Upload
world-agroforestry-centre
View
160
Download
0
Embed Size (px)
DESCRIPTION
Trees, landscapes, restoration, Tree Diversity Day 2014, CBD, biodiversity, forests, plantations, seeds, diversity, seedlings, policy, indigenous people
Citation preview
Assessing the success of forest and landscape restoration efforts – What do genetic diversity indicators tell us? Riina Jalonen and Judy Loo
2
Enormous potential of restoration to improve resilience – unmet?
• Aichi Target 15: quantitative but also qualitative
• Political commitments provide great potential for build in adaptedness in new forests
• But: little information about the quality of restored forests and actual success in restoring diverse and resilient systems
3
Survival of planted trees on the restoration site
• Origin of seed must match (current and future) site conditions to ensure adaptedness
Good growth, reproduction and resilience over tree generations
• Seed source forests must be large and genetically diverse enough to avoid inbreeding and to contain genetic material for natural selection
• Good seed collection practices must be observed to capture the genetic diversity of the seed sources
Genetic diversity is the foundation for:
Photo: Lee Soong Leong
4
Juglans nigra (Black walnut)
• Broad distribution in the US
• A provenance trial in 7 locations, 15-25 provenances planted at each location
• Survival after 22 years was much higher for local than for the other provenances (71% vs. 0% at some sites)
Bresnan et al. 1994
Example: importance of adaptedness for survival
Photo: Rebecca Sherman
5
Acacia mangium
• Introduced to Sabah from Australia in 1967 in two small stands (34 and ca. 300 trees)
• All trees had the same mother tree
• Used to establish more than 15 000 ha of plantations
• A nursery trial showed reduction in average height by 44% from the first to the third generation (Sim 1984)
Example: Effects of poor seed collection practices accumulate over generations
Generation Height (cm)
First 32.5
Second 20.7
Third 18.1
Assessing success of restoration efforts with genetic diversity Indicators
7
Trends in population condition
Verifiable indicator Verifier
7. Genetic condition of selected populations (population geneticstructure where appropriate)
7. Genetic parameters7.1. Effective population size7.2. Allelic richness7.3. Outcrossing/inbreeding rate7.4. Spatial genetic structure7.5. Hybridization/introgression
Graudal et al. 2014
Verifiable indicator Verifier
9. Profit from breeding vs. loss from ill-adapted plantations
9.1. Seed source performance (growth and survival)9.2. Realized genetic gain and profit
Trends in (plantation) performance of selected species
8
Trends in sustainable use of genetic resources
Verifiable indicator Verifier
16. Number of tree species for which regulation of use of forestreproductive material exist
16. Number of tree species for which regulation of use of forest reproductive material exist
17. Number and type of improved seed sources traded/exchanged (status of genetic improvement)
17. Number and type of improved seed sources traded/exchanged
18. Guidelines/regulations for matching seed source and planting site
18.1. Certification scheme in place18.2. Use of adapted seed sources
19. Guidelines/regulations for composition and harvest of seedsources (number of mother trees)
19. Use of diverse seed sources
Graudal et al. 2014
9
Approach – Trends in population condition and performance
• Literature review of genetic studies conducted in restored forests – How many studies conducted to assess success in restoring
genetic diversity of tree species in forest restoration?– How many of these studies indicate adequate genetic
considerations in restoration practice?
