L2- Improved Logging

Scale of Logged Tropical Forests:

• 20% of tropical forests were logged in 2000-2005

• 400m hectares of tropical forest are in permanent timber estate (maintained for the purpose of producing timber)

• There are regional differences e.g. Africa, Asia and Central America have high logged forests but South America has the enormous Amazon so has less logged forest

  

Selective Logging in the Tropics:

• only large marketable trees are cut, felling is precise

• smaller trees, vines and other vegetation getting damage when cutting down big trees

Effect of logging on biodiversity:

1. Species composition

   • ordination plot- the points closer together have a similar composition of species

     

     → significant difference in all birds composition in each type of forest, similar pattern in all, greater shift in once-logged to twice-logged

2. IUCN red-listed bird species

   • e.g. Rufous-collared Kingfisher:

     • there is a significant reduction in abundance when logged once but not when logged twice

     • abundance does not decline to 0

     

3. % of species from unlogged forests persisting

   • logged forests cause a 25% loss in primary forest species but most persist

     

+ → substantial amount of biodiversity persists, including red-listed species

- → changes species compositions, some species go extinct, harmful, relogging can magnify the harm

How to manage logging:

• focuses on the first cut of trees→ logging the first time in primary forests

• Market Incentives→ FSC (Forest Stewardship Council), REDD+ (reducing emissions, payments from global north to global south to protect forests)

• Regulation→ Brazilian Amazon

How to manage logging to reduce biodiversity losses:

1. Reduced Impact Logging

   • Preharvest Inventories- Comprehensive Harvest Plan (identify, measure, geo-locate all trees that are harvestable, protected and mature seeds)

   • Preharvest Preparations- Plan roads (straight, narrow, on route to target trees), Limit log dumps (have a central one), Cut vines (at ground level so will die)

   • Harvest- use trained crews for directional felling (know where it will fall) and extraction, use big tracked vehicles (no soil compaction, balances weight)

   • Positives:

     • reduces damage to forest structure, release of carbon, increases the viability of harvest over time

     • is a prerequisite for timber certification in the FSC and gives access to lucrative western markets

   • Does it work in practice?

     • comparing conventional logging to RIL in Borneo:

       

       → get the same amount of timber but get less residual damage in RIL→ YES

     • there are far fewer damaged stems in RIL, even at high levels of tree extraction:

       

     • less area is disturbed in RIL→ less skid trails→ better recovery:

       

     • RIL is better for all saplings:

       

     • Meta-analysis (lots of data from lots of studies) of species abundance changes in primary, CL and RIL forests:

       

       → RIL have less negative impacts than CL for birds and mammals

2. Lower Intensity Logging

   • has been shown in agriculture to reduce biodiversity losses

   • Does it work in practice?

     • Meta analysis of species richness in primary and logged forests:

       

       • birds have a minor positive effect (new niches due to opening up habitat)

       • invertebrates have a minor negative effect

       • mammals and amphibians suffer a 50% loss at 38/63m3ha

     • Problem with study→ does not include logging in SE Asia- other studies show logging of high intensity in Borneo show more than 50% biodiversity remaining

       → overall, lower intensity harvesting would save a lot of biodiversity but get less timber yields and spreads logging out

3. Land-sharing vs Land-sparing

   • has been used in agriculture before

   • get the same amount of timber yield and net profit:

     

   • Which is better in practice?

     • generated 1000 hypothetical communities using 4 low yield transects vs 3 high yield and 1 primary transect

     • calculated overall species richness (community level) and abundances of each species (species level):

       

       → there are more of all species and primary forest species in land-sparing forests

     • totaled up the winners vs losers:

       

       → there are more winner species in all species and primary forest species

     → land-sparing is the best way to manage logging for biodiversity

   • Need to develop policy drivers for land-sparing:

     • how big should the spare patch be? reducing edge effects, ranges

     • what happens after logging stops? illegal logging, hunting

     • is this best for carbon retention? REDD+ to bridge financial gap

Conversion of Logged Forests:

• Happens the most in over-logged forests

• Effect of converting logged forests:

  

  • Selective logging has little negative effect on species richness

  • Converting logged forests to another landscape dramatically increases this negative effect

• How to prevent logged forest conversions:

  1. Conservation Purchases

     • the RSPB/Birdlife pay the Indonesian government to protect the Harapan forest

     • Is it better to protect primary or degraded forests?

       • Fisher et al. had logging records for 300,000ha of forest→ saw step-wise records for each time logged

       • Calculated net value of timber when cut once, twice and for the final time

       • timber value vs primary forest species:

       

       → timber value reduces massively when logged once and then twice

       → marginal reduction in primary forest species when logged once, but not twice

     • forest value from timber vs biodiversity:

       

       → lost 60% of value of timber after once logged but only 20% of value of biodiversity

       → still have 80% biodiversity value at twice-logged

     → protecting twice logged forest has lower costs and retains most of the biodiversity (1ha unlogged= 5ha twice-logged)

     → need to understand the optimal balance between purchasing unlogged (connectivity) vs logged forests

  2. Carbon Enhancements & REDD+

     • capturing carbon and then selling under REDD+, through increasing the rate of carbon removal:

       • cut off lianas and shrubs→ increases tree growth, more CO2 captured by tree

       • plant more trees

     • Ways this has been successful:

       • timber value increases slowly in twice-logged forests but much faster in restored forests (45 years to get back the same amount of carbon/value as primary):

       

       • logged and thinned forests have a lot more carbon sequestration than others:

       

       • getting rid of lianas increases the harvest of brazil nuts:

       

     • Does this help biodiversity?

       • Actively restored forests accelerate carbon recovery compared to naturally restored forests:

         

       • there is minimal impact (differences) on species compositions of birds (communities) in primary, actively restored and naturally restored forests:

         

     • There are species that are affected by logging:

       • 12 species declined, 7/12 are IUCN red-listed

       • there is a loss in mean species richness in logged forests but there is no further loss of species when actively restoring:

         

       • there are small negative effects of restoring forests on phylogenetic diversity:

         

       • there are also small negative effects of restoring forests on functional diversity→ less roles:

         

     • Positives→ higher timber values, minimal effect on species composition and loss, no conversion of logged forests

     • Negatives→ affects phylogenetic and functional diversity, expensive to plant trees

Extra Information:

• Birdlife International- StateOfWorld’sBirds Report:

  • 1/8 bird species are threatened with extinction

• Brazilian Amazon study- sparing comes at a financial cost