scholarly journals Evidence for convergent evolution among phylogenetically distant rare species of Tetratheca (Elaeocarpaceae, formerly Tremandraceae) from Western Australia

2007 ◽  
Vol 20 (2) ◽  
pp. 126 ◽  
Author(s):  
Ryonen Butcher ◽  
Margaret Byrne ◽  
Darren M. Crayn
Keyword(s):  
Western Australia ◽  
Rare Species ◽  
Cladistic Analysis ◽  
Geographic Area ◽  
Arid Environments ◽  
High Conservation ◽  
Superficial Similarity ◽  
Evolutionary Lineages ◽  
Semi Arid

Morphological and molecular investigations of taxon relationships among rare species of Tetratheca Sm. occurring near Koolyanobbing, Western Australia, have confirmed the distinctness of T. aphylla F.Muell., T. harperi F.Muell. and T. paynterae Alford and identified three new rare taxa from collections affiliated with T. aphylla and T. paynterae. The recognition of these taxa at specific and sub-specific ranks is based on their different degrees of morphological and molecular divergence, combined with geographic disjunction. Cladistic analysis of nrDNA internal transcribed spacer and cpDNA trnL-trnF sequences from a range of Tetratheca species from Western Australia and the eastern states indicates that T. aphylla, T. harperi and T. paynterae belong to three separate evolutionary lineages and that the endemism displayed among these taxa to small, disjunct ranges within the same geographic area, is a result of in situ speciation due to historical fragmentation. These results exemplify the extremely high conservation value of the Yilgarn banded ironstone ranges. The superficial similarity among the study taxa in having a ‘leafless’ habit can be seen to be adaptive convergence in response to the marginal and semi-arid environments in which they occur, and this character is highly homoplastic within the genus.

scholarly journals A hydrological framework for persistent river pools in semi-arid environments

2020 ◽  
Author(s):  
Sarah A. Bourke ◽  
Margaret Shanafield ◽  
Paul Hedley ◽  
Shawan Dogramaci
Keyword(s):  
Western Australia ◽  
Groundwater Discharge ◽  
Geological Mapping ◽  
Diagnostic Tools ◽  
Arid Environments ◽  
Hydrogeological Characteristics ◽  
Through Flow ◽  
Bedrock Aquifers ◽  
North Western ◽  
Semi Arid

Abstract. Persistent surface water pools along non-perennial rivers represent an important water resource for the plants, animals, and humans that inhabit semi-arid regions. While ecological studies of these features are not uncommon, these are rarely accompanied by a rigorous examination of the hydrological and hydrogeological characteristics that create or support the pools. Here we present an overarching framework for understanding the hydrology of persistent pools based on data from 22 pools in the Hamersley Basin in Western Australia. Three dominant mechanisms that control the occurrence of persistent pools have been identified; perched pools, through flow pools and groundwater discharge pools. Groundwater discharge pools are further categorized into those that are present because of a geological contact or barrier, and those that are controlled by topography. A suite of diagnostic tools (including geological mapping, hydraulic data and hydrochemical surveys) is generally required to identify the mechanism supporting persistent pools. Perched pools are sensitive to climate variability but their persistence is largely independent of groundwater withdrawals. Water fluxes to pools from alluvial and bedrock aquifers can vary seasonally and resolving these inputs is generally non-trivial. The susceptibility of through-flow and groundwater discharge pools to climate variations and groundwater withdrawals depends on the mechanism of pool persistence and the spatial distribution of stressors relative to the pool. Although this framework was developed in the context of north-western Australia, this framework can also be applied to pools and springs found along non-perennial rivers around the world.

