Demographic Effects of Severe Fire in Montane Shrubland on Tasmania’s Central Plateau

Judy A Foulkes,Lynda D Prior,Steven W J Leonard,David M J S Bowman

doi:10.3390/fire4030032

Judy A Foulkes, Lynda D Prior + Show 2 more

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https://doi.org/10.3390/fire4030032

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Abstract

Australian montane sclerophyll shrubland vegetation is widely considered to be resilient to infrequent severe fire, but this may not be the case in Tasmania. Here, we report on the vegetative and seedling regeneration response of a Tasmanian non-coniferous woody montane shrubland following a severe fire, which burned much of the Great Pine Tier in the Central Plateau Conservation Area during the 2018–2019 fire season when a historically anomalously large area was burned in central Tasmania. Our field survey of a representative area burned by severe crown fire revealed that more than 99% of the shrubland plants were top-killed, with only 5% of the burnt plants resprouting one year following the fire. Such a low resprouting rate means the resilience of the shrubland depends on seedling regeneration from aerial and soil seedbanks or colonization from plants outside the burned area. Woody species’ seedling densities were variable but generally low (25 m−2). The low number of resprouters, and reliance on seedlings for recovery, suggest the shrubland may not be as resilient to fire as mainland Australian montane shrubland, particularly given a warming climate and likely increase in fire frequency.

Highlights

Introduction and Chad MHoffmanShrubs, defined here as woody plants less than 3 m high, have often been considered as grassland and woodland invaders, contributing to woody thickening
Our study area was the montane shrublands within the Central Plateau Conservation Area (CPCA), near Lake Augusta, to the west of yingina/Great Lake, on Tasmania’s Central Plateau at an elevation of approximately 1100 m (Figures 1 and 2)
Our study contributes to understanding the fire ecology of Tasmanian montane shrublands which are rarely burned, and provides a record of some of the impacts of the anomalous 2018–2019 fire season that impacted several regions within the Tasmanian

Summary

Introduction

Introduction and Chad MHoffmanShrubs, defined here as woody plants less than 3 m high, have often been considered as grassland and woodland invaders, contributing to woody thickening. Shrublands provide important ecosystem functions and services, such as wildlife habitat and food resource, sizeable carbon sinks, prevention of soil erosion, and hydrological regulation [2,4,5,6]. These two opposing points of view of shrublands affect how natural and anthropogenic wildfires are viewed. If shrublands are an important component of the landscape fire management is critical. Shrubs can be one of the most flammable components within a montane landscape, and under a warming climate shrub encroachment into grasslands may increase [12,13]. Severe wildfires are expected to become more frequent with a rapidly warming climate [14,15,16]

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