Coastal Dune Forest Rehabilitation:A Case Study on Rodent and Bird Assemblages in Northern Kwazulu-Natal, South Africa.

In: Coastal Dunes: pp.103-115. DOI: 10.1007/978-3-540-74002-5_7 .


Coastal dune forests in northern KwaZulu-Natal, South Africa, are continually exposed to natural and man-induced disturbances that usually initiate ecological succession (van Aarde et al. 1996a; Mentis and Ellery 1994). This succession is associated with temporal and spatial changes in vegetation structure that influence habitat suitability and ultimately the structure of vertebrate communities living there. For example, in the case of birds, we know from studies conducted elsewhere that species richness and diversity correlates with vegetation structural heterogeneity (see Kritzinger and van Aarde 1998 for references).Vegetation succession is also known to affect small mammals (Foster and Gaines 1991), though the patterns recorded in coastal dune forests are less obvious than those for birds (see Ferreira and van Aarde 1999 for references).


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Mittwoch, 13 Mai 2020 14:48

STEIGER, P. (1994)

Wälder der Schweiz - Von Lindengrün zu Lärchengold - Vielfalt der Waldbilder und Waldgesellschaften der Schweiz

4. Auflage 2010 | 464 Seiten | A4, Hardcover
ISBN 978-3-7225-0087-4


«Wälder der Schweiz» ist eine umfassende Dokumentation über die erstaunliche Vielfalt des natürlichen Waldkleides der Schweiz. Auf 460 Seiten werden 116 verschiedene Waldgesellschaften mit 788 Farbbildern, Bestandesprofilen und Verbreitungskarten dargestellt. Ein breiter Einführungsteil und ein umfangreicher Anhang mit zahlreichen Registern machen «Wälder der Schweiz» zum unentbehrlichen Nachschlagewerk für alle am Wald und seiner Pflanzenwelt Interessierten.


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Donnerstag, 14 Juni 2018 08:35

Mast (Buchenmast)

Mit "Mast" werden die Früchte der Buchen, Eichen und Kastanien etc. bezeichnet. Da die Produktion der  sehr energiehaltigen Samen der für die Bäume eine erhebliche Anstrengung bedeutet, ist die Samenproduktioon nicht in allen Jahren gleich groß. Der Zeitabstand zwischen zwei "Mastjahren" ist regional unterschiedlich und beträgt sechs bis zehn Jahre. In Jahren mit geringer Mast können sich Fressfeinde wie Rötelmaus und Eichhörnchen nicht so stark vermehren. In den Mastjahren werden wesentlich mehr Samen produziert , als die Fressfeinde verwerten können, uwomit ausreichend Saatgut für eine neue Generation Bäume übrigbleibt.

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Donnerstag, 14 Juni 2018 09:32

NYOKA, B. I. et al. (2011)

The State of the World's Forest Genetic Resources - Country Report Zimbabwe 2002-2011.

82 Seiten.

Ministry of Environment and Natural Resources Management, Republic of Zimbabwe. © Forestry Commission, ISBN 0-7974-5000-4.

Executive Summary:

The Ecosystem Land Classification Approach adopted by the Convention on Biological Diversity (CBD) divides Zimbabwe into five eco-regions: the Kalahari, 46,891 km² (12%); Central, 195,379 km² (50%); Zambezi, 62,521 km² (16%); Save-Limpopo, 78,151 km² (20 %) and the eastern highlands covering 7,815 km² (2%) of the total land area.

Indigenous forests
The natural forest ecosystem is classified into Flora Zambesiaca and Afromontane phyto region. The Flora Zambesiaca comprises five woodlands types: dry Miombo (17,690,074ha), Mopane (12,277,515ha), Combretum-Terminalia (2,374,729ha), Acacia (1,581,070ha) and Zambezi teak (1,404,544ha). The main commercial timber species are Baikiaea plurijuga and Pterocarpus angolensis found in the Zambezi teak woodlands. The Afromontane phyto region covers 781,500ha.

