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Kruger National Park

Scientific Services

Exclosures

Maps of whereabouts of all exclosures and enclosures

 Location of the Letaba, Nkhulu and Makhohlolo exclosures  Photograph taken from the back corner of the exclosure forward  Close up of the fence that is used fro the axclosure
 Photograph taken from the riverside of the exclosure backwards  Photograph taken from the back of the exclosure towards the front

Description of each past and present and what type of research occurs there

The three exclosures mentioned here are the Letaba on the Letaba River, Nkuhlu on the Sabie River opposite Nkuhlu picnic site and Makhohlola in the south-eastern corner of the KNP just north of Crocodile Bridge. Table 1 provides a summarized description of the exclosures.

Table 1. Brief description of the scientific exclosures in the KNP

Exclosure Meaning of name Year of construction Size Substrate type Vegetation type

Letaba

Sotho for “sand river”

2002

129 ha

Granite (sandy soils)

Letaba River Rugged Veld - mainly mopane/combretum woodland with distinctive riparian zone

Nkuhlu

Tsonga for “natal mahogany”

2002

139 ha

Granite (sandy soils)

Thickets of the Sabie and Crocodile Rivers - dense woody vegetation referred to as Acacia nigrescens/Combretum apiculatum association

Makhohlola

Tsonga for “he who coughs all the time”

Early 1970’s

4 ha (of which 2 ha unfenced)

Basalt (clayey soils)

Sclerocarya birrea/Acacia nigrescens Savanna – open tree savanna


Purpose

The main purpose of these exclosures is to determine the effect of different combinations of fire, elephants and other herbivores on the vegetation. The exclosures will be maintained and managed as such for the next 20-25 years during which close monitoring of changes will be done. The set-up also provides ideal opportunities for other research, such as soil – plant relationships, soil nutrient and population dynamic studies.

Scientific Issues

During the initial stages of the exclosures, baseline vegetation surveys were conducted to serve as benchmarks against which subsequent changes will be measured. These surveys will be repeated every five years, thereby building a time-series dataset.

A detailed soil survey, including a classification and descriptions of soil profiles, has been completed in 2003. Fine-scale orthomaps with contour intervals of 0.5 m were also produced for both Letaba and Nkuhlu exclosures, based on low-level aerial photography.

On-going data collection on soil water parameters is being performed since the beginning of the exclosures and will provide important information on soil water movement locally and along the toposequence.

Fixed-point and aerial photography have also been conducted to form part of the longer term monitoring programmes.

There are a number of projects that have been registered in both the exclosures and enclosures. Please see the attached file for more details.

Management Issues

The exclosures are regularly patrolled and inspected; breakages and faulty electrical systems are reported immediately and usually soon afterwards attended to by a qualified maintenance team. Serious damage to the sacrificial exclosures have been inflicted by higher flows of the rivers.