Browsing by Author "Zaloumis, Nicholas Paul"
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- ItemOpen AccessHow successful is grassland restoration after removal of pine plantations on the eastern shores of Lake St Lucia?(2008) Zaloumis, Nicholas Paul; Bond, William J; Hoffmann, TimmThe coastal grasslands that occur along the Eastern Shores of Lake St. Lucia are rich in plant species, including endemics. These grasslands in North KwaZulu-Natal, South Africa, are remnants of a severely threatened vegetation type. Large portions of the Eastern Shores have been utilized for commercial pine plantations over the last 50 years; however these have been removed over the last 17 years. It is therefore important that efforts to restore grasslands that have been previously afforested stands of pines are successful. These grassland systems are fire driven and therefore many plants have adapted to these conditions by having massive storage organs below the ground. Using several response variables I was able to assess the effects of plantations on alpha- and beta-diversity and functional traits of forb and other grassland species and attempted to determine whether these disturbed grassland were returning to their original state. A high level of community heterogeneity was found at both scales for natural vegetation, while more homogenous, species low patterns were seen in post-plantation sites. Most notable was the large number of missing resprouting species in pine sites and that, in contrast to forest rehabilitation studies, no evidence for succession was found. The implication of this is massive as grassland rehabilitation may be a lot harder than was previously thought. It is likely that the fire adapted forb species are bad colonizers and have struggled to return to disturbed sites. These grasslands are therefore susceptible to activities that remove or eliminate the considerable amount of below ground biomass from the soil, and these sorts of disturbances should be avoided. Active rehabilitation methods will be required if any progress is going to be made and until such methods are effective considerable effort should be made in conserving the remaining grasslands that we have left and promoting its pharmaceutical, horticultural and societal value.
- ItemOpen AccessIUCN red listing of marine macroalgal species : a South African case study(2008) Zaloumis, Nicholas Paul; Bolton, John JThe IUCN Red List of Threatened Species is considered an important tool for conservation. However most evaluations have been restricted to terrestrial species and marine species are underrepresented. In contrast to terrestrial environments, the marine environment differs in dispersal restrictions and the difficulty of sampling. This has made it hard to gain sufficient knowledge and therefore literature on the majority of species and makes it difficult to assess the effects of disturbance on species and environments. Marine species are thought to be greatly affected by over-exploitation and by-catch. However, a large proportion of the oceans diversity is situated on the coastal region, particularly as benthic organisms. These environments are considered to be a high risk of disturbance and habitat alteration due to human activities and therefore indicate that habitat loss could result in many species disappearing. The seaweed taxa have only had a total of 75 species listed. Besides being a taxonomically difficult group, there is also very little relevant literature available for effective IUCN evaluations. This study looks at assessing (i) the effectiveness, to date, of identifying seaweed species at risk of extinction, including any fallbacks or complications that seaweed species may face during an IUCN evaluation, (ii) what procedures need to be followed during the process of the evaluation, especially when limited data is available and (iii) what species characteristics could be used to identify candidates for such an assessment. This was done using two methods, firstly by reviewing what seaweed species have been currently listed and the secondly through the form of a case study using three South African endemic species with restricted distribution. IUCN threat criteria fulfil led by species and the threat categories that they achieved were related to knowledge of species distribution for seaweed species. There was an increased degree of certainty when more literature or knowledge was available and when targeted surveys for individual species were undergone. Comprehensive studies on species population dynamics and natural population fluxes were also useful. Seaweed species with restricted dispersal are most likely to make it onto the IUCN list. There is a need for seaweed scientists to come up with a solution to tackle this lack of information. Overall the IUCN evaluation process should not need to adapt for seaweed species and that evaluations have the potential to be used as indicators of ecosystem change for a region.
- ItemOpen AccessSouth African grassland ecology and its restoration(2013) Zaloumis, Nicholas Paul; Bond, William J; Kirkman, KevinThe aim of this study is to investigate how human related disturbances affect mesic grasslands. I identified what was lost from the system after a disturbance and what biological constraints ecologists and managers will face when approaching their restoration. I then investigated biological limitations to grassland restoration by attempting species reintroduction into secondary grasslands and exploring the interaction between grasses and forbs.