H2o and Nutrient Transport: Potassium allows regulate h2o uptake and decline in vegetation by managing the opening and shutting of stomata, the pores on leaves by which gases and h2o vapor are exchanged.?? ?????? ????? ??? ????? ???????? ?????? ??????? ?????? ???????? ???????? ???? ????? ?????? ?? ???????.????????? ??????? ?? ??? ?????? ???? ?? ???