Exotic Forest Plantations
The forest plantations are found in the eastern part of the country where rainfall is high enough to sustain tree growth and productivity. There are also smaller plantations of eucalypts in the central part of the country (Mvuma, Norton and Marondera, Eagle’s nest). The plantation forests (155,000ha) account for 0.4% of the land area. The plantations are all of exotic species of pines, eucalypts and the black wattle (Acacia mearnsii). The exotic plantations provide timber, poles, pulp and paper, tannin and furniture. The success of the plantation industry is largely linked to the genetic improvement programme of exotic timber species that began in 1958. Dozens of exotic tropical and sub-tropical Pinus spp. were introduced and tested for adaptation, growth and timber qualities. Zimbabwe has a very simple but effective advanced generation breeding programme of Pinus patula, P. taeda, P. elliottii and P. kesiya, Eucalyptus grandis, Eucalyptus tererticornis and E. camaldulensis that produce and markets high quality tree seed locally, regionally and internationally. There are over 3,100 Plus trees that were selected in all the exotic species.

Contribution of the forestry sector
The commercial forestry industry based on exotic trees contributes about 4% to the Gross Domestic Product. The commercial plantation based industry employed an average of 14,600 people between the period 2005 and 2010. However there was a general decline in the industry as shown by a significant decline of 29% between 2009 and 2010. The production of paper and paper products declined between 2005 and 2009. In 2002, exports of forestry products were US$20 million and increased to over US$30 million in 2010.

The indigenous hardwood industry based on B. plurijuga and P. angolensis employs an additional 2,000 people and a significant number in the downstream furniture industry. Commercial harvesting of hardwoods has declined over the years from 44,000m3 in 1990, to 22,000 in 1996 and 20,000m3 in 2002 mainly due to raw material shortages as a result of over-harvesting in the past decades. Other than the commercial timber industry, the contribution of the forests to the national economy is grossly under-estimated as reliable statistics are not available for both the environmental services and the informal sector. It is estimated that firewood provides over 80% of the energy used by rural households and 40% of the urban population. Other than fuelwood, forests provide fruits, mushrooms, honey, bush meat, edible caterpillars and insects, vegetables, medicines, poles, bark string and browse for livestock and wildlife. Over 78% of the rural households in Zimbabwe use herbal medicines at least once in a year for both humans and livestock.

Forests protect important watersheds which support large irrigation dams in the country as well as many water courses. Forests also provide habitats for wildlife which is the major basis for the country’s tourism industry, the third highest foreign currency earner after agriculture and mining. There is a need for the country to develop reliable methods to capture all these contributions to better understand the role.

Protection of forests
Cumulatively, over 867,000ha of forest land were burnt by fire in the protected forests between 2004 and 2010. In 2010 alone, over 79,000ha of protected indigenous forests were burnt by fire. In the forest plantations, a cumulative 32,000ha of plantation area was burnt between 2005 and 2010. In one single year (2009), almost 20% of the exotic plantation area was burnt by fires. There is a need for the country to urgently strengthen the capacity of the forest authorities to enable them to control wild fires that evidently, have had a huge impact on both the economy and forest resources.

Changes in forest cover
The latest statistics available (2008) indicate that woodlands have declined from 53.2% to 42.3%; bushland from 12.7% to 10.8%; wooded grasslands from 3.1% to 2.3% and grasslands from 1.8% to 1.2%. The natural moist forest has not changed and remains at 0.03% while the exotic plantations marginally increased from 0.40% to 0.43%. The area under cultivation increased from 27.5% to 41.2%. More than 330,000ha of land are now being lost to agriculture (crops) annually compared to 70,000ha per year prior to this upsurge. Unless this is translated into increased agricultural output from the converted land, it will represent a huge loss nationally.

Invasive woody species
The new environmental law (Environmental Management Act) recognises the threat posed by invasive trees and other woody species. The major invasive species include Lantana camara, Pinus patula, Populus canescens, Acacia mearnsii, Jacaranda mimosifolia and Psidium spp. The priority must now be to quantify the extent of the invasion in all areas by species, develop control strategies, estimate the cost of controlling the invasions, determine the environmental costs, to ensure that progress on control is quantified and monitored.

