David Gallacher

David Gallacher
NWANT Drought Resilience Adoption & Innovation Hub

PhD Plant Genetics

About

62
Publications
35,425
Reads
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423
Citations
Additional affiliations
August 2019 - present
The University of Sydney
Position
  • Research Associate
September 2003 - July 2019
Zayed University
Position
  • Professor (Associate)

Publications

Publications (62)
Article
Full-text available
Aerial surveillance can detect visual, heat, vegetation, and atmospheric changes over time, and aerial transport can facilitate the collection of air, liquid and solid samples for later analysis in laboratory conditions. Drones have great potential for urban environmental analysis, but also raise valid concerns about safety, security and privacy. G...
Research
Full-text available
Protected rangelands in desert shrub habitats are typically large spaces with low biodiversity and sparse biomass. These conditions are optimal for monitoring by drone, since alternatives are prohibitively expensive. Over 600 plants were photographed at 2, 6 and 20 mm ground sampling distances. Each was identified in situ by a resident botanist, an...
Article
Camel grazing is recognized as a primary cause of ecological degradation in the UAE. A study of perennial plant species <1 m in height was conducted along a fence separating continuously camel grazed land from land in which camels had been replaced by oryx and gazelle species for 5 years (Al Maha). Vegetation regeneration in Al Maha in the absence...
Article
Germination in the arid rangelands of the UAE occurs as an ‘event’ following a mid-winter to spring rainfall. A fence line study of germination events was conducted in 2005 and 2006 to identify the response to differential grazing regimes. Fifty-six 1m2 seedling plots were destructively sampled each season. Heavy grazing reduced species richness an...
Article
Full-text available
Wetland species commonly exhibit a range of strategies to cope with water stress, either through drought tolerance or through avoidance of the period of limited water availability. Natural populations provide a genetic resource for ecological remediation and may also have direct economic value. We investigated the effects of drought stress on the s...
Article
The role of seed mucilage in the moist environments of monsoonal subtropics is poorly understood. We studied germination of six forb species from subtropical monsoonal China. Mucilage presence had little to no effect on G%, except for a significant decline for the large-seeded Prunella vulgaris. Dark treatments reduced G% for all species, while the...
Article
Coastal desert vegetation of the Arabian Peninsula is almost entirely dominated by halophytes. Natural populations provide a genetic resource for ecological remediation and may also have direct economic value. High intrapopulation variation of seed traits is presumed to increase population persistence in the unpredictable climatic conditions of thi...
Article
Full-text available
Plant species of the Brazilian Caatinga experience seasonal wet and dry extremes, requiring seasonally different leaf characteristics for optimizing water availability. We investigated if Croton blanchetianus Baill exhibits leaf morphoanatomical traits across seasons and positioning in sunlight/natural shade. Leaves of ten 1-3 m tall plants in full...
Article
Rehabilitation of coastal vegetation is reliant on the successful establishment of halophytic seedlings. Seed germination variation among populations of two desert halophytes, Arthrocnemum macrostachyum and Suaeda vermiculata, was assessed under seven salinity levels from 0 to 1000 mM NaCl. recovery of germination in seeds previously exposed to sal...
Article
Farm Policy Journal (Australian Farm Institute) - Agricultural data is diverse, collected for many reasons, stored on many servers, and arranged in many formats. Farms are complex ecosystems anchored in physical space, but their data space is evolving with the drive to improve resource management. In this article I will argue that agricultural data...
Article
Full-text available
The Himalayan region is particularly susceptible to biodiversity loss because it is ecologically rich, highly susceptible to climate change and natural hazards, and its governance is fragmented across multiple inter- and intra-national boundaries. Citizen reporting tools might provide an impetus for improving information-based management of wildlif...
Article
Mounds constructed by plateau zokors, which is widely distributed in alpine meadows significantly modified plant community structure. However, the variations of plant community structure under the disturbance of plateau zokor-made mound are less concerned. Therefore, we investigated the responses of plant community on zokor-made mound of different...
Chapter
Full-text available
Increasing water scarcity and soil salinization call for more diversified agricultural production systems that have the potential to sustain in marginal environments. Perennial forage grasses have been developed to replace conventional forages for the development of livestock sector in the Gulf and African regions. Perennial forage crops are known...
