The Tasmanian Endemic Shrub Acacia axillaris: Conservation Ecology Applied to the Question of Rarity or Vulnerability

1999 ◽  
Vol 47 (1) ◽  
pp. 97 ◽  
Author(s):  
J. B. Kirkpatrick ◽  
A. J. J. Lynch ◽  
L. Gilfedder

Acacia axillaris Benth. had been recommended for downgrading from a conservation status of vulnerable to one of rare in response to changed knowledge of its distribution. Ecological investigations of its phytosociology, stand structure, germination requirements, soil seed store and response to fire and disturbance indicate, however, that it is susceptible to elimination by fire regimes that allow the survival of most of its co-occurring species and most other Australian species of Acacia. The species is also vulnerable to land clearance and weed competition in the lowland part of its range, which is largely on private land.A. axillaris may be a refugial species, better suited to glacial Tasmania than to interglacial Tasmania. On ecological evidence, the species should retain its conservation status of vulnerable to extinction.

2021 ◽  
Vol 53 (1) ◽  
pp. 95-101
Author(s):  
Gintaras Kantvilas

AbstractThe lichen genus Lecanactis Körb. in Tasmania comprises six species: L. abietina (Ach.) Körb., which is widespread and pan-temperate; L. latispora Egea & Torrente and L. neozelandica Egea & Torrente, both shared with New Zealand and with the former recorded here from the Auckland Islands for the first time; L. mollis (Stirt.) Frisch & Ertz, shared with Victoria and New Zealand; L. aff. dilleniana (Ach.) Körb., a European species recorded provisionally for Tasmania on the basis of several sterile collections; L. scopulicola Kantvilas, which is described here as new to science and apparently a Tasmanian endemic. This new taxon occurs in rocky underhangs and is characterized by a thick, leprose thallus containing schizopeltic acid, and 3-septate ascospores, 19–30 × 4.5–6 μm. Short descriptions and a discussion of distribution and ecology are given for all species. A key for all 11 Australian species of the genus is provided, including L. subfarinosa (C. Knight) Hellb. and L. tibelliana Egea & Torrente, which are recorded for Australia for the first time, and L. platygraphoides (Müll.Arg.) Zahlbr., a first record for New South Wales. Lecanactis spermatospora Egea & Torrente and L. sulphurea Egea & Torrente are also included.


1998 ◽  
Vol 4 (4) ◽  
pp. 296 ◽  
Author(s):  
M. C. Calver ◽  
J. Dell

Sixteen mammal species and 22 bird species whose distributions extended into southwestern Australian forests before European settlement have been listed as threatened at some time in Commonwealth legislation, State legislation, or action plans of Environment Australia or its predecessors. Confident assessment of the causes of conservation status is hampered by poor base-line data, few studies of putative impacts and a preponderance of circumstantial or anecdotal rather than experimental evidence. However, introduced foxes were Implicated In the current conservation status of 62% of the mammal species recognized, while 44% of them were negatively impacted by feral cats, 44% by agricultural clearing and 44% by changed fire regimes. Forestry practices were impllcated in the conservation status of only one mammal species. For the bird species recognized, changed fire regimes had the greatest negative impact (45% affected), agricultural clearing affected 41%, draining of wetlands affected 32% and grazing by livestock affected 22%. Forestry practices were not directly implicated in the conservation status of any bird species. While these results suggest that forestry has had minimal direct impact on the mammals and birds of the forests, the conclusion should be treated cautiously because of the poor data. While awaiting a rigorous evaluation, we argue for a strong precautionary approach to forestry in the region. With proper forest management and sound sylvicultural [sic] treatment there is no reason why there should not be built up on the wreckage of the once splendid forests of Western Australia tended forests which will yield for all time 100 cubic feet of timber per acre per year. Lane-Poole (1920). There are many reasons why Australian environmentalists would like to end logging in native forests. The preservation of wilderness, aesthetics, an almost religious identification with old growth forests and the conservation of forest wildlife figure importantly in environmental efforts to restrict logging. Wilderness and a personal identification with trees and undisturbed forests are fundamentally incompatible with logging. Recher (1996).


