Conference presentations

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https://hdl.handle.net/20.500.12143/6813

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Browsing Conference presentations by Author "Alkalei, Osama"

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    Developing fixed-point photography, methodologies for assessing post-fire mountain fynbos vegetation succession as a tool for biodiversity management
    (2019-08-21) Alkalei, Osama; Knight, Richard; Harebottle, Doug
    Areas of high biodiversity and complex species assemblages are often difficult to manage and to set up meaningful monitoring and evaluations programmes. Mountain Fynbos is such an ecosystem and in the Cape of Good Hope (part of the Table Mountain National Park) plant biodiversity over the last five decades has been in decline. The reasons are difficult to speculate on since large herbivores, altered fire regimes and even climate change could be contributors to this decline, which has been quantified using fixed quadrats and standard cover abundance estimates based on a Braun-Blanquet methodology. To provide more detailed data with more resolution for identifying ecological processes, Fixed-Point Repeat Photography has been presented as a management solution. However, photography remains a difficult method with which to standardise subjects and has certain operational limitations. These include: weather conditions (poor visibility results in poor images), camera resolution (a low resolution will underestimate the number of small plant, or amount of flowers and fruits/seeds), shadows and image bright spots result in an effective loss of data. Also, photography will always have depth of field problems and perspective distortions. The aim of this study was to develop an effective method of fixed-point photography that overcomes these limitations to assess post-fire Mountain Fynbos succession. Using the highest resolution Digital Single Lens Reflex Camera (Canon 5Dsr) and a 45 mm tilt and shift lens, three images, each 51 Megapixel in size,were taken to expand the camera’s field of view horizontally and vertically since the camera was orientated to produce portrait images. The images were then processed and enhanced using two modern computer programmes (Photoshop and Lightroom) that stitched these images into one and to apply radiometric (colour balance) and geometric corrections (so that images taken at different times can be overlaid). By repeating this imagery at fixed points using marked out quadrats (3 × 2 m) over different seasons, a large amount of data relating to species richness, structural assemblages and phenological characteristics can be obtained. Such data could include monitoring individual plants, e.g. their growth rates, leaf development, flowering and seed production through to their senescence and death. Use of these enhanced photographic methods for monitoring and evaluation should improve the ability to better manage complex and species rich ecosystems. A video has been prepared to demonstrate the methods developed in this study: https://www.youtube.com/watch?v=sdK3U-49Ezg&t=2s