In situ and Ex situ Conservation of forest genetic resources
Zimbabwe uses multiple strategies to conserve forest genetic resources. In situ conservation in the country’s formally protected areas (protected forests and parks wildlife areas) add up to 49,700 km² while a further 56,135 km² is protected under the CAMPFIRE. There are also sacred trees, forests and landscapes whose protection is mostly cultural. The exact number of sacred forests and woodlands and their extent in Zimbabwe is however not known. The National Herbarium and Botanic Garden in Harare and its outstation in Mazowe (Mazowe Botanical Reserve) have built a comprehensive collection of plants found in Zimbabwe and the southern African region totalling 1,060 plant species, representing 82% of the 1,230 woody species found in Zimbabwe.

The Nationals Parks and Wildlife Management Authority manages ex situ forest genetic resources through two botanic gardens, Ewanrigg near Shamva (area of 286 ha) and Vumba, near Mutare, (area of 242 ha). Exotic industrial tree species are mostly conserved as seed (23,000 accessions) and in arboreta and clone banks. There are more than 3,100 Plus trees being conserved.

Legislation and Policies on Forest Genetic Resources
The management of forest resources in Zimbabwe is still dualised; the Forest Act regulates the use of forest resources on state and private land, and the Communal Lands Forest Produce Act (CLFPA) governs the use of forestry resources in communal areas. The Forest Act mandates the Forestry Commission to manage forest genetic resources in the country and regulate its activities specifically on protected forests (state forests) and forests on private land while the CLFPA gives local communities limited rights to exploit the forest resources in their area for subsistence use only. The Parks and Wildlife Act provides for the protection of six types of areas: national parks, safari areas, sanctuaries, botanical gardens, botanical reserves and ecreational parks, each with a specific objective. The Environmental Management Act provides for the conservation of and access to biological diversity and the regulation of biological and genetic resources. The other pieces of legislation with relevance to the management of forest genetic resources in Zimbabwe include: Traditional Leaders Act, Seeds Act and Plant Pests and Diseases Act. National policies and action plans that relate to the management, conservation and utilisation forest genetic resources in Zimbabwe are the National Environment Policy (NEP), Forest Based Land Reform Policy (FBLRP) and Zimbabwe National Biodiversity Strategy and Action Plan (NBSAP).

Threatened Trees and shrubs
A number of trees and shrubs are listed as endangered or threatened. Most of the endangered or threatened woody species are either endemic or have a very restricted distribution in Zimbabwe. The species include Warbugia salutaris, Swynnertonia cardinea, Combretum umbricola, Combretum coriifolium, Juniperus procera, Bivinia jalbertii, Homalium abdessammadii, Scolopia mundii, Cassia afrofistula, Ficus bubu, Ficus fischeri, Ficus ottoniifolia subsp. ulugurensis, Milicia excelsa, Morus mesozygia, Streblus usambarensis and Turraea eylesii. The challenge now is to reverse the decline in the populations and number of the trees of these species.

Important tree species
There are both indigenous and exotic tree species that are important in Zimbabwe for timber, poles, fodder, gum Arabic, fruit and medicinal. They include exotic timber species (Pinus patula, P. taeda, P. elliottii and P. tecunumanii), exotic species for poles (Eucalyptus grandis, E. tereticornis and E. camaldulensis), furniture (Baikiaea plurijuga, Pterocarpus angolensis and Afzelia quanzensis), indigenous fodder tree species (Faidherbia albida and Acacia erioloba), medicinal (Warbugia salutaris), gum Arabic (Acacia karroo) and indigenous fruit tree species (Uapaca kirkina, Strychnos cocculoides, Adansonia digitata, Sclerocarya birrea and Vangueria infausta). Some of these important species have active breeding programmes while others are in conservation programmes.

Education and Training
There are now several state and quasi-state colleges and universities in Zimbabwe that offer training from Diploma to MSc level in general forestry, forestry and wildlife management, wildlife and rangeland management, natural resource management, agroforestry and tropical resources ecology. Two colleges: Zimbabwe College of Forestry and Mushandike Natural Resources College offer training at Diploma level in forestry and natural resources management respectively; Bindura University offers training up to MSc in forestry; the National University of Science and Technology, Midlands State University, Chinhoyi University of Technology and Africa University offer training at BSc level in natural resources. The Institute for Environmental Studies of the University of Zimbabwe offers an MSc programme on tropical ecology and resources. No university however offers training in specialist areas such as forest genetics and conservation.