Prolonged isolation and persistence of a common endemic on granite outcrops in both mesic and semi-arid environments in south-western Australia

2014 ◽  
Vol 41 (11) ◽  
pp. 2032-2044 ◽  
Author(s):  
Sarah-Louise Tapper ◽  
Margaret Byrne ◽  
Colin J. Yates ◽  
Gunnar Keppel ◽  
Stephen D. Hopper ◽  
...  
Keyword(s):  
Western Australia ◽  
Arid Environments ◽  
Granite Outcrops ◽  
Semi Arid

scholarly journals In-situ unsaturated zone stable water isotope (<sup>2</sup>H and <sup>18</sup>O) measurements in semi-arid environments using tunable off-axis integrated cavity output spectroscopy

2015 ◽  
Vol 12 (6) ◽  
pp. 6115-6149 ◽  
Author(s):  
M. Gaj ◽  
M. Beyer ◽  
P. Koeniger ◽  
H. Wanke ◽  
J. Hamutoko ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Pore Water ◽  
Isotope Analysis ◽  
Vacuum Extraction ◽  
Arid Environments ◽  
Soil Pore Water ◽  
Cavity Output ◽  
Spatio Temporal ◽  
Semi Arid

Abstract. Stable isotopes (deuterium, 2H, and oxygen-18, 18O) of soil pore water were measured directly in the field using tunable off-axis integrated cavity output spectroscopy (OA-ICOS) and commercially available soil gas probes in a semi-arid region of the Cuvelai-Etosha-Basin, Namibia. High spatial and temporal resolution was achieved in the study area with reasonable accuracy and measurements were in agreement with laboratory-based cryogenic vacuum extraction and subsequent cavity ring down laser spectroscopic isotope analysis (CRDS). After drift correction of the isotope data, mean precision for over 140 measurements of two consecutive field campaigns in June and November 2014 were 1.8 and 0.46 ‰ for δ2H and 18O, respectively. Mean Accuracy using quality check standards was 5 and 0.3 ‰ for δ2H and δ18O, respectively. Results support the applicability of an in-situ measurement system for the determination of stable isotopes in soil pore water. Spatio-temporal variability could be deduced with the observed data in an extremely dry evaporation dominated environment which was sporadically affected by intermittent rainfall.

Ecotypic variation between and within two populations of Trifolium tomentosum (woolly clover) from Syria and Western Australia: its success as a colonising species

1999 ◽  
Vol 50 (8) ◽  
pp. 1443 ◽  
Author(s):  
Sarita Jane Bennett
Keyword(s):  
Western Australia ◽  
Function Analysis ◽  
Acid Soils ◽  
Arid Environment ◽  
Arid Environments ◽  
Alkaline Soils ◽  
Field Station ◽  
Ecotypic Variation ◽  
Site Variation ◽  
Semi Arid

Ecotypic variation was studied between and within populations of Trifolium tomentosum (woolly clover) using seed that was collected from 2 semi-arid environments: Tel Hadya, Syria, and Pingrup, Western Australia. The seed was collected from 64 subplots within a 40-m2 grid at each site and the material was grown at the University of Western Australia Field Station at Shenton Park, Perth. Fifteen morphological characters were scored and were analysed using analysis of variance, principal components analysis, and discriminant function analysis. Material from the 2 sites was separated using multivariate analysis, with the seed from Tel Hadya containing more within-site variation. It is suggested that the lack of within-site variation observed at Pingrup is the result of a number of factors: a limited amount of genetic diversity being present in the original introduced material, a preference of T. tomentosum for alkaline soils rather than the acid soils predominantly occurring in Western Australia, the harsh selection pressures present in a semi-arid environment, and a limited time for genotypes to adapt to specific micro-niches within each environment. The results are used to contribute to our understanding of the success of colonising species in semi-arid environments.

scholarly journals In situ unsaturated zone water stable isotope (<sup>2</sup>H and <sup>18</sup>O) measurements in semi-arid environments: a soil water balance

2016 ◽  
Vol 20 (2) ◽  
pp. 715-731 ◽  
Author(s):  
Marcel Gaj ◽  
Matthias Beyer ◽  
Paul Koeniger ◽  
Heike Wanke ◽  
Josefina Hamutoko ◽  
...  
Keyword(s):  
Stable Isotopes ◽  
Water Balance ◽  
Soil Water ◽  
Root Zone ◽  
Soil Water Balance ◽  
Vacuum Extraction ◽  
Rain Event ◽  
Arid Environments ◽  
Semi Arid

