Abstract
Aims: Informed management of savanna systems depends on understanding determinates of composition, structure and function, particularly in relation to woody-plant components. This understanding needs to be regionally based, both past and present. In this study, Holocene plant patterns are explored at a site within the eucalypt savannas of northern Australia. Australian savannas are the least developed globally and uniquely placed to track ecological change. Location: Northern Territory, Australia.
Methods: Palynological analyses were undertaken on a 5-m sediment core, spanning the last 10,700 calendar years. Pollen was categorised to capture vegetation type, classified further according to plant function and/or environmental response. Detrended Correspondence Analysis was used to quantify ecological dissimilarities through time.
Results: At the Pleistocene transition, grasses were abundant then declined and remained low relative to increased woody cover from the mid-late Holocene. Savanna composition gradually transitioned from Corymbia to Eucalyptus dominance until significantly disturbed by a phase of repeated, extreme climate events. Highest non-savanna variability in terrestrial and wetland plant types formed mixed vegetation communities through the mid-Holocene.
Conclusions: Savannas are not homogeneous but the product of plant changes in multiple dimensions. In the Northern Territory, dynamic though restricted non-eucalypt shifts are embedded within larger, slower eucalypt change processes. Primary climate–vegetation relationships determine the long-term fire regime. The role of large but infrequent disturbance events in maintaining savanna diversity are significant, in degrees of impact on tree–grass turnover, its form and the extent of vegetation recovery. People's landscape interactions were found to be interwoven within this feedback hierarchy.
| Original language | English |
|---|---|
| Article number | e13158 |
| Number of pages | 16 |
| Journal | Journal of Vegetation Science |
| Volume | 33 |
| Issue number | 6 |
| DOIs | |
| Publication status | Published - 1 Nov 2022 |
Bibliographical note
Funding Information:This research was funded by the Australian Research Council (ARC) Laureate FL140100044 and Centre of Excellence awards (CE170100015), both allocated to Michael I. Bird. An Australian Institute of Nuclear Science and Engineering Postgraduate Research Award (12143, to Emma Rehn) assisted the in funding of dating samples. Lindsay B. Hutley is recipient of an ARC Discovery Project DP130100334.
Funding Information:
This research was conducted under an Australian Research Council (ARC) Laureate Fellowship (FL140100044) and Australian Research Council Centre of Excellence award (CE170100015) to Michael I. Bird. An AINSE PGRA (Postgraduate Research Award 12143) assisted in the funding of dating samples. Lindsay B. Hutley is recipient of Discovery Project DP130100334. Vladimir Levchenko acknowledges the financial support from the Australian Government for the Centre for Accelerator Science at the Australian Nuclear Science-Technology Organisation (ANSTO), where the measurements were done, through the National Collaborative Research Infrastructure Strategy (NCassandra RoweIS), and expresses gratitude to the staff of the radiocarbon laboratory who processed our samples. We thank the Northern Land Council for permission to undertake the research described in this study. James Cook University and Charles Darwin AUTHOR: CD has long been dead; please rephraseprovided institutional support throughout this research. We thank both reviewers and the journal editorial staff for their time spent reading this submission and resulting constructive feedback. Open access publishing facilitated by James Cook University, as part of the Wiley - James Cook University agreement via the Council of Australian University Librarians. Open access publishing facilitated by James Cook University, as part of the Wiley - James Cook University agreement via the Council of Australian University Librarians.
Funding Information:
This research was conducted under an Australian Research Council (ARC) Laureate Fellowship (FL140100044) and Australian Research Council Centre of Excellence award (CE170100015) to Michael I. Bird. An AINSE PGRA (Postgraduate Research Award 12143) assisted in the funding of dating samples. Lindsay B. Hutley is recipient of Discovery Project DP130100334. Vladimir Levchenko acknowledges the financial support from the Australian Government for the Centre for Accelerator Science at the Australian Nuclear Science‐Technology Organisation (ANSTO), where the measurements were done, through the National Collaborative Research Infrastructure Strategy (NCassandra RoweIS), and expresses gratitude to the staff of the radiocarbon laboratory who processed our samples. We thank the Northern Land Council for permission to undertake the research described in this study. James Cook University and Charles Darwin AUTHOR: CD has long been dead; please rephraseprovided institutional support throughout this research. We thank both reviewers and the journal editorial staff for their time spent reading this submission and resulting constructive feedback. Open access publishing facilitated by James Cook University, as part of the Wiley ‐ James Cook University agreement via the Council of Australian University Librarians. Open access publishing facilitated by James Cook University, as part of the Wiley ‐ James Cook University agreement via the Council of Australian University Librarians.
Publisher Copyright:
© 2022 The Authors. Journal of Vegetation Science published by John Wiley & Sons Ltd on behalf of International Association for Vegetation Science.
