A Scientific Basis for Protecting Woodlands Through Control Over Activities Affecting Protected Trees and Woodlands Under the National Forests Act of 1998
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A SCIENTIFIC BASIS FOR PROTECTING WOODLANDS THROUGH CONTROL OVER ACTIVITIES AFFECTING PROTECTED TREES AND WOODLANDS UNDER THE NATIONAL FORESTS ACT OF 1998 Van der Merwe, I.J. and Stehle, T.C. Department of Agriculture, Forestry and Fisheries, South Africa Corresponding author: [email protected] [email protected] PROTECTED TREE SPECIES Figure 1: Selection Criteria for Protected Tree Species, with scoring system. Figure 3: Protected tree scoring system rules application A list of 47 tree species have been declared CRITERIA SCORES ASSOCIATED WITH CRITERIA as protected under the National Forests Act Red List Status/ • Critically endangered to vulnerable = 2 points CRITERIA Adequate Partially Seriously Biodiversity • Near threatened to lower risk = 1 point RATINGS Legislation Inadequate Inadequate of 1998. These include many woodland tree Legislation Legislation Keystone Species • Species important to ecosystem functioning and species such as Combretum imberbe and species dependent on tree = 1 point No Scores (Low 0 / 0 0 / 1 0 / 2 Acacia erioloba. No one may cut a protected Sustainability of Use • Significant commercial or livelihood use = 1 point Threat or Species not Importance) selected for Cultural/Spiritual Value • High landscape value or importance to tree without a license. Tree species are protection cultural/spiritual values = 1 point Low Scores (Low 1 / 0 1 / 1 1 / 2 to Moderate Threat selected on the basis of one or more of 4 Adequacy of Legislation • Adequate existing legislation = 0 points or Importance) criteria, namely Rarity; Keystone Species (Score given separately) • Partially inadequate legislation = 1 point value; Use Value and Cultural or Spiritual • Seriously inadequate legislation = 2 points Moderate to High 2 / 0 2 / 1 2 / 2 Scores (Moderate Species Figure 2: Example of scoring system applied to Acacia erioloba Value. Decision-making for the listing and to High Threat or selected licensing processes of protected tree (camel thorn). Importance) for Acacia Red List/ Keystone Sustaina- Cultural/ Adequacy TOTAL Very High Scores 3 / 0 3 /1 3 / 2 protection species must be legally defensible, and legal (High Threat or erioloba Biodiver- Species bility of Spiritual of Importance) precedent has shown that these must have a (Camel sity Use Value Legislation thorn) scientific basis, especially if contested in 0 1 1 1 2 3/2 court. LICENSING GUIDELINES FOR HARVESTING OF PROTECTED PROTECTED WOODLANDS – KATHU FOREST TREES Certain woodlands may be declared as protected under the National Forests Act of Basic guidelines have been developed for the licensing of 1998. In 2007 the Kathu Forest was declared as the first protected woodland under applications to harvest protected trees in woodlands. Market the Act. This uniquely dense Camel thorn woodland in the Northern Cape was studies indicate large braaiwood use in metropolitan areas (more divided into 3 use zones based on the density and height of trees, namely a core than 500 tons per month in Gauteng alone) with more than 80% from protection zone, an ecotourist zone and low density nature-oriented development savanna woodlands. Fauna and flora surveys in the Kgalagadi zone. Research indicates a direct correlation between tree size and density and region indicate high plant and animal biodiversity associated with biodiversity in veld types dominated by Acacia erioloba. Tree height and density is mature Acacia erioloba trees, with some species also associated therefore a surrogate of biodiversity, used for protected woodland planning. with dead trees. Harvesting of only dead trees are allowed, except for live tree harvest done according to plans based on studies of Insectivore Frugivore tree densities, size classes and other criteria which may determine Granivore Carnivore Insect/seed Scavenger SPECIES SIGHTINGS sustainable harvesting levels. n = 42 n = 525 60 12.5% 45.8% 48.6% 1990 Figure 4: The monitoring of SAPLING 32.4% 25.0% n = 105 1997 8.3% 1.9% population size and size classes of n = 24 10.5% 50 8.3% 6.7% 65.1% savanna tree species, or numbers 28.1% 6.3% 40 of trees of size classes harvested LARGE TREE 12.5% 25.0% 9.4% 9.4% 4.7% 7.5% over time, are vital to determine n = 32 18.8% 3.1% n = 318 30 10.1% 26.9% regeneration rates, responses to 3.8% 41.2% DEAD TREE 15.4% 34.3% 20 harvesting, and the sustainability of 26.9% 11.5% 1.0% n = 26 15.4% 3.9% 13.7% n = 102 harvesting practices and levels. 5.9% Relative (%) frequency 10 Such studies inform the guidelines Figure 6: Correlation between and conditions set for the licensing WOODLAN TREE COVER NO-GO AREA 0 tree size of Acacia erioloba and 0-5 5-10 10-15 15-20 20-25 25-30 of the commercial use or cutting of D CLASS 1 +70% Only hiking trails & Stem diameter (cm) bird numbers and diversity TREE SIZE limited vehicle tracks protected tree species. +10m height (Dean, WRJ; 2002) +2.5m trunk circ Figure 5: Market surveys of braaiwood indicated that in Gauteng more than 80% of WOODLAN TREE COVER LOW IMPACT AREA Map 1 & Figure 7: Kathu Forest (a D CLASS 2 +40% Only low-impact eco- the wood originates from savanna tree TREE SIZE tourist development species (mostly Colophospermum mopane, protected Acacia erioloba woodland) with +6m height (trails, tracks, picnic Combretum apiculatum and Dichrostachys land use zones based on woodland +1m trunk circ sites etc.) density and tree size, which are also cinerea. Of these 2% are from protected tree WOODLAN TREE COVER BUFFER AREA species such as Combretum imberbe. In correlated to landscape value and D CLASS 3 +30% Limited low-density biodiversity TREE SIZE residential development Cape Town more than 30% of the braaiwood 3– 6m height with off-set agreement originates from Acacia erioloba. +0.5m trunk circ SAVANNA VEGITATION CONS FORMAL TRANS- THREAT BIOREGION TYPES TARGET PROTECTI FORMED STATUS DEVELOPMENT CONTROL IN ON WOODLANDS CENTRAL MARIKANA 19% 1% 48% EN BUSHVELD THORNVELD When protected trees are affected by development, the threat status and SPRINGBOK FLAKTE 19% 1% 49% EN shortfall in protected area target on the THORNVELD savanna woodland or Albany thicket veld types are taken into consideration VHAVENDA MIOMBO 100% 0% 10% EN to determine the license conditions or biodiversity off-set. The protected area targets are based on floristic Figure 8: Example of flagged woodland types indicating biodiversity data (species area-curve), threat status and shortfalls in conservation targets. If and are therefore at the basis of affected by development and no alternatives are Figure 9: Example of new land use (transmission lines possible, a biodiversity off-set will be required as development control decisions. indicated in red) super- imposed on savanna veld types, to condition of the license issued to cut protected trees. determine whether sensitive woodlands are affected. .