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Innovation Fund Project Commercial Products IMPACT OF UNCONTROLLED BARK HARVESTING ON THE RESOURCE BASE: information from a resource inventory in Umzimkulu forests Coert J Geldenhuys Dept of Forest Science, University of Stellenbosch c/o Forestwood cc, Pretoria, South Africa [email protected] Outline • General background • The Bark Problem • Study design & results – Resource condition & management • Lessons learned Background • Observations in many areas of natural forest & woodland • Uncontrolled, unsustainable resource harvesting practices & rates • In spite of National Forests Act 1998 & Provincial Ordinances • Bark use for traditional medicine impact on species, ecosystems & future business • NEED: Integrated action plan for sustainable business development through adaptive management research • We can look at impact from two sides, using • Resource inventory in forest (Umzimkulu) • Market information in urban areas (Johannesburg) CP Wild study on Bark for Traditional Medicine • 4 species selected from natural forest: – Ocotea bullata, Curtisia dentata, Rapanea melanophloeos & Prunus africana • 4 main study components – Resource management studies – Laboratory studies on genetics & chemistry – Development of alternative resources – Trade chains & business development • Focus of this presentation: Resource management – Reconnaissance of harvesting impacts in resource areas – Inventory design, implementation & results Observations during Reconnaissance survey Flourishing Market Degrading Declining protected species: forest Ocotea bullata & Prunus africana NORTH Resource Ngw angw ane Dlokolwana Riverside inventory: d2 d3 d4 d1 Hoha to develop basis Eny aniswen h3 h2 h1 Ntsikeni for improved kwa1 Kwabeni Mhlengwa 3029 BC 3029 BD resource m1 m2 Umzimkulu management Sneezewood b3 b1 b sn2 sn1 Malowe Bantam g2 g1 g3 mp3 Gunjini Mhlabas m2 m1 'Mzimkulu mp1 mp2 Mpur m3 m4 z4 z3 z2 z1 Ben Cairnie bc2 Mbigi bc1 Nzimankulu 13 forests Tweef ontein File Sihleza Kok's Hill in Umzimkulu District L1 s2 sihleza B s4 s3 s Rietv lei 37 transects Langgewacht s5 3029 DA 3029 DB 389 plots of 0,04 ha s1 Ngele 6 weeks Ngele Kokstad Weza Forest Station Harding Information recorded • Species & DBH • For bark-stripped species – Transect slope – Bole length – Crown health condition – Size of bark wound – % bark removed round stem Forests sampled and Forest types a. TWINSPAN classification b. DCA Ordination (CANOCO 0.5 400 300 E 0.4 i 200 g e 100 n 0.3 v 0 a l -100 0.2 u Axis 2 (Eigenvalue = 0.403) e -200 -200 -100 0 100 200 0.1 Axis 1 (Eigenvalue = 0.576) 1.10 1.23 1.22 1.21 2.30 2.20 2.10 Type 110 Type 122 Type 210 Type 230 Type 121 Type 123 Type 220 Forest Associations 95 species recorded, 36 species harvested 7281 stems recorded, 6.1% harvested Ochna holstii 4 25.0 Allophylus dregeanus 148 8.1 Olinia emarginata 7 14.3 Apodytes dimidiata 22 9.1 Podocarpus falcatus 81 3.7 Bersama swinnyi 11 18.2 Ptaeroxylon obliquum 387 1.8 Buddleja saligna 30 3.3 Rhus chirindensis 43 16.3 Burchellia bubalina 6 16.7 ia mundii 64 7.8 Calodendrum capense 187 2.7 Scolop m gerrardii 29 3.4 Canthium mundianum 30 3.3 Syzygiu cladus ellipticus 240 5.8 Cassipourea gummiflua 7 14.3 Tricho Cassine papilosa 8 25.0 Xymalos monospora 1646 0.2 um davyi 215 1.9 Celtis africana 267 4.5 Zanthoxyl Cryptocarya myrtifolia 33 15.2 Casearia gladiiformis 6 50.0 Cryptocarya woodii 118 16.1 Chionanthus peglerae 11 36.4 Dovyalis lucida 6 16.7 Ekebergia capensis 11 18.2 Curtisia dentata 50 60.0 Euclea natalensis 12 8.3 Ocotea bullata 359 57.4 Heywoodia lucens 55 3.6 Pittosporum viridiflorum 2 100.0 Kiggelaria africana 273 2.6 Prunus africana 10 70.0 Maytenus peduncularis 15 6.7 Pterocelastrus rostratus 29 86.2 Rapanea melanophloeos 124 38.7 Ocotea bullata Rapanea melanophloeos Population status of key 100 Ocotea bullata 100 50 80 ems 80 40 bark-stripped species st 60 60 30 40 20 mber 40 • Affected species have Nu 20 20 10 Number stems Number stems 0 0 0 bell-shaped DBH curves 9.9 19.9 29.9 39.9 49.9 59.9 69.9 79.9 89.9 99.9 9.9 19.9 29.9 39.9 49.9 59.9 69.9 79.9 89.9 99.9 Stem diameter, cm Stem diameter, cm Stem diameter, cm All stems All stems All stems Harvested stems • Few species severely Harvested stems Harvested stems Curtisia dentata