Deforestation and climate change are interconnected and represent major environmental challenges. Here, we explore the capacity of regional-scale restoration of marginal agricultural lands to savanna woodlands in Australia to reduce warming and drying resulting from increased concentration of greenhouse gases. We show that restoration triggers a positive feedback loop between the land surface and the atmosphere, characterised by increased evaporative fraction, eddy dissipation and turbulent mixing in the boundary-layer resulting in enhanced cloud formation and precipitation over the restored regions. The increased evapotranspiration results from the capacity deep-rooted woody vegetation to access soil moisture. As a consequence, the increase in precipitation provides additional moisture to soil and trees, thus reinforcing the positive feedback loop. Restoration reduced the rate of warming and drying under the transient increase in the radiative forcing of greenhouse gas emissions (RCP8.5). At the continental scale, average summer warming for all land areas was reduced by 0.18 oC from 4.1 oC for the period 2056–2075 compared to 1986–2005. For the restored regions (representing 20% of Australia), the averaged surface temperature increase was 3.2 °C which is 0.82 °C cooler compared to agricultural landscapes. Further, there was reduction of 12% in the summer drying of the near-surface soil for the restored regions.
展开▼
机译：森林砍伐和气候变化是相互联系的，并代表着重大的环境挑战。在这里，我们探讨了在澳大利亚对稀树草原林地进行边际农业用地的区域规模恢复的能力，以减少由于温室气体浓度增加而导致的变暖和干燥。我们表明，恢复会触发陆地表面和大气之间的正反馈回路，其特征在于边界层中蒸发分数，涡流消散和湍流混合增加，从而导致恢复区的云形成和降水增加。蒸散量的增加是由于根深蒂固的木本植物吸收土壤水分的能力所致。结果，降水的增加为土壤和树木提供了额外的水分，从而增强了正反馈回路。在温室气体排放的辐射强迫短暂增加的情况下，恢复降低了升温和干燥的速度（RCP8.5）。在大陆范围内，与1986-2005年相比，2056-2075年期间所有土地区域的夏季平均升温均比4.1 o o降低了0.18 supooC。对于恢复的地区（占澳大利亚的20％），平均地表温度升高了3.2°C，比农业景观低了0.82°C。此外，恢复区域的近表层土壤夏季干燥减少了12％。
展开▼