The main forestry research projects are on breeding of industrial exotic tree species. There is also limited research on breeding of non-industrial exotic and indigenous tree species. Besides their usual teaching activities, some universities have also complemented the Forestry Commission in conducting research particularly on the management of indigenous forests. There have been collaborative projects involving international research organisations (ICRAF, CIFOR and IPGRI) but these were mostly scaled down during the hyperinflationary period. A number of NGOs (SAFIRE and CTDT) have been carrying out research on value addition (processing of wild fruits) and other non-wood forest products.

Future Needs and Priorities

  • Due to economic challenges in the past decade, some of the planned activities on conservation of forest genetic resources were scaled down. The stabilisation of the economy presents opportunities to revisit some of the planned activities. In future therefore:
  • There will be a need to conduct expeditions to verify the existence or disappearance of some of the tree species that have been reported as extinct or critically endangered.
  • There will be a need to map the important sacred forests and determine their number, location and size as well as their floristic composition.
  • There is a need to conduct comprehensive genetic studies (molecular and quantitative) on the endangered tree species and develop optimum conservation strategies for them.
  • The research and development in forest trees in Zimbabwe has remained basic, relying on what may now be inefficient approaches. There is a need to use modern methods that are fast, efficient and more reliable and perhaps cost effective in the long run.
  • On invasive woody species, the priority must be to quantify the extent of the invasion in all areas; the cost in terms of control and lost environmental services to ensure that progress on control is quantified and monitored.
  • In the short term there will be a need to prioritise ex situ conservation of the trees species listed on the National Red Data List. Efforts must be placed on both the protection of the remaining trees and stands as well as artificially aiding their reproduction.
  • There will be an urgent need for the relevant institutions to initiate the re-introduction into natural habitats of species that now only exist in the home gardens.
  • There is a need to review forest policies and laws to align them with current land ownership as well as global trends on ABS. In view of the concluded land reform, there is a need to review the applicability of the present laws to the new land ownership system.
  • Zimbabwe does not as yet have any programmes and projects exploring Carbon trade. This is an area that can potentially strengthen the conservation of forest genetic resources.
  • Restoration of the membership of the Forestry Commission to major cooperatives and networks (CAMCORE, SAFORGEN, IUFRO, etc) should be a major priority. This is expected to enable Zimbabwe to not only access germplasm but also allow local scientists to engage with their peers in international fora.


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Donnerstag, 14 Juni 2018 14:56

WAGNIÈRE, S. & VOGEL, C. (1992)

Höhlenbäume suchen und sichern.

SVS/SBN-Merkblatt. 20 Seiten. Basel und Zürich.

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Waldrand - Artenreiches Grenzland.

Leitfaden zur ökologischen Aufwertung des Waldrandes. SVS / SBN. Basel. 40 Seiten

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Donnerstag, 14 Juni 2018 16:59

RAJKARAN, A. (2011)

A status assessment of mangrove forests in South Africa and the utilization of mangroves at Mngazana Estuary.

Phil. II Diss. Nelson Mandela Universität, Port Elizabeth.


