Tropical peat swamp forests (PSFs) play a significant role in the exchange of water between land and the atmosphere. However, fire and drainage have been expanding in PSFs in recent decades. Although there is concern on the influence of fire and drainage on water circulation, their influence on evapotranspiration (ET) is insufficiently understood. Furthermore, repeated fire occurrences and their corresponding influence on the ET by recurrent burning and smoldering is unexplored. To elucidate these influences, we examined long-term variation of ET in a degraded peat swamp forest in Central Kalimantan, Indonesia that was affected by drainage and repeated fire. The continuous observation of energy fluxes was conducted for approximately 13 years between 2004 and 2016 by using the eddy covariance technique. The site burned in 2009 and 2014, and was drained in 2014. Monthly ET and net radiation (R_n) fluctuated in synchrony and thus they decreased considerably under fire-induced dense haze during the El Niño drought. Troughs of ET, groundwater level (GWL) and R_n and crests of vapor pressure deficit (VPD) coincided in their time-series variations. In the case of ET > precipitation (P), ET decreased when the GWL was deeper than −0.5 m. Half-hourly ET had a strong positive correlation with R_n (R = 0.89, p < 0.01), and partial positive relationship with VPD when VPD < 20 hPa and with GWL when GWL < -0.5 m. ET had no correlation with the Enhanced Vegetation Index (EVI), which represents above ground biomass for the entire observation period. Alternately, the results of path analysis showed that some environmental factors controlled ET differently depending on environmental conditions. Generally, VPD negatively affected ET due to stomatal regulation functions under dry atmospheric conditions. However, the effect was negligible during the water-logged periods. This is because atmospheric dryness facilitated evaporation from exposed water on the ground surface, which canceled out the negative effect of transpiration due to stomatal closure. After drainage by canal excavation, fluctuation of GWL did not significantly influence ET, although ET decreased. This may be due to the hydrophobic dried peat soil, which prevents rainwater infiltration, disconnection of capillary force, or disabled root water uptake as GWL excessively deepened. Fire potentially decreased ET due to decreased transpiration by burning of vegetation. However, the decreasing effect was cancelled by increased evaporation from the waterlogged ground surface during the subsequent La Niña event. Drainage undoubtedly deepened the GWL, and ET severely decreased in cases with extremely deep GWL.

热带泥炭沼泽森林 (PSF) 在陆地和大气之间的水交换中发挥着重要作用。然而，近几十年来，PSF 中的消防和排水系统一直在扩大。尽管人们担心火和排水对水循环的影响，但对它们对蒸散量 (ET) 的影响了解不够。此外，还没有探索反复发生的火灾及其对 ET 的反复燃烧和阴燃的相应影响。为了阐明这些影响，我们研究了印度尼西亚加里曼丹中部受排水和反复火灾影响的退化泥炭沼泽森林中 ET 的长期变化。在 2004 年至 2016 年期间，使用涡流协方差技术对能量通量进行了连续观测，持续了大约 13 年。该网站在 2009 年和 2014 年被烧毁，R _n ) 同步波动，因此在厄尔尼诺干旱期间，它们在火灾引起的浓雾下显着下降。ET，地下水位（GWL）和波谷ř _Ñ和水气压差（VPD）的波峰正好在它们的时间序列的变化。在 ET > 降水 ( P )的情况下，当 GWL 深于 -0.5 m 时，ET 减少。半小时ET有具有较强的正相关性[R _Ñ（[R  = 0.89，p < 0.01)，当 VPD < 20 hPa 时与 VPD 部分正相关，当 GWL < -0.5 m 时与 GWL 部分正相关。ET 与增强植被指数 (EVI) 没有相关性，EVI 代表整个观测期间的地上生物量。或者，路径分析的结果表明，一些环境因素根据环境条件对 ET 的控制不同。通常，由于干燥大气条件下的气孔调节功能，VPD 会对 ET 产生负面影响。然而，在积水期间，影响可以忽略不计。这是因为大气干燥促进了地表暴露水的蒸发，抵消了气孔关闭造成的蒸腾作用。开挖引流后，GWL的波动对ET无显着影响，虽然 ET 减少了。这可能是由于疏水性干泥炭土阻止了雨水的渗透、毛细管力的断开，或者当 GWL 过度加深时，根部吸水能力下降。由于燃烧植被减少蒸腾作用，火灾可能会降低 ET。然而，在随后的拉尼娜事件期间，水淹地表的蒸发量增加，抵消了下降的影响。引流无疑加深了 GWL，在极深 GWL 的情况下，ET 严重下降。在随后的拉尼娜事件期间，水淹地表的蒸发量增加，抵消了下降的影响。引流无疑加深了 GWL，在极深 GWL 的情况下，ET 严重下降。在随后的拉尼娜事件期间，水淹地表的蒸发量增加，抵消了下降的影响。引流无疑加深了 GWL，在极深 GWL 的情况下，ET 严重下降。