Journal Article

Edge type affects leaf-level water relations and estimated transpiration of <i>Eucalyptus arenacea</i>

Thomas E. Wright, Michael Tausz, Sabine Kasel, Liubov Volkova, Andrew Merchant and Lauren T. Bennett

Edited by Nathan Phillips

in Tree Physiology

Volume 32, issue 3, pages 280-293
Published in print March 2012 | ISSN: 0829-318X
Published online February 2012 | e-ISSN: 1758-4469 | DOI: http://dx.doi.org/10.1093/treephys/tps001
Edge type affects leaf-level water relations and estimated transpiration of Eucalyptus arenacea

More Like This

Show all results sharing this subject:

  • Plant Sciences and Forestry

GO

Show Summary Details

Preview

While edge effects on tree water relations are well described for closed forests, they remain under-examined in more open forest types. Similarly, there has been minimal evaluation of the effects of contrasting land uses on the water relations of open forest types in highly fragmented landscapes. We examined edge effects on the water relations and gas exchange of a dominant tree (Eucalyptus arenacea Marginson & Ladiges) in an open forest type (temperate woodland) of south-eastern Australia. Edge effects in replicate woodlands adjoined by cleared agricultural land (pasture edges) were compared with those adjoined by 7- to 9-year-old eucalypt plantation with a 25m fire break (plantation edges). Consistent with studies in closed forest types, edge effects were pronounced at pasture edges where photosynthesis, transpiration and stomatal conductance were greater for edge trees than interior trees (75m into woodlands), and were related to greater light availability and significantly higher branch water potentials at woodland edges than interiors. Nonetheless, gas exchange values were only ∼50% greater for edge than interior trees, compared with ∼200% previously found in closed forest types. In contrast to woodlands adjoined by pasture, gas exchange in winter was significantly lower for edge than interior trees in woodlands adjoined by plantations, consistent with shading and buffering effects of plantations on edge microclimate. Plantation edge effects were less pronounced in summer, although higher water use efficiency of edge than interior woodland trees indicated possible competition for water between plantation trees and woodland edge trees in the drier months (an effect that might have been more pronounced were there no firebreak between the two land uses). Scaling up of leaf-level water relations to stand transpiration using a Jarvis-type phenomenological model indicated similar differences between edge types. That is, transpiration was greater at pasture than plantation edges in summer months (most likely due to greater water availability at pasture edges), resulting in significantly greater estimates of annual transpiration at pasture than plantation edges (430 vs. 343lm−2year−1, respectively). Our study highlights the need for landscape-level water flux models to account for edge effects on stand transpiration, particularly in highly fragmented landscapes.

Keywords: forest ecophysiology; stomatal regulation; transpiration; water relations

Journal Article.  8686 words.  Illustrated.

Subjects: Plant Sciences and Forestry

Full text: subscription required

How to subscribe Recommend to my Librarian

Users without a subscription are not able to see the full content. Please, subscribe or login to access all content.