Although several studies have assessed the effects of thinning on water quality,including nitrogen(N)exports,few have examined N-saturated plantations.This study assessed the short-term effect of thinning on N exports...Although several studies have assessed the effects of thinning on water quality,including nitrogen(N)exports,few have examined N-saturated plantations.This study assessed the short-term effect of thinning on N exports from a N-saturated plantation forest in northern Kyushu,western Japan,that was thinned(43%of basal area)during January-March 2012.Water levels at the gauging station were continually measured,and streamwater baseflow and stormflow samples were collected before(2011)and after(2013)forest thinning.Annual precipitation before(2469 mm)and after(2418 mm)forest thinning differed little,and annual water discharge after thinning(1641 mm)was similar to that before thinning(1609 mm).However,direct flow during stormflow periods was higher after thinning(260 mm)than before(153 mm).The concentrations of major ions in stream water did not differ before and after thinning.As a result,the high annual dissolved inorganic N(DIN)exports differed little before(35.8 kg N ha^-1 a^-1)and after(36.5 kg N ha^-1 a^-1)forest thinning.DIN exports during stormflow periods were slightly higher after(12.2 kg N ha^-1 a^-1)than before thinning(10.5 kg N ha^-1 a^-1)and were proportional to the increased direct flow after thinning(561 mm after vs.470 mm before thinning).We concluded that thinning does not affect annual N exports from the N-saturated plantation forest,but it can increase the proportion of N exported during stormflow periods in proportion to increased water volume of direct flow after thinning.展开更多
Globally,forests play a critical role in regulating the hydrological cycle,supplying water to ecosystems and people.However,both forests and this cycle are undergoing rapid changes[1],[2].Future states of forests and ...Globally,forests play a critical role in regulating the hydrological cycle,supplying water to ecosystems and people.However,both forests and this cycle are undergoing rapid changes[1],[2].Future states of forests and the associated hydrological cycle remain highly uncertain,influenced by altered disturbance regimes such as increasingly frequent and severe wildfires,droughts,and hurricanes,as well as gradual changes such as sea level rise,warming temperatures,and shifts in the amount,seasonal pattern,and form of precipitation[3].Human activities in forested areas compound these changes,potentially intensifying extreme events,such as floods and droughts[1],[2].Consequently,there is an urgent need to manage global forests for ensuring water provision while minimizing associated risks[4].Yet,it remains unclear how the insights from a century of forest-water research can be applied in these emerging contexts.展开更多
文摘Although several studies have assessed the effects of thinning on water quality,including nitrogen(N)exports,few have examined N-saturated plantations.This study assessed the short-term effect of thinning on N exports from a N-saturated plantation forest in northern Kyushu,western Japan,that was thinned(43%of basal area)during January-March 2012.Water levels at the gauging station were continually measured,and streamwater baseflow and stormflow samples were collected before(2011)and after(2013)forest thinning.Annual precipitation before(2469 mm)and after(2418 mm)forest thinning differed little,and annual water discharge after thinning(1641 mm)was similar to that before thinning(1609 mm).However,direct flow during stormflow periods was higher after thinning(260 mm)than before(153 mm).The concentrations of major ions in stream water did not differ before and after thinning.As a result,the high annual dissolved inorganic N(DIN)exports differed little before(35.8 kg N ha^-1 a^-1)and after(36.5 kg N ha^-1 a^-1)forest thinning.DIN exports during stormflow periods were slightly higher after(12.2 kg N ha^-1 a^-1)than before thinning(10.5 kg N ha^-1 a^-1)and were proportional to the increased direct flow after thinning(561 mm after vs.470 mm before thinning).We concluded that thinning does not affect annual N exports from the N-saturated plantation forest,but it can increase the proportion of N exported during stormflow periods in proportion to increased water volume of direct flow after thinning.
文摘Globally,forests play a critical role in regulating the hydrological cycle,supplying water to ecosystems and people.However,both forests and this cycle are undergoing rapid changes[1],[2].Future states of forests and the associated hydrological cycle remain highly uncertain,influenced by altered disturbance regimes such as increasingly frequent and severe wildfires,droughts,and hurricanes,as well as gradual changes such as sea level rise,warming temperatures,and shifts in the amount,seasonal pattern,and form of precipitation[3].Human activities in forested areas compound these changes,potentially intensifying extreme events,such as floods and droughts[1],[2].Consequently,there is an urgent need to manage global forests for ensuring water provision while minimizing associated risks[4].Yet,it remains unclear how the insights from a century of forest-water research can be applied in these emerging contexts.
