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acts as a trigger component that is required for condensation and precipitation to occur (Millán, 2014a).
               Evapotranspiration has thus been shown to be the most important mechanism in sustaining rainfall over land
               surfaces (Savenije, 1996), due to the cascading effects of moisture moving inland (Schaefli et al., 2012). The
               loss of evapotranspiration through land degradation is thus a direct threat towards the establishment of
               predictable rainfall in many regions.

               Terrestrial  moisture  recycling  is  an  important  concept  that  refers  to  the  process  by  which  moisture
               evaporates from land and returns to land surfaces via precipitation. It has been found that 70% of terrestrial
               precipitation  from  26  of  the  world’s  largest  river  basins  comes  from  evaporation  over  land  through
               atmospheric moisture recycling (Tuinenburg et al., 2020). On average, a drop of water that evaporates into
               the atmosphere from the ocean rains out 2.6 times over land before returning to the ocean via river flow
               (van  Noordwijk  & Ellison,  2019).  Land  degradation may  thus  have  more  profound  consequences  in  the
               decrease in terrestrial rainfall than has been previously understood (Savenije, 1995). Studies of regreening
               arid or semi-arid areas show that the albedo and roughness mechanisms are dominated by the moisture
               recycling  feedback  mechanism on seasonal  and  interannual  time  scales  (Yu  et  al., 2017). The  clear  link
               between  terrestrial  evaporation  and  terrestrial  rainfall  strikes  the  compelling  conclusion  that  terrestrial
               precipitation is a modifiable quantity through land cover change - for better or for worse.

               3.3  Afforestation to enhance terrestrial precipitation

               In the context of afforestation, increased plant water availability through enhanced precipitation is crucial
               for the sustainability of regreening efforts (Huang et al., 2022; Teuling et al., 2019; Wang et al., 2021) and
               critical to justify investments and design a credible resource management structure. Several recent studies
               have explored the changes in the atmospheric water cycle following the large-scale afforestation of the Loess
               Plateau in China completed in 1999 – results show enhanced evapotranspiration (Shao et al., 2019; Tian et
               al., 2022; Zhang et al., 2022) as well as enhanced local precipitation (Shao et al., 2019; Tian et al., 2022; Wang
               et al., 2021; Zhang et al., 2021, 2022). Although an increase in evaporation could imply a decrease in water
               yield (precipitation minus evapotranspiration), studies show that the vegetation rather strengthens the local
               moisture recycling (also known as the precipitation recycling ratio) (Shao et al., 2019; Tian et al., 2022; Wang
               et al., 2021). Tian et al. (2022) revealed that the increased vegetation cover has led to a 20.25% increase in
               precipitation as a result of an overall increase in the humidity of the local atmosphere (+8.49%), heightened
               soil moisture-vegetation-precipitation feedback (the spatial pattern of soil-moisture increase matches that
               of precipitation), stronger moisture convergence (+28.26%), and more cloud formation (+8.28%) (Tian et al.,
               Although previous afforestation efforts have provided great insight on the role of vegetation in governing
               weather  and  climate  in  those  circumstances,  there  are  still  important  knowledge  gaps  with  respect  to
               understanding the local and non-local effects of afforestation and how this links to meso- and synoptic-scale
               phenomena (Bosveld et al., 2020). Predicting the wider effects of afforestation, and land cover change in
               general, on the global terrestrial water cycle requires an understanding of the (non-)biological mechanisms
               of moisture transport, a widely discussed topic amongst scientists today. Although there is general consensus
               that vegetation cover plays an important role in the global water cycle (Sheil, 2018), the physical principles
               behind atmospheric motion and moisture transport, including the role of aerosols, the formation of clouds
               and the (bio)physical drivers of wind have, however, proven to be less trivial (Marotzke et al., 2017). The
               biotic pump theory, first introduced by Makarieva & Gorshkov (2007) suggests there is an “evaporative force”
               driving surface winds - induced by changes in atmospheric pressure caused by condensation above forests.
               The theory contradicts the longstanding “traditional” theory in meteorology: that the differential heating of
               the atmosphere is the principle driving force of wind (Bunyard, 2014).

               The physical principles of the biotic pump theory have been a topic of debate amongst scientists (Bunyard,
               2014; Jaramillo et al., 2018; Meesters et al., 2009; Pearce, 2020), and the role of vegetation in generating

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