Article
Full-text available
As habitats change, species with higher intraspecific variation have more resources to adapt. Medicinal plants in the Himalayas are increasingly threatened by climate change and other anthropogenic influences. The intraspecific variation within and among 17 populations of the high-elevation herb Trillium govanianum Wall. ex D.Don was studied as an...
Article
Understanding variation of seed germination in wild populations can assist restoration projects through improved seed source selection. Recruitment of artificially distributed seed can be improved by selecting for suitable dormancy and germination characteristics. We investigated seed germination and emergence responses of three Astragalus sieberi...
Article
Regeneration of native species is the first priority for biodiversity conservation and restoration. To this end it is key to have seeds properly conserved in seed banks and knowledge of seed longevity and/or dormancy alleviation at different storage time intervals. In addition, understanding germination response of the stored seeds to environmental...
Article
Haloxylon salicornicum (Moq.) Bunge ex Boiss. is a suitable species for desert and coastal restoration for its forage production and dune stabilization. Inter-population variation of seed parameters has previously received little attention. Variation in seed germination response to drought and salinity stress was evaluated for three Kuwaiti populat...
Article
Species that can germinate under low water potential are likely to have greater utility for fodder production and restoration in arid habitats. We investigated seed germination response of four native grass species (Panicum acuminatum, Panicum turgidum, Pennisetum divisum and Polypogon monspeliensis) to five osmotic potentials (0, −0.3, −0.6, −0.9...
Article
Germination timing is highly regulated in short-lived plant species since it strongly influences recruitment success of vegetation. In deserts, the spatiotemporal distribution of plant-available water is highly episodic and unpredictable, making winter months more favorable for seed germination when other abiotic conditions co-occur. We hypothesize...
Article
Full-text available
Propagation and conservation of desert plants are assisted by improved understanding of seed germination ecology. The effects of dry-storage on dormancy and germination were studied in seven desert legumes. Mature seeds were collected in summer 2017 and germinated within one week of collection (fresh) and after six months (dry-storage) under two te...
Article
Knowledge of optimal conditions for germination facilitates more efficient practices, such as fodder production and restoration. We assessed seeds of three grass species, harvested in winter and summer 2018. Germination ability was assessed under two night/day temperature regimes (15ºC/20ºC, 20ºC/30°C) and two photoperiod regimes (0, 12 hours light...
Chapter
Increasing water scarcity and soil salinization call for more diversified agricultural production systems that have the potential to sustain in marginal environments. Perennial forage grasses have been developed to replace conventional forages for the development of livestock sector in the Gulf and African regions. Perennial forage crops are known...
Article
Deverra triradiata is an aromatic perennial shrub distributed in coastal arid regions. In the present study, we tested the effect of umbel order on seed weight, germination, and germination requirements for temperature and light. Germination rate was strongly affected by umbel order and photoperiod but not by thermoperiod. Seed mass also declined s...
Article
Desert plant species commonly use seed dormancy to prevent germination during unfavorable environmental conditions and thus increase the probability of seedling survival. Seed dormancy presents a challenge for restoration ecology, particularly in desert species for which our knowledge of dormancy regulation is limited. In the present study the effe...
Article
Maintaining a viable seed bank throughout the germination season is considered very important for plant recruitment in desert environments, where environmental conditions are unpredictable. Seeds from fully matured Seidlitzia rosmarinus Bunge ex Boiss and Halothamnus iraqensis Botsch. were collected in December 2016, then April, June, and September...
Article
Full-text available
Trillium has fascinated the botanical world with its peculiar biology and high medicinal value. The genus appears in North America and Asia, and is widely used for traditional medicine on both continents. Medicinal value has been validated recently through the isolation and ex situ testing of constituent compounds. This study reviews biology, medic...
Article
Trillium has fascinated the botanical world with its peculiar biology and high medicinal value. The genus appears in North America and Asia, and is widely used for traditional medicine on both continents. Medicinal value has been validated recently through the isolation and ex situ testing of constituent compounds. This study reviews biology, medic...
Article
