Phytophthora cinnamomi in native vegetation communities of southern Victoria—morphological variation and paragyny among isolates

2003 ◽  
Vol 32 (3) ◽  
pp. 403 ◽  
Author(s):  
Rosalie Daniel ◽  
Barbara A. Wilson ◽  
David M. Cahill
Keyword(s):  
Morphological Variation ◽  
Phytophthora Cinnamomi ◽  
Native Vegetation ◽  
Vegetation Communities

scholarly journals The plant pathogen Phytophthora cinnamomi influences habitat use by the obligate nectarivore honey possum (Tarsipes rostratus)

2016 ◽  
Vol 64 (2) ◽  
pp. 122 ◽  
Author(s):  
Shannon J. Dundas ◽  
Giles E. St J. Hardy ◽  
Patricia A. Fleming
Keyword(s):  
Habitat Use ◽  
Plant Species ◽  
Plant Pathogens ◽  
Phytophthora Cinnamomi ◽  
Habitat Preferences ◽  
Flowering Plant ◽  
Food Sources ◽  
Vegetation Communities ◽  
Vegetation Surveys ◽  
Honey Possum

Introduced plant pathogens can devastate susceptible plant communities, and consequently impact on animal communities reliant on plants for food and habitat. Specifically, plant pathogens change the floristic diversity of vegetation communities, thereby reducing availability of food sources for fauna (e.g. pollen and nectar) and result in major changes to habitat structure when canopy and understorey plant species succumb to disease. Phytophthora cinnamomi poses a threat to flowering plant species (e.g. Banksia species) which are important food sources for nectarivorous fauna. The honey possum (Tarsipes rostratus) is the only obligate nectarivorous non-flying mammal living on a restrictive diet of nectar and pollen; consequently, these tiny mammals are likely to be particularly vulnerable to the landscape-wide devastation caused by P. cinnamomi. We investigated habitat selection by honey possums in a vegetation community infested with P. cinnamomi to determine how these mammals respond to habitat affected by this pathogen. Over four seasons, 18 honey possums were fitted with radio-transmitters and tracked to identify habitat preferences. Vegetation surveys were compared for locations selected by honey possums (as determined from tracking) and randomly selected sites. Radio-tracking revealed that sites selected by honey possums were significantly taller, denser, and more floristically diverse than their paired random locations. The presence of P. cinnamomi influences habitat use by honey possums, but animals show resilience in terms of using the best of what is available in both P. cinnamomi–affected and unaffected locations. Habitat patches comprising less susceptible species, or plants that have yet to succumb to infection, provide refuge and food resources for honey possums. Management to reduce the spread of existing P. cinnamomi infestations and prevent contamination of new locations will benefit vegetation communities and associated faunal communities, while identifying honey possum food plant species that are resilient to the pathogen may support revegetation attempts.

scholarly journals Evaluating the Impact of Grazing Cessation and Reintroduction in Mixed Prairie Using Raster Time Series Analysis of Landsat Data

2021 ◽  
Vol 13 (17) ◽  
pp. 3397
Author(s):  
Dandan Xu ◽  
Jeff K. Harder ◽  
Weixin Xu ◽  
Xulin Guo
Keyword(s):  
Time Series ◽  
Native Vegetation ◽  
Vegetation Communities ◽  
Fresh Biomass ◽  
Effective Time ◽  
Green Cover ◽  
Time Periods ◽  
Biophysical Indicators ◽  
The Impact ◽  
Upland Grassland

Great efforts have been made to manage and restore native prairies to protect native species, enrich biodiversity, protect ecological resilience, and maintain ecosystem services. Much of this has been focused on preventing degradation from overgrazing and crop conversion. Understanding the consequences of management polices is important to identify best practices. Previous research has compared restoration outcomes from variable intensity grazing, prescribed fire, and grazing removal. However, few studies have explored the optimal durations of management practices and variation in restoration outcomes among vegetation communities. This study evaluates whether the impact of grazing cessation and reintroduction varies among native vegetation communities and measures the effective time periods of grazing cessation and reintroduction. Restoration outcomes were evaluated using four biophysical indicators (fresh biomass, soil organic matter, green cover, and litter cover) and two vegetation indices (normalized difference vegetation index (NDVI) and normalized difference water index (NDWI)) measured from Landsat images using seasonal Kalman filter and raster time series analysis. The results show that: (i) Grazing cessation increased soil organic matter and green cover while decreasing fresh biomass compared to moderate grazing management, while grazing reintroduction influences those indicators in an opposite direction; (ii) The effective time period for prairie conservation is about 11–14 years and varies among vegetation communities and biophysical indicators; (iii) The effective intensity of grazing cessation is highest in valley grassland, moderate in upland grassland, and mildest in sloped grassland; (iv) Grazing reintroduction returned the three native vegetation communities to the initial condition (i.e., the stage in 1985 before large grazers were removed), with less time than the time consumed for grazing cessation to restore the prairie ecosystem to the maximum changes; (v) Grazing reintroduction effectively influences upland and valley grasslands for 7 to 9 years, varying from different indicators, while it continuously affected sloped grassland with no clear time lag; (vi) The intensity of grazing reintroduction was strongest in sloped grassland, moderate in upland grassland, and mildest in valley grassland. The results of this study suggest expected time periods for prairie management methods to achieve results.

