Trees with a Denser Crown have Lower Water Consumption than Trees with a Sparser Crown

• Trees have many positive effects on the urban environment, but they are also exposed to several stress factors. Water deficit is one of these. Irrigation, structural soils or selecting drought tolerant species are different ways to meet this problem. Another way might be choosing individuals that could reduce water loss due to microclimate differences within the crown. The objective of this study is to address whether different crown densities in single trees may influence the water consumption during days with high atmospheric demand. Two pairs of similar Tilia cordata Mill. ‘Green spire’ with different crown densities, one dense and one sparse, were planted in containers and placed on scales at a paved yard in Alnarp, Sweden, during July and August 2009. Daily weight loss was continuously logged, and measurements of stomatal conductance and stem water potential were performed twice a day. Stomatal conductance was approximately 66% higher (3 mm s-1) in the sparse tree of pair S7:D46 and approximately 20% higher (1 mm s-1) in the sparse tree of pair S52:D21. The dense trees and sparse tree S52 used on average 10.2-10.9 kg water day-1 (1.2-1.4 mm day-1). Sparse tree S7 used on average 13.8 kg water day-1 (2.1 mm day-1). This difference might be caused by different microclimates in the crowns of the sparse and dense trees. Other factors were kept as similar as possible within each pair. The difference in water use was, however, more pronounced in one of the pairs. This could be caused by the different ability for water uptake and transport in the two pairs. The pair with the largest difference in water use had the strongest growth. We conclude that crown density affects water use of a tree in an urban environment; sparse linden trees consume more water than dense.

Ämnesord

LANTBRUKSVETENSKAPER  -- Lantbruksvetenskap, skogsbruk och fiske -- Skogsvetenskap (hsv//swe)

AGRICULTURAL SCIENCES  -- Agriculture, Forestry and Fisheries -- Forest Science (hsv//eng)

Nyckelord

Urban Tree

Tilia Cordata Mill

‘Green spire’

Microclimate

Stomatal conductance

Forestry and Wood Technology

Skog och träteknik

Publikations- och innehållstyp

ref (ämneskategori)

art (ämneskategori)