Hyper-arid rangeland vegetation is typically dominated by large woody species which are often overlooked in herbivory studies. Long-term responses of tall shrub populations to herbivory change are poorly understood in the Arabian Peninsula. Population and size of 1559 individuals from four shrub species were assessed over an 11-year period under tw...
Article
Calligonum comosum L’Hér is a perennial evergreen shrub that produces dimorphic fruits of distinctly yellow or red colour. The species is found on sand dunes of the Middle East, is valued as a highly palatable livestock feed that survives extreme drought, and is suitable for desert restoration of non-saline sandy soils. The association of fruit col...
Article
Full-text available
Urban developments affect neighbouring ecosystems in multiple ways, usually decreasing native biodiversity. Arabian arid rangeland was studied to identify the primary causes of biodiversity variation. Al Marmoum is a 990 km2 area on the urban edge of Dubai, designated for ecological ‘enhancement’ and outdoor recreational use. The area lacks histori...
Chapter
Proof of long-term vegetation change in arid rangelands is often insufficient to influence policy, even when the change is clear to ecologists. Drones provide a way to collect unbiased evidence of plant spatiotemporal distribution at a dramatically reduced cost for the scales needed in these habitats. Assessment of phytomass spatial distribution by...
Conference Paper
Full-text available
Hyper-arid rangeland vegetation is typically dominated by large woody species which are often overlooked in herbivory studies. Knowledge of long-term large shrub population responses to change in browsing system in the Arabian Peninsula has been anecdotal. Population and size of 1559 individuals from four shrub species were opportunistically assess...
Article
We investigated the dimorphic perianth colour of Salsola vermiculata and its association with seed germination percentage, interactions with temperature, light, salinity and recovery from prior salinity exposure. Seeds with and without pink and yellow perianth were incubated at three thermal regimes, two photoperiods, and five salinity levels. Germ...
Article
Full-text available
Options for environmental management have improved dramatically over recent years. Sensors for air and water pollutants, and subsets of the elec­tromagnetic spectrum, have become smaller, cheaper, and more bundled into comprehensive units. Aerial sensor platforms have also expanded in the form of low-altitude unmanned aerial vehicles (micro-drones)...
Article
Full-text available
Aims To determine if the germination response of desert plant species to a period of aerial storage in field conditions (i.e. mature seeds that remain attached to the parent plant) is comparable to seeds harvested at maturity and stored in ambient laboratory conditions, to better understand the role of aerial seed bank in the germination ecology of...
Article
Full-text available
Salsola schweinfurthii is a perennial branched halophytic shrub that inhabits arid environments in and around the Arabian Peninsula. Its tolerance to extreme drought renders it suitable for urban arid landscaping. Germinability of intact and de-winged seeds (winged perianth removed) was determined under two photoperiods (0 and 12 hours light per da...
Conference Paper
Full-text available
Ecological monitoring in arid rangelands is highly suited to the use of low-altitude aerial imagery captured by drone, due to the habitat consisting of large areas with low biomass and biodiversity. Adoption of the technology requires broad expertise in ecology, drone hardware, and data interpretation, usually by a very small team or even an indivi...
Method
Full-text available
Series of workshops presented to the Drones for Good / Robotics for Good competition, Internet City, Dubai
Conference Paper
Full-text available
Traditional ecological monitoring of arid rangelands is labor intensive due to large areas involved, and high spatial variation in biodiversity distribution. The recent emergence of micro-drones (unmanned aerial vehicles) provides a new tool that has the potential to replace much of the monitoring currently done at ground level or by satellite and...
Article
Full-text available
Movement behavior of ungulates within a mid-sized arid rangeland reservation has implications for both conservation management and tourism. In this qualitative study, one male and one female Arabian oryx were tracked each 15 minutes for eight months using GPS collars in the 226 km 2 Dubai Desert Conservation Reserve. Results were consistent with wi...
Conference Paper
Full-text available
Statement of the Problem: Arid rangelands throughout the Middle East / North Africa (MENA) region are currently managed without clear information of long term trends in vegetation, stocking rates, or ecological health. It is often stated that rangelands suffer from overgrazing and excess water extraction, but there is a lack of reliable historical...
Article
Full-text available
