Impacts of winter feeding of reindeer on vegetation and soil in the sub-Arctic: insights from a feeding experiment

The overall impacts of winter feeding, including the effects of both forage and reindeer (Rangifer tarandus), were studied in an experiment in the Hammastunturi herding cooperative (68°N), Finland, with 300 reindeer in a sub-xeric heath forest (35 ha) during March/April 2009 and 2010. The feeding practices on the 50 plots were: (1) feeding with grass silage+hay with leftovers cleared in the spring; (2) feeding with grass silage+hay with leftovers not cleared; and (3) feeding with pellets. In addition, (4) unfenced and (5) fenced control plots were included, on which the reindeer were not fed. No invasive plant species introduced through grass silage+hay were observed on the plots. The coverage of Deschampsia flexuosa increased on grass silage+hay plots after the first winter, and both coverage and height of the grass increased after the second winter. The coverage of Dicranum sp. and Pleurozium schreberi was lower on plots where reindeer were fed with grass silage (leftover silage not cleared) vs. controls. Some dwarf shrubs, e.g., Calluna vulgaris, showed a similar response after the second winter. The N content of Empetrum nigrum was higher on grass silage plots (leftover silage not cleared) after the first winter vs. controls. After two winters, the N content of both E. nigrum and Vaccinium myrtillus was increased. Of the soil variables studied, C/N decreased on grass silage+hay plots vs. fenced controls. We conclude that even a moderate level of feeding may cause changes that can lead to a gradual shift from nutrient-poor heath forest towards a more nutrient-rich type

The Cost of Extreme Heat: A Cost/Benefit Analysis of Three Heat-Ameliorating Interventions in Portland, Oregon

The detrimental, sometimes fatal effects of urban heat are well documented, and it is generally accepted that extreme heat poses a threat to human health and quality of life. Less understood is the financial impact of heat, including such factors as energy consumption, health care expenses, and the economic loss associated with premature death. This analysis examines several potential cost factors associated with extreme heat, as well as the potential savings offered by three heat-ameliorating interventions: eco roof installation, road lightening, and street tree planting. The cost of each intervention is assessed based on the best available data, and compared to the expected financial benefits for Portland, Oregon, with focus given to the hottest, most exposed census block groups (CBGs) One extreme heat event can cause billions of dollars of damage in health costs alone (premature death, emergency room visits, treatment of illness). This analysis shows that any/all of the three proposed interventions (which cost anywhere from $17-160 million each to implement in the hottest CBGs) are well worth the price, and that the cost-saving benefits far outweigh the implementation costs. Furthermore, street trees have the added financial benefit of increasing property values and property tax revenue. Results strongly indicate that heat-ameliorating interventions are a smart investment for the City of Portland, particularly as climate change causes more frequent and severe urban heat waves