Erwin J. J. Sieben- PhD
- Senior Lecturer at University of KwaZulu-Natal
Erwin J. J. Sieben
- PhD
- Senior Lecturer at University of KwaZulu-Natal
Writing a book on the wetland plants of South Africa
About
50
Publications
23,112
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634
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Introduction
I am Erwin Sieben and my interest is in vegetation ecology and plant functional ecology. My main research focus is on wetland vegetation and about how wetland plants are distributed on their 'island habitats' across the country of South Africa which has steep environmental and climatic gradients.
Current institution
Additional affiliations
January 2007 - December 2015
University of the Free State, Qwaqwa Campus
Position
- Professor (Associate)
Description
- Teaching Plant systematics and evolution (3rd year), Vegetation ecology (3rd year), Biostatistics (Honours), Restoration Ecology (Honours) and General Botany (1st year)
January 1998 - March 2001
January 2007 - December 2015
Education
January 1998 - December 2003
August 1990 - August 1995
Publications
Publications (50)
Mountainous regions typically harbour high plant diversity but are also characterised by low sampling intensity. Coarse-scale species distribution models can provide insights into the distribution of poorly sampled species, but the required bioclimatic data are often limited in these landscapes. In comparison, several environmental factors that var...
(1) Background: Depressional wetlands are highly vulnerable to changes in temperature and rainfall, affecting littoral vegetation, thus HydroGeoMorphic (HGM) wetland types. This study aimed to assess the utility of Sentinel-2A vegetation indices in enhancing delineation and sub-classify depressional HGM types. (2) Methods: We sampled 84 pairs of fo...
In this chapter, we present a hierarchical framework to consider wetlands and their ecosystem services in landscape planning. Wetlands are important in a landscape setting as they are intricately linked to the water cycle, and they provide many ecosystem services. Collectively, wetlands can be regarded as wet ecological infrastructure. Wetlands can...
Monitoring changes in the areal extent and geographic distribution of wetland vegetation has become more critical considering the impact of anthropogenic and climate changes. We compared the capabilities of the optical space-borne sensors Sentinel-2 and WorldView-3 (WV3) to distinguish between wetland and terrestrial vegetation for improved reporti...
Data for the article 'Components of plant species diversity along environmental gradients at various spatial scales in wetland environments of South Africa' Journal of Vegetation Science, November 2021
Wetland communities are shaped by high levels of stress, disturbance and competition. Using South African palmiet wetlands as a case study (Prionium serratum dominated valley-bottom wetlands), we explore whether autogenic or allogenic succession is the dominant process driving community dynamics in valley-bottom wetlands in drylands. Several wetlan...
Original article: https://doi.org/10.17159/sajs.2022/11540
Errors that appear in the Discussion of the Research Article by Sieben et al. are corrected here. Dr Graham Harding (Registered PCO, Invader Plant Specialists (Pty) Ltd) is acknowledged for drawing the authors’ attention to these errors.
Page 4, right column, section ‘(1) The choice of he...
An inventory of wetland vegetation across the country generated a list of the most common invasive alien plants across South Africa. Many of the plants on that list do not correspond with the priorities in the programmes for alien control across the country, as they are not listed on a government produced list that guides the priorities for alien c...
Wetlands form across a wide range of landscapes in response to landform development over extended timescales. From this perspective, the overall physical structure and hydrology of wetlands is determined by climate and geomorphological factors. These provide the framework for multiple local hydrological, physiochemical, and biotic processes and int...
Questions
Effective conservation planning of wetlands requires an understanding of the drivers of wetland diversity at different spatial scales. This study addresses the question: Which environmental variables are most responsible for the turnover of wetland plant diversity at various spatial scales (beta and gamma diversity)? Additionally, how doe...
Depressional wetlands are highly vulnerable to changes in land surface temperature and rainfall but little is known about their responses to future climate change. This study assessed the variation in edaphic factors between wetlands and along their littoral gradients to detect the boundary between the endorheic wetlands and upland zones. A sample...