Recruitment frequency of Prosopis cineraria in the United Arab Emirates is poorly understood, though heavy browsing by camels is often assumed to be a limiting factor. Macromorphological characteristics were recorded at eight locations from the northern United Arab Emirates. Tree size (canopy diameter, trunk diameter, and tree height) showed confor...
Article
Full-text available
Since the launch of a national initiative to equip all UAE federal tertiary students with iPads in 2012, there has been considerable discussion among UAE academics on the adoption of touch-screen portable devices. In contrast, there has been almost no discussion on the impact of massive open online courses (MOOCs) to higher education. International...
Conference Paper
Full-text available
Higher education in northern America is witnessing an unprecedented level of innovation, epitomized loosely through massive open online courses (MOOCs). The Australian Trade Commission has stated that the world's higher education system is disaggregating, with strong implications for the international student market. A United Kingdom White Paper ag...
Article
Full-text available
In recent years there has been a large increase of Higher education options in the United Arab Emirates. Emirati school leavers must choose among newly established institutions that provide unproven qualifications, at the same time as their society undergoes a rapid transformation. Online surveys were administered to female Emirati students in the...
Chapter
Over the last 35 years land management and farmer lifestyles have changed dramatically on the rangelands of the United Arab Emirates. The human relationship with rangelands has moved from subsistence to a secondary income or hobby. Both ecological health and indigenous knowledge of rangelands are in decline. Large areas of the inland desert of the...
Article
Full-text available
Session S 12 – Livestock and range management Over the last 35 years land management and farmer lifestyles have changed dramatically on the rangelands of the United Arab Emirates. The human relationship with rangelands has moved from subsistence to a secondary income or hobby. Both ecological health and indigenous knowledge of rangelands are in dec...
Technical Report
Full-text available
The United Nations Educational, Scientific, and Cultural Organization (UNESCO), has made aware the threatening yet continuing effects of desertification. In addition to causing land degradation, desertification has an immense impact on the ecological system. The International Year of Deserts and Desertification in 2006 (IYDD) has raised awareness t...
Article
Full-text available
Grazing of the Dubai inland desert has changed substantially over the last cen-tury, and particularly over the last three decades. Populations of oryx, ostriches and gazelles have been replaced by an increased camel herd, which is at least 2.5 times historical levels. Camel grazing patterns differ to smaller herbivores, affecting plant species comp...
Article
Full-text available
Trials were conducted by co-operators across the country over a number of years on a wide range of crops, including Asian cucurbits (melons and gourds) and kabocha, burdock, daikon, kailaan, taro, Japanese bunching onion, sweet potato and okra. Much verification of the information collected by the cooperating researchers from the various research a...
Article
Full-text available
Purpose, requirements, and application of morphological descriptors for use in a sugarcane germplasm collection are reviewed. Such descriptors could be used to verify the identity of cultivars, and as a measure of genetic distance. Verification of cultivar identity is essential in routine plant breeding and associated research. Genetic distance est...
Article
Full-text available
Genotypic, environmental, interaction, and error variances were studied for each of 24 qualitative and 142 quantitative morphological characters. Data were collected in 3 character sets: vegetative macromorphological, inflorescence, and epidermal. Broad-sense heritability was estimated for quantitative characters, and variance components were estim...
Article
Full-text available
No internationally accepted system of describing sugarcane cultivars has ever emerged, despite repeated attempts. An internationally adopted descriptor set would enable cultivar label maintenance both within and among research stations, and enable an international measure of genetic distance. An optimum morphological descriptor set was formulated a...
Article
Full-text available
Verification of cultivar identity is essential in routine plant breeding and associated research. The current study aimed to determine if scoring of isozyme phenotypes resolved with starch gel electrophoresis would provide a cheap, useful method of identifying sugarcane clones. One hundred Saccharum spp. hybrid clones selected at random from the Bu...
Thesis
Full-text available
An optimised descriptor set is essential for the maintenance of germplasm collections and the efficient exchange of material among organisations. No such descriptor set has been accepted internationally for sugarcane. The set need not enable a complete classification of germplasm to be of use to plant breeders. It could serve two main purposes with...

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Projects (11)