Abstract. Stable isotopes (deuterium, 2H, and oxygen-18, 18O) of soil water were measured in the field using a liquid water isotope analyzer (tunable off-axis integrated cavity output spectroscope, OA-ICOS, LGR) and commercially available soil gas probes (BGL-30, UMS, Munich) in the semi-arid Cuvelai–Etosha Basin (CEB), Namibia. Results support the applicability of an in situ measurement system for the determination of stable isotopes in soil pore water. High spatial and temporal resolution was achieved in the study area with reasonable accuracy and measurements were in agreement with laboratory-based cryogenic vacuum extraction and subsequent cavity ring-down laser spectroscopic isotope analysis (CRDS, L2120-i, Picarro Inc.). After drift and span correction of the in situ isotope data, precision for over 140 measurements taken during two consecutive field campaigns (June and November 2014) was 1.8 and 0.48 ‰ for δ2H and δ18O, respectively. Mean measurement trueness is determined using quality check standards and was 5 and 0.3 ‰ for δ2H and δ18O, respectively. The isotope depth profiles are used quantitatively to calculate a soil water balance. The contribution of transpiration to total evapotranspiration ranged between 72 and 92 %. Shortly after a rain event, the contribution of transpiration was much lower, at 35 to 50 %. Potential limitations of such an in situ system are related to environmental conditions which could be minimized by using a temperature-controlled chamber for the laser spectrometer. Further, the applicability of the system using previously oven-dried soil material might be limited by physicochemical soil properties (i.e., clay minerals). Uncertainty in the in situ system is suggested to be reduced by improving the calibration procedure and further studying fractionation effects influencing the isotope ratios in the soil water, especially at low water contents. Furthermore, the influence of soil-respired CO2 on isotope values within the root zone could not be deduced from the data.

scholarly journals Grevillea trichantha, a third species with hairy flowers in the Triloba Group (Proteaceae: Grevilleoideae: Hakeinae) from the Marchagee Track, south-west Western Australia

Telopea ◽  
2021 ◽  
Vol 24 ◽  
pp. 303-309
Author(s):  
Peter Olde ◽  
Keyword(s):  
Western Australia ◽  
Rare Species ◽  
Conservation Priority ◽  
The Third ◽  
South West ◽  
High Conservation

Grevillea trichantha Olde, a rare species in the Triloba Group is described. It appears to be most closely related to another rare species, G. metamorpha Makinson and is more common, though its localised distribution still requires a high conservation priority. Grevillea trichantha is the third species in the Triloba Group in which the perianth is consistently, but not always uniformly, hairy. A short key differentiating the three species is provided.

A systematic revision of Draculoides (Schizomida: Hubbardiidae) of the Pilbara, Western Australia, Part I: the Western Pilbara

Zootaxa ◽  
2020 ◽  
Vol 4864 (1) ◽  
pp. 1-75
Author(s):  
KYM M. ABRAMS ◽  
JOEL A. HUEY ◽  
MIA J. HILLYER ◽  
RAPHAEL K. DIDHAM ◽  
MARK S. HARVEY
Keyword(s):  
New Species ◽  
Western Australia ◽  
Short Range ◽  
Sequence Data ◽  
Morphological Characters ◽  
Northern Australia ◽  
Systematic Revision ◽  
High Conservation ◽  
Semi Arid ◽  
First Descriptions

The schizomid fauna of mainland Australia currently comprises 60 species within seven named genera, of which five are endemic to the continent: Attenuizomus Harvey, 2000, Brignolizomus Harvey, 2000, Draculoides Harvey, 1992, Julattenius Harvey, 1992, Notozomus Harvey, 2000. Most Australian schizomids have been described from eastern and northern Australia, but there is also a significant subterranean fauna that has been found in hypogean habitats in the semi-arid Pilbara region of Western Australia. The vast majority of these species can be assigned to the genus Draculoides and this study is the first in a proposed series to revise this highly diverse genus. We treat the species found in the western Pilbara region, which includes 13 new species and 13 previously named species, using morphological characters and multi-locus sequence data. We also incorporate a molecular “mini-barcode” approach for COI, 12S and ITS2 to diagnose the new species. The new species are named: Draculoides akashae Abrams and Harvey, n. sp., D. belalugosii Abrams and Harvey, n. sp., D. carmillae Abrams and Harvey, n. sp., D. christopherleei Abrams and Harvey, n. sp., D. claudiae Abrams and Harvey, n. sp., D. immortalis Abrams and Harvey, n. sp., D. karenbassettae Abrams and Harvey, n. sp., D. mckechnieorum Abrams and Harvey, n. sp., D. minae Abrams and Harvey, n. sp., D. noctigrassator Abrams and Harvey, n. sp., D. nosferatu Abrams and Harvey, n. sp., D. piscivultus Abrams and Harvey, n. sp. and D. warramboo Abrams and Harvey, n. sp. We also provide the first descriptions of males of D. anachoretus (Harvey, Berry, Edward and Humphreys, 2008) and D. gnophicola (Harvey, Berry, Edward and Humphreys, 2008). All of the new species are subterranean-dwelling, short-range endemic species that occur in regions subject to mining activities, rendering them of high conservation significance. 

