Resilience of trees and the vulnerability of grasslands to climate change in temperate Australian wetlands

Neil Saintilan, Sharon Bowen, Owen Maguire, Sara S. Karimi, Li Wen, Megan Powell, Matthew J. Colloff, S. Sandi, P. Saco, J. Rodriguez

Research output: Contribution to journalArticleResearchpeer-review

Abstract

Objectives: Observations from wetlands across the globe suggest a consistent pattern of woody encroachment into wetland grasslands, altering habitat structure and ecological function. The extent to which hydrological changes have contributed to woody invasion of wetland grasslands is unclear. Our objective was to compare rates of woody encroachment in Australian floodplain wetlands between wet and dry hydrological phases. We test the hypothesis that contraction of non-woody wetland vegetation (grasses and rushes) would be concentrated in dry phases, co-incident with recruitment of the River Red Gum Eucalyptuscamaldulensis lower in the floodplain. Methods: We conduct the first detailed mapping of habitat change in two of the largest forested wetlands in inland Australia, comparing wet and dry hydrological phases. Detailed photogrammetry, supported by extensive ground survey, allowed the interpretation of high resolution aerial photography to vegetation community level. Results: We found a consistent pattern of decline in non-woody vegetation, particularly amongst grasses utilising the C4 photosynthetic pathway. The C4 grasses Pseudoraphisspinescens and Paspalumdistichum showed steep declines in the Barmah Millewa and Macquarie Marshes respectively, being replaced by River Red Gum E. camaldulensis. C3 sedges proved more resilient in both systems. Conclusions: Our results suggest that a pattern of tree expansion into non-woody wetland vegetation, characteristic of wetlands across the globe, is a major habitat structural change in the Australian floodplain wetlands studied. Projected hydrological impacts of climate change are likely to further restrict wetland grass foraging habitat in these semi-arid floodplain wetlands.

Original languageEnglish
JournalLandscape Ecology
Early online date12 Jan 2021
DOIs
Publication statusE-pub ahead of print - 12 Jan 2021

Keywords

  • Canopy condition
  • Climate change
  • Drought
  • Wetland
  • Woody encroachment

Fingerprint Dive into the research topics of 'Resilience of trees and the vulnerability of grasslands to climate change in temperate Australian wetlands'. Together they form a unique fingerprint.

Cite this