The assessment of regional diversity of wetlands at a country-wide scale can be challenging for data-poor countries. However, plant species records and datasets can provide insight in the drivers and geographic extent of the possible diversity in wetland flora at a country-wide scale. The species pool concept was applied to wetland plants in South...
Understanding montane wetlands and their functioning is essential for biodiversity conservation and sustainable provision of ecosystem services. Plant functional traits represent species adaptations to specific environments and are considered the key mechanism by which individual species contribute to the functioning and subsequent provision of eco...
Question
Plant communities will change along environmental gradients, even in ‘azonal’ vegetation such as wetlands. It is hypothesised that functional community composition of wetland vegetation changes along a natural gradient from a dry low‐lying area to a wet high‐lying area. We wanted to know how the functional groups that make up wetland plant...
Available for download from
http://wrcwebsite.azurewebsites.net/mdocs-posts/establishing-remote-sensing-toolkits-for-monitoring-freshwater-ecosystems-under-global-change/
EXECUTIVE SUMMARY:
BACKGROUND
Freshwater ecosystems are globally considered one of the most threatened ecosystems in the world. More than > 85% of wetlands are estimated to be...
This study characterises the Afromontane wetlands existing along the altitudinal gradient in Lesotho in terms of plant functional traits and composition.
The description and classification of wetland vegetation is important for water resource management and biodiversity conservation as it provides an understanding of the wetland vegetation–environment relationships and information to interpret spatial variation in plant communities. This study discusses the vegetation of the palustrine wetlands of L...
Van Deventer, H., Smith-Adao, L., Mbona, N., Petersen, C., Skowno, A., Collins, N.B., Grenfell, M., Job, N., Lötter, M., Ollis, D., Scherman, P., Sieben, E. & Snaddon, K. 2018. South African National Biodiversity Assessment 2018: Technical Report. Volume 2a: South African Inventory of Inland Aquatic Ecosystems (SAIIAE). Version 3, final released on...
Van Deventer, H.; Smith-Adao, L.; Collins, N.B.; Grenfell, M.; Grundling, A.; Grundling, P-L.; Impson, D.; Job, N.; Lötter, M.; Ollis, D.; Petersen, C.; Scherman, P.; Sieben, E.J.J.; Snaddon, K.; Tererai, F. & Van der Colff, D. 2019. South African National Biodiversity Assessment 2018: Technical Report. Volume 2b: Inland Aquatic (Freshwater) Compon...
Classification and description of wetland vegetation provides an understanding of the wetland vegetation–environment relationships, as well as their spatial variation and information for water resource management and biodiversity conservation. In this study, the montane palustrine wetland vegetation types of the Maloti-Drakensberg region and surrou...
Aim
Why some lineages are species‐rich and widespread, while others are species‐poor and localized, is a fundamental question in evolutionary biology and ecology. Diversification and range expansion relate to lineage‐specific niche characters, but this link has seldom been quantified across multiple lineages and environments. This study explored th...
Urban forests are under increased pressure from invasion by exotic (alien) species. The vegetation present in the matrix of urban sites is a rich source of alien invasive propagules, which increases the risk of alien invasion in forests within an urban space, leading to a decline in indigenous species. Therefore, determining the distribution patter...
In ‘zonal’ vegetation, climatic factors are the main influence on growth and performance and the climate determines the vegetation type completely, which makes this vegetation dominant in the landscape. If vegetation is ‘azonal’ however, local stresses are assumed to have an overwhelming influence on plant performance and climatic influences will b...
In this study, the montane palustrine wetland vegetation types of the Maloti-Drakensberg region and the surrounding areas are discussed based on a phytosociological approach.
The typology of wetlands provides important information for both water resource managers and conservation planners. One of the most important aims of allocating wetlands to a certain type or class is to provide information about the ecosystem services that the wetland provides. There are two main approaches towards wetland classification. Firstly,...
