There is limited space for new trees, Ms. Bansley said, and with Atlanta in a drought, Trees Atlanta must reserve money to care for planted trees.
The early-season drought trees were re-watered on November 7, December 1, December 26 and January 16, while the late-season drought trees were re-watered on February 20 , March 13 and April 19
There were no significant differences (P > 0.05) in height, diameter and basal area between early- and late-season drought trees at the end of the experiment (Table 2), although total S ψ was larger in the early season drought trees than in the late season drought trees.
Furthermore, the early-season drought trees recovered rapidly after water stress, and even surpassed the well-watered trees for monthly stem height growth.
The well-watered trees showed significantly lower δ13C values over the entire growth period compared with those for the summer drought trees because of higher soil water availability.
At a similar monthly water stress integral, late-season drought trees experienced a greater reduction in monthly stem diameter growth compared with the early-season drought trees, suggesting that late-season drought is more detrimental to tree growth and biomass accumulation in juvenile P. radiata than early-season drought.
In addition, the early-season drought trees rapidly recovered from water stress and exceeded the well-watered treatment for monthly stem height growth, whilst the late-season drought trees remained suppressed through to the end of the experiment and into the new growing season.
Trees exposed to early-season drought between October and January increased in diameter by 5.36 mm during that period compared with 10.60 mm for the late-season drought trees and 10.17 mm for the well-watered trees.
When water deficits were imposed between February and May for the late-season drought trees, their diameter increased by 2.37 mm compared with 8.90 mm for the early-season drought and 9.41 mm for the well-watered treatment trees.
The well-watered trees in this study had over three-fold the total biomass of the summer drought trees and a four-fold difference in branch biomass which exceeded the difference for any other tree components between these treatments.
