Debbie Jewitt

• PhD
• Independent Researcher

Anticipating global change impact on natural vegetation, especially in poorly researched systems, requires an understanding of the environmental factors that most strongly influence the organisation of plant communities at different scales. The environmental relations of plant communities in the Drakensberg mountains of South Africa remain poorly r...

Africa's range-restricted subtropical-temperate coastal forested wetlands are facing interlinking threats of climate and anthropogenic pressures. We assessed their conservation status using the criteria of the International Union for Conservation of Nature (IUCN). Their total areal extent was hind-casted to the reference epoch 2000, followed by the...

This study forms part of the Natural Capital Accounting and Valuation of Ecosystem Services (NCAVES) project and builds on the compilation of pilot physical and monetary ecosystem services accounts for KwaZulu-Natal for 2005-2011. The analysis demonstrates the utility of ecosystem accounts – consistent with the System of Environmental Economic Acco...

Best practice guidelines for drones and wildlife

The loss of natural habitat resulting from human activities is the principal driver of biodiversity loss in terrestrial ecosystems globally. Metrics of habitat loss are monitored at national and global scales using various remote sensing based land-cover change products. The metrics go on to inform reporting processes, biodiversity assessments, lan...

Countries monitor their economic performance through the System of National Accounting (SNA), a standardised international methodology which delivers widely used indicators. While the SNA keeps track of man-made capital and goods and services, it does not keep track of natural capital. This has an important bearing for long term sustainability if n...

https://novumintelligence.com/2020/07/16/lessons-learned-from-regional-temporal-land-cover-mapping/

The use of drones in conservation

http://www.ee.co.za/article/the-use-of-drones-in-conservation.html# PositionIT, 7th August 2018. Drones, or unmanned aerial vehicles (UAVs), are rapidly changing the face of the conservation industry. They have the potential to revolutionise conservation and spatial ecology. At the core of conservation is the monitoring of species populations and...

Many regions of South Africa are prone to woody plant thickening. This can have an ecologically detrimental effect on the open savannas and grasslands. KwaZulu-Natal, a province on the east coast of South Africa, is currently experiencing an increase in both the density and distribution of Vachellia nilotica. This research aims to gain better insig...

Background: Systematic conservation planning aims to ensure representivity and persistence of biodiversity. Quantitative targets set to meet these aims provide a yardstick with which to measure the current conservation status of biodiversity features and measure the success of conservation actions. Objectives: The conservation targets and current e...

Habitat loss and climate change are primary drivers of global biodiversity loss. Species will need to track changing environmental conditions through fragmented and transformed landscapes such as KwaZulu-Natal, South Africa. Landscape connectivity is an important tool for maintaining resilience to global change. We develop a coarse-grained connecti...

Global change, specifically land cover change and climate change, are recognised as the leading drivers of biodiversity loss worldwide. Habitat loss has resulted in a loss of biodiversity and led to significant declines in species populations. Climate change is altering species distributions, ecosystem composition and phenology. Conservation planni...

Collective properties of biodiversity, such as beta diversity, are suggested as complementary measures of species richness to guide the prioritisation and selection of important biodiversity areas in regional conservation planning. We assessed variation in the rate of plant species turnover along and between environmental gradients in KwaZulu-Natal...

The paper evaluated the Landsat Automated Land Cover Update Mapping (LALCUM) system designed to rapidly update a land cover map to a desired nominal year using a pre-existing reference land cover map. The system uses the Iteratively Reweighted Multivariate Alteration Detection (IRMAD) to identify areas of change and no change. The system then autom...

South Africa is one of seven pilot countries involved in a global initiative called Advancing SEEA Experimental Ecosystem Accounting,1 led by the United Nations Statistics Division (UNSD) in partnership with the United Nations Environment Programme (UNEP) and the Convention on Biodiversity (CBD), with funding from the Government of Norway. Within S...

Land-cover change and habitat loss are widely recognised as the major drivers of biodiversity loss in the world. Land-cover maps derived from satellite imagery provide useful tools for monitoring land-use and land-cover change. KwaZulu-Natal, a populous yet biodiversity-rich province in South Africa, is one of the first provinces to produce a set o...

Land-cover change and habitat loss are widely recognised as the major drivers of biodiversity loss in the world. Land-cover maps derived from satellite imagery provide useful tools for monitoring land-use and land-cover change. KwaZulu-Natal, a populous yet biodiversity-rich province in South Africa, is one of the first provinces to produce a set o...

Conservation planning in the face of global change is still in its infancy. A suggested approach is to incorporate environmental gradients into conservation planning as they reflect the ecological and evolutionary processes generating and maintaining diversity. Our study provides a framework to identify the dominant environmental gradients determin...

This report is available from: http://biodiversityadvisor.sanbi.org/planning-and-assessment/experimental-ecosystem-accounting/ South Africa is one of seven pilot countries involved in a global initiative called Advancing SEEA Experimental Ecosystem Accounting,1 led by the United Nations Statistics Division (UNSD) in partnership with the United Nat...

The effect of sampling frequency on estimates of the rate of litter accumulation was determined for two South African sandy beaches. After initial cleaning, all manufactured items >10mm diameter were collected in alternating bouts of daily or weekly cleanups. Daily sampling collected 2.5 (range 2.1-3.4) times more litter items than weekly samples a...

The effects of burning on soil properties and landscape function were investigated in a long-term experiment comparing different burning strategies in a moist montane grassland. Total C, total N, total S, bulk density, plant-available nutrients, and soil acidity were determined in the top 200mm of soil, together with vegetation basal cover at the s...

South Africa's beaches are an important facet of the country's tourism potential. Coastal authorities spend on estimated R8 million each year cleaning beaches. More than 50 000 km of coastline is cleaned annually, with most effort focused on urban resort beaches, many of which are cleaned daily throughout the year. Less than 5% of clean-ups are per...

'Free' bags issued by supermarkets cost South Africans approximately R200 million a year in direct costs. Inappropriate disposal of these bags results in substantial additional economic and environmental costs. A questionnaire survey was used to assess the attitudes of consumers to the problem. Key findings were that all sectors of the sample commu...