scholarly journals Livestock enclosures in drylands of Sub-Saharan Africa are overlooked hotspots of N2O emissions

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Klaus Butterbach-Bahl ◽  
Gretchen Gettel ◽  
Ralf Kiese ◽  
Kathrin Fuchs ◽  
Christian Werner ◽  
...  
Keyword(s):  
Sub Saharan Africa ◽  
N2o Emissions ◽  
Arid Environments ◽  
Current Estimate ◽  
Continental Scale ◽  
Livestock Population ◽  
Sub Saharan ◽  
Semi Arid ◽  
Over Time

Abstract Sub-Saharan Africa (SSA) is home to approximately ¼ of the global livestock population, which in the last 60 years has increased by factors of 2.5–4 times for cattle, goats and sheep. An important resource for pastoralists, most livestock live in semi-arid and arid environments, where they roam during the day and are kept in enclosures (or bomas) during the night. Manure, although rich in nitrogen, is rarely used, and therefore accumulates in bomas over time. Here we present in-situ measurements of N2O fluxes from 46 bomas in Kenya and show that even after 40 years following abandonment, fluxes are still ~one magnitude higher than those from adjacent savanna sites. Using maps of livestock distribution, we scaled our finding to SSA and found that abandoned bomas are significant hotspots for atmospheric N2O at the continental scale, contributing ~5% of the current estimate of total anthropogenic N2O emissions for all of Africa.

CONSERVATION OF RARE SPECIES PLANTS AND LICHENS IN SITU WITH PLANNED ANTHROPOGENIC ACTIVITIES: BASIC APPROACHES AND IMPLEMENTATION PRINCIPLES

2018 ◽  
Vol 12 (7-8) ◽  
pp. 38-45
Author(s):  
A. N. EFREMOV ◽  
N. V. PLIKINA ◽  
T. ABELI
Keyword(s):  
Rare Species ◽  
Technology Implementation ◽  
Technology Development ◽  
Anthropogenic Activities ◽  
Natural Habitat ◽  
Local Population ◽  
Main Stage ◽  
Social Risks

Rare species are most vulnerable to man-made impacts, due to their biological characteristics or natural resource management. As a rule, the economic impact is associated with the destruction and damage of individual organisms, the destruction or alienation of habitats. Unfortunately, the conservation of habitat integrity is an important protection strategy, which is not always achievable in the implementation of industrial and infrastructural projects. The aim of the publication is to summarize the experience in the field of protection of rare species in the natural habitat (in situ), to evaluate and analyze the possibility of using existing methods in design and survey activities. In this regard, the main methodological approaches to the protection of rare species in the natural habitat (in situ) during the proposed economic activity were reflected. The algorithm suggested by the authors for implementing the in situ project should include a preparatory stage (initial data collection, preliminary risk assessments, technology development, obtaining permitting documentation), the main stage, the content of which is determined by the selected technology and a long monitoring stage, which makes it possible to assess the effectiveness of the taken measures. Among the main risks of in situ technology implementation, the following can be noted: the limited resources of the population that do not allow for the implementation of the procedure without prior reproduction of individuals in situ (in vitro); limited knowledge of the biology of the species; the possibility of invasion; the possibility of crossing for closely related species that сo-exist in the same habitat; social risks and consequences, target species or population may be important for the local population; financial risks during the recovery of the population. The available experience makes it possible to consider the approach to the conservation of rare species in situ as the best available technology that contributes to reducing negative environmental risks.

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