The common wetland vegetation types categorized as temperate grassy wetlands have tall or medium tall graminoids that are found in the Highveld and other grassland areas in South Africa, but can extend into other biomes. The data on temperate grassy wetlands were extracted from a nationwide wetland vegetation database, consisting partly of historic...
A description of wetland habitats on nutrient-poor sandstone and quartzite substrates across South Africa is given. Most of these are situated in the Fynbos Biome and are dominated by sclerophyllous shrubs but there are some sedge-dominated vegetation types as well as geographical outliers found in Pondoland, the Kamiesberg, the Mpumalanga escarpme...
Studies of community assembly focus on finding rules that predict which species can become member of a plant community. Within a community, species can be categorized in two ways: functional groups classify species according to their functional traits, whereas generalized guilds group species based on their (co-)occurrence, spatial distribution and...
A survey of vascular plant species occurring in various wetland habitats in South Africa has been generated by supplementing the species list from a vegetation survey with a herbarium checklist and this list of wetland species is compared with the overall flora of South Africa. About 18.8% of all the South African species occur in wetlands and abou...
In this paper, the wetland vegetation types of subtropical wetlands occurring in South Africa are discussed. The South African National Wetland Vegetation Database targeted the collation of all available wetland vegetation data consisting of species composition, Braun-Blanquet cover-abundance data and the relevant environmental parameters. A subset...
Knowledge and understanding of wetland vegetation is an important component of sound wetland ecosystem management as vegetation represents a link between biota and ecosystem processes. In this paper, the saline wetlands of the arid inland regions of South Africa are discussed. Even though these wetlands contain water only occasionally they are amon...
This paper describes grass lawn wetlands, which are wetlands subjected to dynamic conditions, particularly highly fluctuating water tables that regularly drop deep below the ground surface. This occurs mostly in floodplain wetlands, as well as in wetlands in semi-arid regions or coastal plains. These wetlands are often dominated by short lawn grass...
Zonation patterns of riparian vegetation have been sampled and described in mountain streams in two catchments in the Hottentots-Holland Mountains, Western Cape, South Africa. Six main vegetation types that differ in structure and species composition, are dominant along these river banks: Aquatic vegetation, Wetbanks, Palmiet, Scrub, Forest and Shr...
A classification system is described that was developed for inland aquatic ecosystems in South Africa, including wetlands. The six-tiered classification system is based on a top-down, hierarchical classification of aquatic ecosystems, following the functionally-oriented hydrogeomorphic (HGM) approach to classification but incorporating structural a...
The shore of Lake St Lucia in the vicinity of Catalina Bay, in the southern part of the lake, receives freshwater input as surface and groundwater seepage from the adjacent elevated coastal plain. Vegetation, water quality and landform were recorded on the lakeshore and on the dry lakebed near one of these seepage zones. This was done along a gradi...
Assessing the ecological outcomes of wetland rehabilitation activities is an important need recognised by the ‘Working for Wetlands’ programme in South Africa. An assessment of ecological response was conducted in the Killarney and Kruisfontein wetlands, KwaZulu-Natal, in 2005 prior to rehabilitation in 2006, and again in 2011 and 2012, respectivel...
This project aims towards the development of a database with detailed species composition data for vascular plants as well as basic environmental information that can be queried and by which wetland communities across the country of South Africa can be compared in a standardized way. It also includes a classification of wetland vegetation types tha...
The assumption that ecosystems with similar emergent properties consist of similar functional groupings of plant species is tested by comparing three peatlands from different bioregions across South Africa. They are Mfabeni Swamp in the subtropical coastal region, Wakkerstroom on the inland plateau, and Goukou wetland in the Winter Rainfall region...