2015 ◽  
Vol 24 (1) ◽  
pp. 59 ◽  
Author(s):  
Emma E. Burgess ◽  
Patrick Moss ◽  
Murray Haseler ◽  
Martine Maron

The post-fire response of vegetation reflects not only a single fire event but is the result of cumulative effects of previous fires in the landscape. For effective ecological fire management there is a need to better understand the relationship between different fire regimes and vegetation structure. The study investigated how different fire regimes affect stand structure and composition in subtropical eucalypt woodlands of central Queensland. We found that fire history category (i.e. specific combinations of time since fire, fire frequency and season of last burn) strongly influenced richness and abundance of species categorised as mid-storey trees and those individuals currently in the mid-level strata. Time since fire and fire frequency appeared to have the strongest influence. A longer time since fire (>4 years since last burn), combined with infrequent fires (<2 fires in 12 year period) appeared to promote a dense mid-storey with the opposite conditions (<4 years since last burn; >2 fires in 12 year period) promoting more-open woodlands. Consideration of these combined fire regime attributes will allow fire managers to plan for a particular range of fire-mediated patches to maintain the desired diversity of vegetation structures.


2013 ◽  
Vol 22 (3) ◽  
pp. 394 ◽  
Author(s):  
Grant L. Harley ◽  
Henri D. Grissino-Mayer ◽  
Sally P. Horn

We focussed on the influence of historical fire and varied fire management practices on the structure of globally endangered pine rockland ecosystems on two adjacent islands in the Florida Keys: Big Pine Key and No Name Key. We reconstructed fire history in two stands from fire scars on South Florida slash pines (Pinus elliottii Engelm. var. densa Little & Dor.) that were accurately dated using dendrochronology, and quantified stand structure to infer successional trajectories. Fire regimes on Big Pine Key and No Name Key over the past 150 years differed in fire return interval and spatial extent. Fire scar analysis indicated that fires burnt at intervals of 6 and 9 years (Weibull median probability interval) on Big Pine Key and No Name Key with the majority of fires occurring late in the growing season. On Big Pine Key, pine recruitment was widespread, likely due to multiple, widespread prescribed burns conducted since 2000. No Name Key experienced fewer fires than Big Pine Key, but pines recruited at the site from at least the 1890s through the 1970s. Today, pine recruitment is nearly absent on No Name Key, where fire management practices since 1957 could result in loss of pine rockland habitat.


2021 ◽  
Author(s):  
Fátima Arrogante-Funes ◽  
Inmaculada Aguado ◽  
Emilio Chuvieco

Abstract. Fire is a natural phenomenon that has played a critical role in transforming the environment and maintaining biodiversity at a global scale. However, the plants in some habitats have not developed strategies for recovery from fire or have not adapted to the changes taking place in their fire regimes. Maps showing ecological vulnerability to fires could contribute to environmental management policies in the face of global change scenarios. The main objective of this study is to assess and map ecological vulnerability to fires on a global scale. To this end, we created ecological value and post-fire regeneration delay indices on the basis of existing global databases. Two ecological value indices were identified: biological distinction and conservation status. For the post-fire regeneration delay index, various factors were taken into account, including the type of fire regime, the increase in the frequency and intensity of forest fires and the potential soil erosion they can cause. These indices were combined by means of a qualitative cross-tabulation to create a new index evaluating ecological vulnerability to fire. The results showed that global ecological value could be reduced by as much as 50 %, due to fire perturbation of ecosystems that are poorly adapted to it. The terrestrial biomes most affected are the tropical and subtropical moist broadleaf forest; tundra; mangroves; tropical and subtropical coniferous forests; and tropical and subtropical dry broadleaf forests.


2020 ◽  
Vol 68 (2) ◽  
pp. 119
Author(s):  
R. J. Fensham ◽  
B. Laffineur ◽  
M. McVeigh

Eucalyptus argophloia is a species with a small geographic range occurring in a productive landscape with a subhumid climate. The past distribution of the species was assessed from remnant vegetation and standing paddock trees. The species grows in three specific vegetation types within its geographic range, and based on densities in remnant vegetation and reduction of habitat, it is estimated that the population has been reduced by 94.2%. There is very little regeneration of the species including on ungrazed roadsides, and further decline of the species is expected. The species can be categorised under IUCN Red Listing criteria as Critically Endangered. The present study provides a method for using habitat association, population decline and stand structure for conservation assessment of threatened tree species in productive landscapes.


