Global increases in intensive forestry have raised concerns about forest plantation effects on water, but few studies have tested the effects of plantation forest removal and native forest restoration on catchment hydrology. We describe results of a 14-year paired watershed experiment on ecological restoration in south central Chile which documents streamflow response to the early stages of native forest restoration, after clearcutting of plantations of exotic fast-growing Eucalyptus, planting of native trees, and fostering natural regeneration of native temperate rainforest species. Precipitation, streamflow, and vegetation were measured starting in 2006 in four small (3 to 5 ha) catchments with Eucalyptus globulus plantations and native riparian buffers in the Valdivian Coastal Reserve. Mean annual precipitation is 2500 mm, of which 11% occurs in summer. Streamflow increased, and increases persisted, throughout the first 9 years of vigorous native forest regeneration (2011 to 2019). Annual streamflow increased by 40% to >100% in most years and >150% in fall and summer of some years. Streamflow was 50% to 100% lower than before treatment in two dry summers. Base flow increased by 28% to 87% during the restoration period compared to pre-treatment, and remained elevated in later years despite low summer precipitation. Overall, these findings indicate that removal of Eucalyptus plantations immediately increased streamflow, and native forest restoration gradually restored deep soil moisture reservoirs that sustain base flow during dry periods, increasing water ecosystem services. To our knowledge this is the first study to assess catchment streamflow response to native forest restoration in former forest plantations. Therefore, the results of this study are relevant to global efforts to restore native forest ecosystems on land currently intensively managed with fast-growing forest plantations and may inform policy and decision-making in areas experiencing a drying trend associated with climate change.
The calculation of the fuel consumption, fuel economy and carbon dioxide emissions (CO
2) of a heavy-duty vehicle is detailed. First the forces over a vehicle in motion are calculated and then the necessary torque and the revolutions per minute (rpm) of the engine to provide the tractive force are found. The fuel consumption in kilograms per second for a pair of rpm and torque is obtained from the engine fuel map. The CO
2 emissions are obtained from the fuel consumption. The maxima of the torque and power of a 455 horse power engine are presented as a function of the rpm as well as the specific fuel consumption of the vehicle at the maxima values of the torque. Finally, the fuel economy of the vehicle moving in part of one of the cycles used by the Environmental Protection Agency of the United States of America to certify heavy-duty vehicles to fuel consumption and CO
2 emissions is calculated.
The fuel economy and carbon dioxide emissions (CO
2) of a heavy duty pickup moving in a driving cycle is calculated using the sofware UAMmero. The driving cycle consists of three parts: in the first part the vehicle is simulated to travel in an urban region in which the speed changes constantly, in the second part the simulated vehicle travels in a highway with a cruise speed of 88.514 kilometers/hour and in the third part the simulated vehicle travels at a cruise speed of 104.607 kilometers per hour. Results for the fuel economy and CO
2 emissions for a 4.407 ton, six gear transmission, 200 horse power diesel engine heavy Duty pickup are presented for different masses of the loads and slopes of the road. These results are part of a study to propose a method to certify heavy duty vehicles for fuel economy and CO
2 emissions in Mexico.
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