In South Africa mangrove forests are located in estuaries from Kosi Bay in KwaZulu-Natal (KZN) to Nahoon Estuary in the Eastern Cape. The aims of this study were to determine the present state of mangroves in KwaZulu-Natal, by assessing the current population structure, the changes in cover over time and associated anthropogenic pressures. A second objective of this study was to determine the effect of harvesting on the population structure and sediment characteristics in the Mngazana mangrove forest. To determine if harvesting was sustainable at Mngazana Estuary; the growth and mortality rates and associated growth conditions were measured. Finally by using population modelling sustainable harvesting limits were determined by predicting the change in population structure over time. The study focussed on the KwaZulu-Natal province as a fairly recent study addressed mangrove distribution and status in the Eastern Cape Province. A historical assessment of all mangroves forests in KwaZulu-Natal (KZN) revealed that the potential threats to mangroves in South Africa include; wood harvesting, altered water flow patterns coupled with salinity changes, prolonged closed-mouth conditions and subsequent changes to the intertidal habitat. As a result mangroves were completely lost from eleven estuaries in KZN between 1982 and 1999 and a further two estuaries by 2006. Mangroves only occurred in those estuaries where the mouth was open for more than 56 percent of the time with the exception of St Lucia, where the mouth has been closed for longer but the mangrove communities have persisted because the roots of the trees were not submerged. All mangrove forests in KZN were regenerating in terms of population structure as they had reverse J-shaped population curves as well as high adult: seedling ratios. Kosi Bay and Mhlathuze Estuary were two of the larger forests that showed signs of harvesting (presence of tree or branch stumps), but the greatest threat to smaller estuaries seems to be altered water flow patterns due to freshwater abstraction in the catchments and the change of land use from natural vegetation to sugar-cane plantations. These threats affect the hydrology of estuaries and the sediment characteristics (particle size, redox, pH, salinity, temperature) of the mangrove forests. The environmental conditions under which the mangrove forests currently exist were determined for five species. Lumnitzera racemosa and Ceriops tagal exhibited a narrow range of conditions as these species are only found at Kosi Bay, while Avicennia marina, Bruguiera gymnorrhiza and Rhizophora mucronata were found to exist under a wider range of conditions. The growth rate and response to environmental conditions of the three dominant species were important to determine as these species are impacted by harvesting. Mangrove growth rates were measured at Mngazana Estuary in the Eastern Cape, the third largest mangrove forest in South Africa. Areas of this estuary where mangroves harvesting has occurred, show significant differences in sediment characteristics as well as changes in population structure in harvested compared to non harvested sites. The growth rate (in terms of height) of Avicennia marina individuals increased from seedlings (0.31 cm month-1) to adults (1.2 cm month-1), while the growth of Bruguiera gymnorrhiza stabilised from a height of 150 cm at 0.65 cm month-1. The growth of Rhizophora mucronata peaked at 0.72 cm month-1 (height 151-250 cm) and then decreased to 0.4 cm month-1 for taller individuals. Increases in diameter at breast height (DBH) ranged between 0.7 and 2.3 mm month-1 for all species. Some environmental variables were found to be important drivers of growth and mortality of individuals less then 150 cm. A decrease in sediment pH significantly increased the mortality of Avicennia marina seedlings (0-50 cm) (r = - 0.71, p<0.05) and significantly decreased the growth of Rhizophora mucronata and Bruguiera gymnorrhiza seedlings (r = -0.8, r = 0.52 – p < 0.05 respectively). At Mngazana Estuary, mortality of this species showed a positive correlation with sediment moisture content indicating that this species prefers drier conditions. The density of Rhizophora mucronata was significantly correlated to porewater temperature in Northern KZN as was the growth of adult (>300 cm) Rhizophora trees at Mngazana Estuary. Mortality of Avicennia marina individuals (51-150 cm) was related to tree density indicating intraspecific competition and self thinning. Selective harvesting of particular size classes of Rhizophora mucronata was recorded when comparing length of harvested poles (~301 cm) and the size class distribution of individuals. Taking into account the differences in growth rate for each size class for this species it will take approximately 13 years to attain a height of 390 cm which is the height at which trees are selected for harvesting at this estuary. This is 2.6 times slower than those individuals growing in Kenya. The feasibility of harvesting is dependent on the growth rate of younger size classes to replace harvested trees as well as the rate of natural recruitment feeding into the population. Different harvesting intensity scenarios tested within a matrix model framework showed that limits should be set at 5 percent trees ha-1 year-1 to maintain seedling density at > 5 000 ha-1 for R. mucronata. However harvesting of Bruguiera gymnorrhiza should be stopped due to the low density of this species at Mngazana Estuary. Harvesting of the tallest trees of Avicennia marina can be maintained at levels less than 10 percent ha-1 year-1. Effective management of mangrove forests in South African is important to maintain the current state, function and diversity of these ecosystems. Management recommendations should begin with determining the freshwater requirements of the estuaries to maintain the mouth dynamics and biotic communities and deter the harvesting of (whole) adult trees particularly those species that do not coppice. Further management is needed to ensure that forests are cleared of pollutants (plastic and industrial), and any further developments near the mangroves should be minimized.

