Dense planting means the canopy can prevent rain getting to the ground and the trees take a lot of the water that does get to the ground which means aquifers are not replenished.
The dry ground and dry trees pose an increased fire risk. Burning the tree releases any captured carbon, and a bunch of smoke.
New forests crowd out and change existing eco systems, meaning many animals are lost to the area.
I highly doubt temperate or even tropical forest canopies will prevent water from reaching ground level. Gravity does not work that way.
Trees shade soil reducing evaporation levels. Trees also significantly reduce surface winds further reducing evaporation. Yes trees do potentially use more water which is exactly what you want, what is the purpose of full aquifers flowing into the sea ?
In Australia removal of trees has lead to increased salinity levels affecting 2 Million hectares (In WA alone) of arable land degrading vast swathes of it rendering it unusable for both modern agriculture and pre-agricultural "natural" use. This is precisely because the trees kept the high-salinity water table below surface root levels.
Dense planting means the canopy can prevent rain getting to the ground and the trees take a lot of the water that does get to the ground which means aquifers are not replenished.
The dry ground and dry trees pose an increased fire risk. Burning the tree releases any captured carbon, and a bunch of smoke.
New forests crowd out and change existing eco systems, meaning many animals are lost to the area.