2001 ◽  
Vol 23 (2) ◽  
pp. 185 ◽  
Author(s):  
S Murphy

THE bare-rumped sheathtailed bat Saccolaimus saccolaimus is a poorly understood species that has a wide distribution covering parts of India, Sri Lanka, Thailand, Myanmar, Malaya, Indonesia, New Guinea, the Solomon Islands and Northern Australia (Bonaccorso 1998). First collected in Australia by De Vis near Cardwell, the current known distribution in Queensland (Qld) extends from Bowen to Cooktown with one isolated specimen collected near Coen on Cape York Peninsula (Hall 1995; Duncan et al. 1999). It has also been recorded in the Alligator River area in the Northern Territory (McKean et al. 1981). The conservation status of S. saccolaimus in Qld has recently been defined as ?Critically Endangered?, and the species has not been recorded anywhere in Australia for at least 18 years (Duncan et al. 1999; Menkhorst and Knight 2001). The likely reasons for the apparent decline are unclear, but may involve land-clearing and changed fire regimes in the coastal zone where it is thought to occur (Duncan et al. 1999). In contrast, Bonaccorso (1998) considers S. saccolaimus to be secure, albeit also poorly known in Papua New Guinea.


2015 ◽  
Author(s):  
Mike Feduck ◽  
Philippe Henry ◽  
Richard Winder ◽  
David Dunn ◽  
René I Alfaro ◽  
...  

Wildfires and mountain pine beetle (MPB) attacks are important contributors to the development of stand structure in lodgepole pine, and major drivers of its evolution. The historical pattern of these events have been correlated with variation in cone serotiny (possessing cones that remain closed and retain seeds until opened by fire) across the Rocky Mountain region of Western North America. As climate change brings about a marked increase in the size, intensity, and severity of our wildfires, it is becoming increasingly important to study the genetic basis of serotiny as an adaptation to wildfire. Knowledge gleaned from these studies would have direct implications for forest management in the future, and for the future. In this study, we collected physical data and DNA samples from 122 trees of two different areas in the IDF-dk of British Columbia; multi-cohort stands (Cariboo-Chilcotin) with a history of mixed-severity fire and frequent MPB disturbances, and single-cohort stands (Logan Lake) with a history of stand replacing (crown) fire and infrequent MPB disturbances. We used QuantiNemo to construct simulated populations of lodgepole pine at five different growth rates, and compared the statistical outputs to physical data, then ran a random forest analysis to shed light on sources of variation in serotiny. We also sequenced 39 SNPs, of which 23 failed or were monomorphic. The 16 informative SNPs were used to calculate HO and HE, which were included alongside genotypes for a second random forest analysis. Our best random forest model explained 33% of variation in serotiny, using simulation and physical variables. Our results highlight the need for more investigation into this matter, using more extensive approaches, and also consideration of alternative methods of heredity such as epigenetics.


2019 ◽  
Vol 65 (No. 7) ◽  
pp. 272-282 ◽  
Author(s):  
Sajad Ghanbari ◽  
Kiomars Sefidi ◽  
Matthew Aghai

Yew (Taxus baccata L.) is one of the most important and threatened tree species in the Arasbaran region of northwestern Iran. To understand the natural stand structure of yew forests to inform forest management, we assessed the structural characteristics and composition of yew communities using the nearest neighbour and full callipering method at three sites with different conservation histories. Within a one-hectare sampling area, tree species identity, diameter, height, and crown diameter were measured. In each of these sampling areas, 56 sample points were surveyed in a 25 m × 25 m grid for tree species identity, diameter, height, and distance from reference to neighbour trees. To quantify the structural characteristics in areas of different conservation status, some indices were calculated including mingling, distance between reference tree and its nearest neighbouring trees, diameter and height differentiation, uniform angle, and Clark-Evans index. Results revealed that four species – hornbeam (68%), maple (8%), yew (7%), and oak (5.2%) – composed 88% of the tree species. The majority of trees had a short distance (2–3 m) between neighbours. The mean diameter differentiation index for long-term and short-term conservation areas was 0.59 and 0.06, respectively. The uniform angle index showed that there was no class value = “1” at all three sites. In the long-term enclosed area, Clark-Evans index was 1.18. In short-term enclosed areas, it was less than 1 (0.82). At all sites, yew trees were in the least vital class. We conclude that enclosing affects the yew stand structure, specifically in long-term periods of enclosure.


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