Waters and forests: from historical controversy to scientific debate

Abstract

This article presents an historical perspective of the controversy concerning the hydrological impact of forests, and shows how a mostly romantic and emotional confrontation finally evolved into a scientific debate. We first analyze the historical evolution of ideas, starting with the views of Pliny the Elder in the first century AD and ending with the debate on the 'Eaux et Forêts' in France in the 19th century. Then, we give an up-to-date overview of the paired-watershed experiments conducted throughout 20th century, and identify some research issues that should help forest hydrology science to move forward in the 21st century. q

Environmental Services Provided from Riparian Forests in the Nordic Countries

“…In this article, we focus on clear cutting and potential subsequent soil scarification for regeneration or planting that are the most common management operations affecting RF. The increased nutrient influx into RF after clear cutting is due to (i) reduced evapotranspiration from the cut area leading to an increase in runoff (Andréassian 2004;Sørensen et al 2009) and an elevated groundwater table in the RF (deeper snow cover and faster melt rate at the cut area further enhance runoff generation during snowmelt); (ii) reduced nutrient uptake by vegetation and increased organic matter decomposition enhancing nutrient leaching; (iii) exposure of soils to surface runoff increasing erosion risk (e.g. Ahtiainen and Huttunen 1999).…”

Effects of Forest Cover Change on Flood Characteristics in the Upper Citarum Watershed

“…river discharge, peak discharge, or annual average flood volume) has become an important research topic, and this is studied by using direct experiment on catchment scale. Generally, these researches (Hibbert 1967;Bosch & Hewlett 1982;Andre´assian 2004;Brown et al 2005) use paired catchment experiments approach. The general conclusion indicate that forest cover reduction (deforestation) will increase water yield, whereas reforestation in opened land will decrease it (Bosch & Hewlett 1982;Andre´assian 2004;Farley et al 2005;Lima et al 2012).…”

“…Generally, these researches (Hibbert 1967;Bosch & Hewlett 1982;Andre´assian 2004;Brown et al 2005) use paired catchment experiments approach. The general conclusion indicate that forest cover reduction (deforestation) will increase water yield, whereas reforestation in opened land will decrease it (Bosch & Hewlett 1982;Andre´assian 2004;Farley et al 2005;Lima et al 2012). The amount of this reduction varies from one experiment to another (Bruijnzeel 2004), and this is caused by a complex interaction among vegetation, climate, and soil (Zhou et al 2010).…”

“…Research have shown that forest harvesting has increased streamflow and rates of snowmelt and generally, such condition will occur in small headwater 2 catchments (< 1 km ). This shows that forest's role and its impact on water yield (including hydrologic cycle) varied and is still debated (Andre´assian 2004;Ellison et al 2012). Based on the weakness, this researches use a single catchment approach to evaluate the impacts of forest reduction on river discharge at large scale catchment (i.e.…”

Avaliação do impacto da substituição de pastagem por eucalipto na recarga de aquífero freático

“…Após apresentar a perspectiva histórica da controvérsia relacionada com o impacto hidrológico das florestas, Andreassian (2004) concluiu, entre outros, que o efeito desse sobre o fluxo mínimo parece bem estabelecido: reflorestamento diminui e o desflorestamento aumenta o fluxo mínimo dos rios, ou seja, os períodos de fluxo em geral são encurtados pelo reflorestamento, o qual pode causar o completo cessar do fluxo no rio. Contudo, note que o impacto do reflorestamento pode mudar ao longo do tempo.…”