protected areas (pAs) are a foundational and essential strategy for reducing biodiversity loss. However, many pAs around the world exist on paper only; thus, while logging and habitat conversion may be banned in these areas, illegal activities often continue to cause alarming habitat destruction. in such cases, the presence of armed conflict may ultimately prevent incursions to a greater extent than the absence of conflict. Although there are several reports of habitat destruction following cessation of conflict, there has never been a systematic and quantitative "before-and-after-conflict" analysis of a large sample of pAs and surrounding areas. Here we report the results of such a study in colombia, using an open-access global forest change dataset. By analysing 39 PAs over three years before and after colombia's peace agreement with the Revolutionary Armed forces of colombia (fARc), we found a dramatic and highly significant increase in the deforestation rate for the majority of these areas and their buffer zones. We discuss the reasons behind such findings from the Colombian case, and debate some general conservation lessons applicable to other countries undergoing post-conflict transitions. The growing warfare ecology literature reports both negative and positive effects of conflict for biodiversity and the natural environment 1-3. This also applies to deforestation, which can be either increased or decreased depending on the specific complex socio-ecological dynamics linked to the conflict itself 3-5. Increased deforestation during conflict is reported for several regions of the world 6 , including Democratic Republic of Congo (DRC) and Liberia 7 or Myanmar and Cambodia 8. In some cases, conflict reduces the institutional capacity to enforce laws and effectively manage the use or protection of natural resources, e.g. as reported for Kenya 9 , DRC 10 , Nepal 11 , and Colombia 5. In other cases, the displacement of people escaping or forced to leave conflict areas, the basic mechanism for the 'refuge effect' 12 , can prove beneficial for habitat and biodiversity protection, e.g. by limiting the pressure of resource extraction 13-15. The demilitarized Zone between North and South Korea is a good example of such a refuge 16. Conflict can largely disrupt economic activities 1 , such as timber logging in Nicaragua 17 , or farming, as in Sierra Leone 18. In the Chechen wars and in the nearby Nagorno-Karabakh conflict, agricultural land was abandoned in warzones, along with reported low re-cultivation rates after the cessation of the conflict 19,20. In other cases post-conflict development results in higher threats to forested ecosystems than conflict

Conservation interventions such as assisted migration and genetic alterations are controversial in part because, through unintended hybridization events, they may imperil native species. Threats could stem from hybrid offspring having altered fitness or from genetic swamping due to extensive introgression of non‐native genes. Over the last 40 years, papers discussing hybridization increasingly use value‐laden terminology (e.g., “genetic contamination”). Such terms presume that any amount of hybridization equates to harm, but this perspective is at odds with modern evolutionary theory's recognition of hybridization as a creative force that can accelerate evolution or spur adaptive breakthroughs. To assess the evidence undergirding perceptions of hybridization threats, we examined the IUCN's Global Invasive Species Database (GISD). Of 870 invasive species, the GISD identified 35 as potentially threatening endemic taxa via hybridization. For each of these 35 species, we assessed the quality of data that the GISD cited pertaining to hybridization. Direct evidence for hybridization was cited for only 16 species, and there was neither direct nor indirect evidence demonstrating reduced fitness of hybrid offspring for 18 species. In our era of rapid environmental change, it is time to examine hybridization case‐by‐case and not to presume that hybridization always presents a threat to biodiversity, but rather, to consider it as a potential pathway to species survival.

Rooftops provide accessible locations for solar energy installations. While rooftop solar arrays can offset inbuilding electricity needs, they may also stress electric grid operations. Here we present an analysis of net electricity generation potential from distributed rooftop solar in Los Angeles. We integrate spatial and temporal data for property-level electricity demands, rooftop solar generation potential, and grid capacity constraints to estimate the potential for solar to meet on-site demands and supply net exports to the electric grid. In the study area with 1.2 million parcels, rooftop solar could meet 7200 Gigawatt Hours (GWh) of on-site building demands (~29% of demand). Overall potential net generation is negative, meaning buildings use more electricity than they can produce. Yet, cumulative net export potential from solar to grid circuits is 16,400 GWh. Current policies that regulate solar array interconnection to the grid result in unutilized solar power output of 1700 MW. Lowerincome and at-risk communities in LA have greater potential for exporting net solar generation to the grid. This potential should be recognized through investments and policy innovations. The method demonstrates the need for considering time-dependent calculations of net solar potential and offers a template for distributed renewable energy planning in cities.