Search

After affecting millions of hectares of pine forests in western Canada, the mountain pine beetle (MPB; Dendroctonous ponderosae Hopkins) is spreading out of its native range and into Canada's boreal forest. Impacts of outbreaks can be environmental, economic, and social, and an ecosystem services (ES) viewpoint provides a useful perspective for an integrated approach to assessing these impacts and may help to identify how possible management strategies could minimize these impacts. In this regards, a comprehensive overview of the ecosystem functions and socioeconomic factors that have been impacted by the current outbreaks in western Canada was carried out to facilitate a more general ES assessment. In addition to timber production, current MPB outbreaks have negative effects on provisioning services (water supply and food production) and aesthetic cultural services, while effects on regulating services (carbon and forest fire) are still in debate. Among the supporting services, nutrient cycling and aquatic habitat showed short- and long-term negative effects, while terrestrial habitat showed a mostly positive response. The overall impact on ES may be more severe if salvage logging is practiced as a post-MPB forest management strategy. The outcomes of this study may help to identify areas of greatest socioecological vulnerability to MPB and identify knowledge gaps and avenues for research to advance the ES framework for MPB outbreak management. Key words: ecosystem function, lodgepole pine, provisioning services, regulating services, salvage logging. Apres avoir devaste des millions d'hectares de foret de pin dans l'ouest du Canada, le dendroctone du pin ponderosa (DPP) se repand a l'exterieur de son aire de repartition indigene dans la foret boreale canadienne. Les impacts des epidemies peuvent etre environnementaux, economiques et sociaux et l'angle des ecoservices (ES) offre une perspective utile pour une approche integree de revaluation de ces impacts et peut aussi bien aider a identifier comment des strategies potentielles d'amenagement pourraient minimiser ces impacts. A cet egard, une synthese complete des fonctions de l'ecosysteme et des facteurs socio-economiques qui ont subi l'impact des epidemies en cours dans l'ouest du Canada a ete effectuee pour faciliter une evaluation plus generale des ES. En plus de la production de matiere ligneuse, les epidemies actuelles du DPP ont des effets negatifs sur les services d'approvisionnement (alimentation en eau et production de nourriture) et les services esthetiques et culturels, tandis que les effets sur les services de regulation (carbone et feux de foret) sont encore controverses. Parmi les services de support, le recyclage des nutriments et l'habitat aquatique ont subi des effets negatifs a court et long terme tandis que l'habitat terrestre a surtout reagi positivement. L'impact global sur les ES pourrait etre plus severe si la coupe de recuperation est utilisee comme strategie d'amenagement forestier apres le passage du DPP. Les resultats de cette etude peuvent aider a identifier les zones de plus grande vulnerabilite socio-ecologique au DPP ainsi qu'a identifier les lacunes dans les connaissances et les avenues de recherche visant a ameliorer le cadre des ES pour la gestion des epidemies du DPP. [Traduit par la Redaction] Mots-cles: fonction de l'ecosysteme, pin ponderosa, services d'approvisionnement, services de regulation, coupe de recuperation., 1. Introduction Outbreaks of mountain pine beetle (MPB; Dendroctonous ponderosae Hopkins) are natural phenomena that play a critical role in the development of western North American pine forests (Safranyik and [...]

We evaluated the uncertainty associated with secondary pollutants formation due to different chemical mechanisms in photochemical modelling. The CMAQ modelling system was utilized in conjunction with CB6R3, SAPRC07, and RACM2 chemical mechanisms and compared the concentrations of various chemical species, including ozone (O3) and particulate matter (PM2.5). Using datasets from ambient monitoring stations, we assessed the performance of each of the mechanism in summer and winter. The concentrations of various chemical species predicted by the three mechanisms varied significantly. The differences are more evident in summer than in winter for most of the species, except for hydrogen peroxide (H2O2), methyl hydroperoxide (MEPX), and Secondary Organic Aerosol—Anthropogenic. We observed that the summer daytime O3 predictions showed reasonable peaks at the three air quality monitoring sites, but the nighttime values under-predicted for all three mechanisms. In the winter, all three mechanisms tend to under-predict O3. Differences in the mean O3 values (bias) at the different sites, for the different seasons, are consistent with corrections made to previous modelling studies that modified KZMIN. PM2.5 predictions with RACM2 were slightly better. The dominant PM2.5 species in summer were sulfate and SOA-Bio, which may be attributed to non-mobile sources in the region, while NO3 became dominant in winter due to more favorable conditions for forming this species, including lower temperatures and an elevated NH4 to SO4 ratio. We concluded that the differences in O3 and PM2.5 predictions between the three mechanisms are significant, implying that when developing strategic and management actions are based on modelling, the most appropriate mechanism should be considered. [ABSTRACT FROM AUTHOR]

The article offers information on the West Arnhem Land Fire Abatement (WALFA) project in Northern Territory. It mentions that Indigenous rangers use prescribed burns throughout the 28,000 square kilometers of Indigenous-owned land on the Arnhem Land plateau to increase vegetation patchiness and make firebreaks. It states that renewed fire management on the plateau has been approximated to lessen emissions by about 147,000 metric tons every year.

This paper presents results from the MayaSim model, an integrated agent-based, cellular automata, and network model representing the ancient Maya social-ecological system. The model represents the relationship between population growth, agricultural production, soil degradation, climate variability, primary productivity, hydrology, ecosystem services, forest succession, and the stability of trade networks. Agents representing settlements develop and expand within a spatial landscape that changes under climate variation and responds to anthropogenic impacts. The model is able to reproduce spatial patterns and timelines somewhat analogous to that of the ancient Maya, although this proof-of-concept model requires refinement and further archaeological data for calibration. This paper aims to identify candidate features of a resilient versus vulnerable social-ecological system, and employs computer simulation to explore this topic, using the ancient Maya as an example. Complex systems modelling identifies how interconnected variables behave, considering fast-moving variables such as land cover change and trade connections, meso-speed variables such as demographics and climate variability, as well as slow-moving variables such as soil degradation. [ABSTRACT FROM AUTHOR]