Wetland rehabilitation planning needs to take into account many different aspects of the wetland and its context. In South
Africa, much emphasis is placed on the delivery of ecosystem services, poverty relief and skills development for those involved
in labour-intensive rehabilitation measures. A framework is presented that facilitates decision-mak...
A survey was conducted on the wetlands in me South African section of the Maloti-Drakensberg Transfrontier Park (MDTP), along altitudinal gradients from the foothills to the summit plateau in six different catchments. Environmental indices of soil wetness, texture and organic contents of the soil were determined to relate wetland community types to...
A survey of 93 wetlands in six catchments across the Maloti-Drakensberg is used to assess the distribution of plant functional
types across altitudinal and wetness gradients. Altitudes range from 1,000 to 3,200m a.s.l. Within each catchment, the wetlands
were selected to cover the complete range in altitude and wetland types. In each of the selecte...
Question: How can vegetation gradients be described in riparian zones located in a species-rich mountain range and how do these gradients explain the variation found in the vegetation?
Location: Hottentots Holland Mountains, Western Cape, South Africa.
Methods: Three gradients (geographic, longitudinal, lateral) were defined to describe the complex...
A Red data list assessment of selected wetland plant species in Southern Africa.
Found online:
http://books.google.co.za/books?id=0ajCGOjF1h8C&pg=PA86&lpg=PA86&dq=Erwin+Sieben&source=bl&ots=e50mb_Iwvz&sig=iuzJ1UXzDaGo80D6KVYnTAHWx8c&hl=en&ei=3Np7S-TxINT1-Qawv9jQBQ&sa=X&oi=book_result&ct=result&resnum=5&ved=0CBAQ6AEwBDgK#v=onepage&q=Erwin%20Sieben&...
APONOGETON FUGAX, A NEW SPECIES ENDEMIC TO THE CAPE FLORAL REGION, SOUTH AFRICA
When considering revegetation strategies for particular restoration projects, data on community composition and structure should, whenever possible, be obtained from reference sites. Revegetation is an important restoration strategy especially since riverbanks that have been cleared of alien vegetation are extremely susceptible to erosion. The pres...
Seepages occurring at high altitudes in the Hottentots Holland Mountains (HHM) (Western Cape Province, South Africa) were subject to a phytosociological survey. Relevé sampling method and classification procedures of the floristic-sociological (Braun-Blanquet) approach as well as numerical data analyses (numerical classification and ordination) wer...
Thesis (Ph. D.)--University of Stellenbosch, 2003. Includes bibliographical references.
Questions
Questions (4)
Joseph Tainter taught us in 1988 that civilizations have a limited lifespan due to the marginal returns on investments declining over time. This can be regarded as a theoretical issue that has relevance for archaeologists, but ever since Jem Bendell wrote his paper on deep adaptation in 2018, I wonder whether we as conservationists and specialists in sustainable development should also consider this in how we approach our discipline and what kind of research questions we should address if our civilization is indeed already in decline ?
I conducted a partial CCA analysis in Canoco 5 on a dataset with environmental variables belonging to three distinct spatial scales. When doing variation partitioning it is normal to get some overlap in variation that is accounted for by two or three different components (or spatial scales). This can then be used to illustrate the overlap graphically by overlapping circles (although it is very difficult if not impossible to get it up to the right scale). What does it mean however if the programme returns a negative value for overlap and how do I interpret that ?
I am trying to get a grasp on the dynamics of wetland vegetation between wet and dry years. I started monitoring vegetation in a wetland during a dry spell but from the preceding wetter years I have only photographs, even though individal species are recognizable from these photographs. Are there ways in which to use these photographs still in a systematic manner ?
In Canoco 4.5 you could treat nominal variables in a separate way from numerical variables by having each category of a nominal variable assigned a separate column in the environmental data file and then assigning these nominal variables within the programme of Canodraw the status of 'nominal variables'. In Canoco 5.0 I cannot find this function any more and nominal variables are drawn by means of arrows just like all the other variables.