• CAB Direct (1973-2014)– Tree OR shrub OR forest– Restored OR rehabilitated OR reforested OR afforested OR
revegetated OR reintroduced– Genetic OR gene flow OR provenance
10
Approach – Trends in Sustainable use
• Review of the Country Reports for the State of the World’s Forest Genetic Resources report (2014)
• 8 countries in South, Southeast and East Asia– China, India, Indonesia, Myanmar
Nepal, Philippines, Sri Lanka Thailand
– Most have set national restoration targets and/or established national restoration programmes
• Reports published in 2011-2013
Results
12
Trends in population condition and performance of selected species in restored forests
• 23 studies (2003-2014)
• 22 tree species
• 14 families
• 12 countries
0
1
2
3
4
Nu
mb
er
of
stu
die
s
13
7.1. Effective population size- Seed was collected from few , often related, trees in 6 of 7 studies- Broadhurst et al. 2006, Burgarella et al. 2007, Cruz Neto et al. 2014, Kettle et al. 2008, Krishnan et al. 2013,
Navascues & Emerson 2007, Ritchie & Krauss 2012
7.2. Allelic richness- Significantly lower in restored than natural populations in
8 of 13 studies- Broadhurst 2011, 2013 ; Burgarella et al. 2007, Huang et al. 2013, Li et al. 2005, Liu et al. 2008, Navascues &
Emerson 2007, Pakkad et al. 2008, Oliveira et al. 2006, Ritchie & Krauss 2012, Ruan et al. 2013, Salas-Leiva et al. 2009, Zhang et al. 2006
- Geneflow from surrounding natural populations increased allelic richness in planted populations in 4 of 5 studies
- Broadhurst 2013, Cruz Neto et al. 2014, Navascues & Emerson 2007, Pakkad et al. 2008, Ritchie & Krauss 2012
7. Genetic condition of populations
14
7.5 Spatial genetic structure
• Planted trees were genetically distant from nearby natural populations in 8 studies of 13
• Broadhurst 2011, 2013 ; Burgarella et al. 2007, Cespedes et al. 2003, Huang et al. 2013, Krishnan et al. 2013, Li et al. 2005, Liu et al. 2008, Navascues & Emerson 2007, Pakkad et al. 2008, Sanchez et al. 2008, Sinclair et al. 2006, Ritchie & Krauss 2012, Zhang et al. 2006
9.1. Seed source performance (growth and survival)
• Lower germination, survival and/or height growth in restored vs. natural populations in 3 of 4 studies
• Broadhurst et al. 2006, Li et al. 2012, Sanchez et al. 2008, Ritchie & Krauss 2012
15
17. Number and type of improved seed sources traded/exchanged• Seed from identified, selected or
tested sources available for 270 species
• Seed supply is insufficient to meet the demand for quantity and/or quality, according to 7 of 8 countries
• Lack of seed from identified sources for native, endangered, and agroforestry species
• Awareness of seed quality is low
Trends in sustainable use of genetic resources – Eight Asian countries
Photo: Soumitra Dhali
16
18.2. Use of adapted seed sources– Seed zones based on environmental
variation in 7 countries– Respective seed sources for main
species identified– Detailed seed zones for key species
based on progeny trials in 3 countries
– Problems: • In 43% of cases, only one
identified or selected seed source per species in a country
• Seed production areas insufficient to meet the demand in each zones
• EnforcementPhoto: KMA Bandara
17
• Problems:- Lack of quality seed for native sp. - Narrow genetic base of trees,
especially on farm- Inadequate requirements for seed
source areas?
19. Use of diverse seed sources
• Mandatory guidelines for tree seed collection for restoration in two countries
- Reliance on clonal material for restoration
- Uncontrolled import of low quality seed - disincentive
Conclusions
19
The results suggest that it is common in forest restoration to– Pay insufficient attention to
geographical origin of seed– Use seed sources are too small to
produce quality seed– Fail to capture the genetic
diversity of the source populations during seed collection
ConclusionsConsequences:– Poor germination– Poor height growth– Poor survival
20
• Asian countries have made good progress in enhancing seed supply from identified and tested sources
• But– These sources are still insufficient to meet the demand,
especially for native, endangered and on-farm species– Even govt led restoration programmes may use unidentified seed or rely
on clones– Relying on one seed source per species not likely to ensure diversity and
resilience– Seed source classification has focused on level of selection and
geographical origin – but are the source populations also large and genetically viable?
Resilience? Carbon sequestration? Effective use of resources?
Conclusions
Recommendations
22
“it is extremely difficult to get people collect seed from more than just
one tree”- Restoration researcher and practitioner with 20+ years of experience
23
• Policy makers: Create demand for good quality seed of native tree species through political commitment, regulatory frameworks and resource allocation
• Experts: Adjust existing seed collection guidelines to restoration context and changing climate
• Education and extension : Provide training and support to restoration practitioners about seed collection and propagation techniques for native tree species
• Everyone: Advocate for a more holistic view in evaluating restoration success : quantity AND quality
Recommendations
Preparing seed for direct seeding. Photo: Luciana Akemi Deluci
24
Bozzano et al. 2014
25
• New Working Group to review current tree seed programmes and identify approaches for strengthening them
• www.apforgen.org
• Similar networks in other regions – EUFORGEN, LAFORGEN, SAFORGEN
Asia Pacific Forest Genetic Resources Programme (APFORGEN)