\u201cInvasive alien trees have higher transpiration rates, compared to the native vegetation of the Cape mountains, and thus reduce streamflow,\u201d Holden explained.<\/p>\n
The research team combined climate models and a hydrological model to simulate streamflow during the \u2018Day Zero\u2019 drought. Following this, they tested how severe the hydrological drought would have been if there had been no human-driven climate change. For this, their focus was specifically on the impacts of climate change and alien tree management on streamflow from mountainous catchments that supply dams critical for water supply to Cape Town.<\/p>\n Holden explained: \u201cExisting studies do not isolate the effect of nature-based solutions on the anthropogenically derived (i.e., human-derived) portion of climate change, especially for drought events that have already occurred. Few studies attribute biophysical impacts to human-caused climate change impact on drought events while simultaneously investigating the role of nature-based solutions in modulating this impact.\u201d<\/p>\n This new analysis indicates that climate change reduced streamflow during the drought by 12% to 29% relative to a world without human-influence on the climate. Furthermore, it shows that clearing alien trees that were present in the catchments before the drought hit could have reduced the anthropogenic climate change impact on streamflow, but the effect was dependent on the extent of invasion.<\/p>\n Clearing moderate levels of invasion (such as 40% coverages seen in some catchments) would have resulted in a 3% to 16% amelioration of the human-derived climate change impact on streamflow. Preventing the spread of alien trees from current levels to full catchment invasion avoided additional reductions of 10% to 27% in streamflow due to anthropogenic climate change.<\/p>\n The researchers also discovered that the impact of climate change was amplified due to catchment hydrological processes. For example, the reductions in streamflow (12% to 29%) were larger than the reductions in rainfall caused by anthropogenic climate change (7% to 15%). Despite the role that evapotranspiration can play in drought events, the researchers did not uncover a large impact of climate change due to evapotranspiration.<\/p>\n This is an important study for highlighting the power of quantitative assessments to inform climate change adaptation planning. The researchers were able to demonstrate that catchment restoration reduced the impact of anthropogenic climate change, but was not able to remove the full signal of human-driven climate change completely, even under current levels of climate warming.<\/p>\n Given this, the researchers stressed that it is critical to combine nature-based solutions with other adaptation strategies and options for water resource planning to combat accelerated climate change impacts.<\/p>\n \u201cTeasing out the contribution of adaptation strategies \u2013 be they nature-based or not \u2013 for buffering society from human-driven versus natural variability in climate can be challenging. However, it is important to inform adaptation planning so that climate risk management strategies can be combined in ways that consider thresholds and limits to change,\u201d concluded Holden.<\/p>\n","protected":false},"excerpt":{"rendered":" A new research study highlights that catchment restoration can reduce the impact of human-driven climate change in mountainous regions. New research, led by Dr Petra Holden from the African Climate and Development Initiative (ACDI) at the University of Cape Town (UCT), has shown how catchment restoration \u2013 through the management of alien tree infestation in […]<\/p>\n","protected":false},"author":19,"featured_media":19294,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_monsterinsights_skip_tracking":false,"_monsterinsights_sitenote_active":false,"_monsterinsights_sitenote_note":"","_monsterinsights_sitenote_category":0,"footnotes":""},"categories":[24433,785],"tags":[689,789,758],"acf":[],"yoast_head":"\n![\"catchment](\"https:\/\/www.innovationnewsnetwork.com\/wp-content\/uploads\/2022\/03\/Low-Res_Recently-cleared-areas-of-invasive-alien-trees-from-the-Cape-Mountains_Credit_Cape-Winelands-Biosphere-Reserve.JPG-300x225.png\")
\u2018Day Zero\u2019 drought<\/h3>\n
Climate change impact<\/h3>\n