Prunus africana impacted 25 3.5 3 20 2.5 15 2 10 1.5 1 5 Number stems • Only smaller trees not Number stems 0.5 0 0 harvested 9.9 19.9 29.9 39.9 49.9 59.9 69.9 79.9 89.9 99.9 9.9 19.9 29.9 39.9 49.9 59.9 69.9 79.9 89.9 99.9 Stem diameter, cm Stem diameter, cm All stems All stems Harvested stems Harvested stems • O. bullata has no single Pterocelastrus rostratus Kiggelaria africana stems <15 cm DBH, only 20 60 50 15 coppice stems on stumps 40 10 30 20 5 Number stems Number stems 10 0 0 • P. africana has no young 9.9 19.9 29.9 39.9 49.9 59.9 69.9 79.9 89.9 99.9 9.9 19.9 29.9 39.9 49.9 59.9 69.9 79.9 89.9 99.9 Stem diameter, cm Stem diameter, cm stems – only few seedlings All stems All stems underneath parent trees Harvested stems Harvested stems SPECIES DO NOT REGENERATE IN UNDISTURBED FOREST! Intensity of bark harvesting • Important tree Curtisia dentata 30 species intensely Cryptocarya woodii 19 Ocotea bullata 205 harvested Pterocelastrus rostratus 25 Pittosporum viridiflorum 2 • Bark removal Xymalos monospora 3 Scolopia mundii 5 – often totally Rapanea melanophloeos 38 around stem Ptaeroxylon obliquum 7 Zanthoxylum davyi 4 – Generally to Prunus africana 7 Rhus chirindensis 7 2-3 m height 0 102030405060708090100 – often to 10 m % bark harvested from main bole – occasionally Mean of all harvested trees total bole Maximum harvested per tree Value inside graph: • Sometimes trees number of trees harvested are cut Internal & external flows of Natural capital People Environment Natural Environment Capital = Biophysical system Flows of capital = Value to Forest Environment •Environment Animals •Society Physical •Individuals Plants Internal flows Natural external flows Human external flows Costs & benefits ed Potential value of Forest Capital Bark value US$/ha Forest area = 1114 ha 5000 4000 4 species (O bullata, P africana, R. 3000 lue US/ha a 2000 melanophloes, C myrtifolia) v 1000 Bark 0 9 192939495969798990+ Stem diameter cm (upper limit) Timber volume = 57 957 m³ Bark value wasted Bark value used Timber value = US$15.2 million Timber value US$/ha Actually used = Zero 1200 1000 800 lue US$/ha 600 a Bark volume = 8.91 million kg 400 mber v i 200 T Bark value = US$30.5 million 0 9 192939495969798990+ Actually used = US$7.6 million (25%) Stem diameter cm (upper limit) Timber value wasted Dead trees = LOST VALUE (ecologically & economically) Harvest method affects tree survival •Decline in crown condition: –Not related to amount harvested as % of total –Decline serious if debarking is >80% of circumference (ring-barking) Implement sustainable harvesting practices Experiment implemented in George-Tsitsikamma forests to assess harvest & recovery rates Method O. bullata C. dentata R.melanophloeos Controlled harvesting: 1 m long vertical strips of 5 cm width Tree response observed during inventory Basis for improved resource management Coppice develops, but browsed; if tree dies, coppice also dies Tree cutting stimulates coppice regrowth Coppice grows 3 – 4,5 m in 18 months & offers: Tree survival, Rotational harvesting, Use of leaves Fell dying trees to stimulate coppice growth (+ protection), to use all bark (additional 60-80%) & timber, in rotation Results from Re-survey in 2004 • P. africana: – 9 trees harvested, 1 died with no coppice regrowth. • O. bullata: – 126 trees recorded – Few cut – 80 harvested standing (63.5%) • 66 dead (82.5%) – 34 (51%) showed some sign of sprouting. – 50% of trees of protected species lost from system. Discussion: Is the impact so devastating? • Much devastation occurred • NO CONTROL! • Loss of trees of protected species • Lost value of bark & timber • Forest not a museum piece – A DYNAMIC SYSTEM!! Discussion: What to do? • Understand species requirements & responses • Target species require more light (disturbance) for seedling establishment: • Disturbance necessary? • CITES regulations? • Species differ in bark recovery & coppicing ability • Adapt management system to species characteristics • Cut dying trees to ensure survival via Coppice management • Harvest more bark (on average 70% of Ocotea) • Utilize timber • Focus of FRP-DFID study • Natural evergreen forests (South Africa & Malawi) • Miombo woodlands (Malawi & Zambia) THANKS FOR YOUR ATTENTION.
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