scholarly journals Galápagos Rail Laterallus spilonotus population change associated with habitat invasion by the Red-barked Quinine Tree Cinchona pubescens

2010 ◽  
Vol 21 (2) ◽  
pp. 221-227 ◽  
Author(s):  
W. GREGORY SHRIVER ◽  
JAMES P. GIBBS ◽  
HARA W. WOLTZ ◽  
NICOLE P. SCHWARZ ◽  
MARGARET A. PEPPER
Keyword(s):  
Population Change ◽  
Oceanic Islands ◽  
Native Vegetation ◽  
Santa Cruz Island ◽  
Santa Cruz ◽  
Vegetation Communities ◽  
Galapagos Archipelago ◽  
Management Actions ◽  
Cinchona Pubescens ◽  
Habitat Invasion

SummarySpecies on oceanic islands are more likely to be endemic as well as more extinction-prone than those on continents. The Galápagos Rail Laterallus spilonotus, endemic to the Galápagos Archipelago, is presently known to occur on just four of its seven previously occupied islands and is facing multiple threats to its persistence. In this study, we compared the rail’s occurrence and abundance at 193 survey points between 2000 and 2007 on Santa Cruz Island and examined the influence of an invasion of the habitat of the species by the exotic Red-barked Quinine Tree Cinchona pubescens. We detected a 13% reduction in rail occurrence and a 31% reduction in abundance between 2000 and 2007. Rail abundance declined more in low elevation areas (< 719 m) and outside of Cinchona pubescens removal areas but not in areas where Cinchona pubescens was removed. Insofar as Galápagos Rails responded positively to management actions that promote and maintain native vegetation, we conclude that restoration projects that restore native vegetation communities benefit this apparently declining endemic bird for which more focused conservation attention is warranted.

scholarly journals Distribution and diversity of Phytophthora across Australia

2017 ◽  
Vol 23 (2) ◽  
pp. 150 ◽  
Author(s):  
Treena I. Burgess ◽  
Diane White ◽  
Keith M. McDougall ◽  
Jeff Garnas ◽  
William A. Dunstan ◽  
...  
Keyword(s):  
High Throughput Sequencing ◽  
Conservation Management ◽  
Phytophthora Cinnamomi ◽  
Environmental Dna ◽  
Phytophthora Species ◽  
Native Vegetation ◽  
New Techniques ◽  
Future Studies ◽  
Isolation Methods ◽  
Potential Impact

The introduction and subsequent impact of Phytophthora cinnamomi within native vegetation is one of the major conservation issues for biodiversity in Australia. Recently, many new Phytophthora species have been described from Australia’s native ecosystems; however, their distribution, origin, and potential impact remain unknown. Historical bias in Phytophthora detection has been towards sites showing symptoms of disease, and traditional isolation methods show variable effectiveness of detecting different Phytophthora species. However, we now have at our disposal new techniques based on the sampling of environmental DNA and metabarcoding through the use of high-throughput sequencing. Here, we report on the diversity and distribution of Phytophthora in Australia using metabarcoding of 640 soil samples and we compare the diversity detected using this technique with that available in curated databases. Phytophthora was detected in 65% of sites, and phylogenetic analysis revealed 68 distinct Phytophthora phylotypes. Of these, 21 were identified as potentially unique taxa and 25 were new detections in natural areas and/or new introductions to Australia. There are 66 Phytophthora taxa listed in Australian databases, 43 of which were also detected in this metabarcoding study. This study revealed high Phytophthora richness within native vegetation and the additional records provide a valuable baseline resource for future studies. Many of the Phytophthora species now uncovered in Australia’s native ecosystems are newly described and until more is known we need to be cautious with regard to the spread and conservation management of these new species in Australia’s unique ecosystems.

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