: IS DURBAN’S FLAGSHIP REFORESTATION PROJECT MEETING STATED TARGETS?
Kathryn Terblanche, Kevin Kirkman, Hylton Adie, Debra Roberts, Errol Douwes
• South Africa’s major port city • Population: 3.5 million • Area: 2 300 km2 (888 mi2) • 30 – 40% unemployment • 37% 20+ completed high school
• Contains four of South Africa's eight biomes • Seven vegetation types • Over 2000 indigenous plant taxa • Durban is part of a global biodiversity hotspot • Substantial development deficits - created by:
• shortage of human and financial resources, • increasing levels of informality, • poor governance, • environmental degradation, • biodiversity loss, • poverty, • growing inequality.
• This ultimately means that environmental projects need to address poverty alleviation and help to reduce inequality to be sustainable in the long term.
• The Environmental Planning and Climate Protection Department (EPCPD) - EThekwini Municipality.
• Restore natural forest and woodland in the buffer zone of the Buffelsdraai Regional Landfill site.
• Offset a portion of the carbon emissions related to the hosting of the ‘carbon neutral’ 2010 FIFA World Cup™.
• Climate change adaptation role – to improve city resilience.
The location of Buffelsdraai Community Reforestation Project within the eThekwini Municipal Area
• 100 ha footprint but is surrounded by a 800 ha buffer zone.
• Initially covered by over 500 ha of sugarcane.
• Wildlands Conservation Trust’s ‘Indigenous Trees for Life’ concept.
• Through tree planting, these projects are able to sequester carbon as well as alleviate poverty.
• Previously sugar cane • Depleted seed bank • Uplift local communities • Quick
• Forests supply many ecosystem services – buffer.
• Trees are easier to trade.
• Grasslands are a fire risk to the landfill.
To determine whether active restoration implemented at Buffelsdraai will satisfy stated objectives of the restoration program.
1. To examine: • species richness; • species diversity; • stem density; • species composition; and • functional diversity (partially explored).
2. To compare active restoration sites with a reference ecosystem.
• It is critical for management of the project.
• This study will: • Determine biological composition of sites being restored. • Aid adaptive management on site and allow the department to fine-tune/adjust their management of the site. • Provide baseline data for monitoring. Is the project meeting its stated goals? • Three active restoration sites.
• Project planting blocks -2009, 2010 and 2011.
• 20 200m2 (2153 ft2) circular plots at each site.
• Chosen randomly prior to field work.
• Steel peg with a 7.98 m (26 ft.) length of 7.98m tape attached to it. • Plant identification. • Active restoration – planted specimens only.
• Are we going in the right direction?
• Intact forest/woodland patches at Kenneth Stainbank Nature Reserve.
• Same methodology – (20x 200 m2 (2153 ft2) random plots).
• Stems dbh >10 cm (4 in)
1400
1200
1000 Implications: 800 • Sprawling trees 600 • Grass dominated • Fire 400 • Competition Stemsper hectare
200
0 Site 1 (2009) Site 2 (2010) Site 3 (2011) Mean planting density (stems per ha). Error bars represent 95% CI.
All sites below recommended reforestation planting density 40
35
30
25 Site 1
20 Site 2
15 Site 3 10 Site 4 (KS)
species richnessRarefied 5
0 0 50 100 150 200 250 300 350 400 450 No. of Individuals
Tree species encountered per number of individuals through Mao-Tau sample- based rarefaction in EstimateS (Colwell)
35
30
25
20
15
10
5 number of Effective species
0 Site 1 Site 2 Site 3 Site 4 (KS)
Species diversity (Shannon exponential) (Chao and Shen, 2010). Error bars represent 95% CI. 1
0.5 KS B1 0 B2 -1.5 -1 -0.5 0 0.5 1 1.5 B3
-0.5
-1
Differences in communities illustrated by an MDS plot using Bray Curtis similarity (PRIMER 6). Error bars indicate 95% CI. • Acacia caffra • Acacia karroo • Erythrina lysistemon • Dalbergia obovata NITROGEN FIXERS / SPRAWLING STRUCTURES / PERSIST IN FIRE
• Croton sylvaticus • Englerophytum natalense • Searsia chirindensis • Xylotheca kraussiana • Drypetes arguta FOREST ONLY Fast growing, sprawling species dominating the reforestation sites, but forest species missing
• Treepreneur choices (Easy to grow? Fast growing?)
• Seed collection (what's in the vicinity?)
• Survival
35 30 25
20 15 10 5
of species 0 Site 1 Site 2 Site 3 Site 4 (KS) Effective number Sites • More sun tolerant trees planted now, could act as nurse trees for the forest trees, which can be added at a later stage. • Not yet complete • Traits • Wood density (g/cm3) • Seed mass (g) • SLA (cm3/g) • Dispersal mode (CATEGORICAL) • Resprouter (CATEGORICAL)
• Analyses (SPSS) • Log transform • MANOVA and post hoc tukey - continuous data • Chi square - categorical data • Increase density to reduce the risk of fire and speed up growth. • Increase diversity. • Start teaching people to grow forest species. • Source a good quality forest nearby where seeds can be collected. • Be prescriptive about what trees to be grown. • Perhaps offer incentives for the more rare / forest species.
University of KwaZulu-Natal College of Agriculture, Engineering and Science Grassland Science Masters by Dissertation
Kathryn Terblanche (213573257) [email protected]
Thanks to:
Prof Kevin Kirkman, Dr Hylton Adie, Dr Debra Roberts & Mr Errol Douwes
Funding: