 species, 25 are identified as dominant species, among which Camptotheca acuminate, Toxicodendron vernicifluum, Coriaria nepalensis, Robinia pseudoacacia, Buddleja alternifolia, Anemone vitifolia and Nephrolepis auriculata play a constructive role during the natural afforestation. Moreover, according to environmental and ecological factors, these 25 dominant species could be divided into four ecological species groups.This study found that even though the landslide had frequently suffered from interference due to heavy rain, the vegetation succession processes are ongoing,and it is now at a shrub–herb community succession stage, which indicates that vegetation can naturally recover in the denuded sites. This study provides a useful insight into the ecological interactions and interdependence between plant species during the natural recovery of vegetation and provides valuable information on vegetation recovery modelling in the landslide area.

Untangling the relationship between power outage and population activity recovery in disasters

Despite recognition of the relationship between infrastructure resilience and community recovery,very limited empirical evidence exists regarding the extent to which the disruptions in and restoration of infrastructure ser-vices contribute to the speed of community recovery.To address this gap,this study investigates the relationship between community and infrastructure systems in the context of hurricane impacts,focusing on the recovery dy-namics of population activity and power infrastructure restoration.Empirical observational data were utilized to analyze the extent of impact,recovery duration,and recovery types of both systems in the aftermath of Hurricane Ida.The study reveals three key findings.First,power outage duration positively correlates with outage extent until a certain impact threshold is reached.Beyond this threshold,restoration time remains relatively stable re-gardless of outage magnitude.This finding underscores the need to strengthen power infrastructure,particularly in extreme weather conditions,to minimize outage restoration time.Second,power was fully restored in 70% of affected areas before population activity levels normalized.This finding suggests the role infrastructure function-ality plays in post-disaster community recovery.Quicker power restoration did not equate to rapid population activity recovery due to other possible factors such as transportation,housing damage,and business interruptions.Finally,if power outages last beyond two weeks,community activity resumes before complete power restoration,indicating adaptability in prolonged outage scenarios.This implies the capacity of communities to adapt to on-going power outages and continue daily life activities.These findings offer valuable empirical insights into the interaction between human activities and infrastructure systems,such as power outages,during extreme weather events.They also enhance our empirical understanding of how infrastructure resilience influences community recovery.By identifying the critical thresholds for power outage functionality and duration that affect popula-tion activity recovery,this study furthers our understanding of how infrastructure performance intertwines with community functioning in extreme weather conditions.Hence,the findings can inform infrastructure operators,emergency managers,and public officials about the significance of resilient infrastructure in life activity recovery of communities when facing extreme weather hazards.