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Donnerstag, 14 Juni 2018 15:59

MÜLLER, J. (2004)

Vögel als Inspektionsbeamte in Eichenwäldern.

LWF Wissen 46: 22-28.


  • Vögel  zeigen  Naturnähe auf  drei Skalenebenen, nämlich Einzelstruktur, Bestand und Landschaft, an.  Wegen  ihrer  hohen  Mobilität können sie diese Indikatorfunktion sehr zeitnah erfüllen.
  • Naturnahe Wälder müssen von Baumarten der potentiellen natürlichen Vegetation dominiert werden.
  • Daneben ist ein intensiver Wechsel von Waldentwicklungsphasen, wie er für temperate Laubwälder  typisch ist, wichtig. Nur so können die vollständigen Artengemeinschaften von Naturwäldern integriert werden.
  • Starke und anbrüchige Altbäume spielen eine Schlüsselrolle und sollten relativ gleichmäßig erhalten  werden.  Dabei  können  großkronige Wirtschaftswaldeichen die eher kleinkronigen Urwaldeichen in ihrer ökologischen Funktion ersetzen.
  • Das Ziel Furnierholz dient sowohl bei kurzschaftigen und großkronigen Mittelwaldbäumen als auch bei alten und langsamgewachsenen Hochwaldeichen den beiden Vogelarten Mittelspecht und Halsbandschnäpper, vorausgesetzt  ein  ausreichender Alteichenvorrat ist auf der Fläche präsent.
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Donnerstag, 14 Juni 2018 09:45

STEIGER, P. (1994)

Wälder der Schweiz - Von Lindengrün zu Lärchengold.

Vielfalt der Waldbilder und Waldgesellschaften der Schweiz.

Ott Verlag, Thun. 4. Auflage 2010 | 464 Seiten | A4, Hardcover. ISBN 978-3-7225-0087-4


«Wälder der Schweiz» ist eine umfassende Dokumentation über die erstaunliche Vielfalt des natürlichen Waldkleides der Schweiz. Auf 460 Seiten werden 116 verschiedene Waldgesellschaften mit 788 Farbbildern, Bestandesprofilen und Verbreitungskarten dargestellt. Ein breiter Einführungsteil und ein umfangreicher Anhang mit zahlreichen Registern machen «Wälder der Schweiz» zum unentbehrlichen Nachschlagewerk für alle am Wald und seiner Pflanzenwelt Interessierten.

Die anhaltende Nachfrage hat zu einer vierten, überarbeiteten Auflage geführt. Der zunehmend wichtiger gewordenen Biodiversität und den Waldreservaten ist neu ein eigenes Kapitel gewidmet.

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Donnerstag, 14 Juni 2018 23:41

KREMER, Bruno P. (1990)

Naturspaziergang Wald: Beobachten - Erleben - Verstehen.

Kosmos Naturführer. Franckh'sche Verlagsbuchhandlung, Stuttgart. ISBN 3-440-06024-1.


Das gute an diesem Buch ist, es handelt sich hierbei nicht um ein Pflanzen- und Tierbestimmungsbuch. Vielmehr werden, und das ist gerade für den Laien wichtig, allgemeine Zusammenhänge des Waldlebens deutlich gemacht, die Aufgaben aller Waldbewohner und die Folgen von menschlichen Eingriffen erläutert. Schön - und überlegt auch selbstverständlich - ist die Gliederung des Buches in die vier Jahreszeiten; wenn zwar einige Kapitel meines Erachtens nicht unbedingt einer speziellen Jahreszeit zuzuordnen sind, so schadet das kaum. Interessant war der Abschnitt zur jahrgenauen Datierung eines Balkens beispielsweise aus einem Fachwerkhaus. Leider wurden einige Begriffe nicht exakt definiert und mittels Fotos erläutert, wenngleich bereits viele Bilder enthalten sind.

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