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Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity
Sustainable management
of logged tropical forests
in the Caribbean to ensure
long-term productivity
For more information, please contact:
Forestry Division – Natural Resources and Sustainable Production
E-mail: FO-Publications@fao.org
Web address: www.fao.org/forestry/en
Food and Agriculture Organization of the United Nations
Rome, Italy
ISBN 978-92-5-134660-0 ISSN 2664-1062
FORESTRY
ISSN 2664-1062
WORKING
9 789251 346600 PAPER
FAO
27
CB5484EN/1/09.21
Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity Michael Köhl & Sebastian Gräfe University of Hamburg Germany Claus Eckelmann & Kenichi Shono FAO Quacy Bremner Forest Training Center Incorporated Guyana Michael Oatham University of the West Indies at St. Augustin Trinidad Ramon Pacheco Programme for Belize Belize and Maureen Playfair Centre for Agricultural Research in Suriname (CELOS) Suriname FOOD AND AGRICULTURE ORGANIZATION OF THE UNITED NATIONS Rome, 2021
Required citation: Gräfe, S., Köhl, M., Eckelmann, C.M., Bremner, Q., Oatham, M., Pacheco, R., Playfair, M. and Shono, K. 2021. Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity. Forestry Working Paper No. 27. Rome, FAO. https://doi.org/10.4060/ cb5484en The designations employed and the presentation of material in this information product do not imply the expression of any opinion whatsoever on the part of the Food and Agriculture Organization of the United Nations (FAO) concerning the legal or development status of any country, territory, city or area or of its authorities, or concerning the delimitation of its frontiers or boundaries. The mention of specific companies or products of manufacturers, whether or not these have been patented, does not imply that these have been endorsed or recommended by FAO in preference to others of a similar nature that are not mentioned. The views expressed in this information product are those of the author(s) and do not necessarily reflect the views or policies of FAO. ISSN 2664-1062 [Print] ISSN 2664-1070 [Online] ISBN 978-92-5-134660-0 © FAO, 2021 Some rights reserved. This work is made available under the Creative Commons Attribution- NonCommercial-ShareAlike 3.0 IGO licence (CC BY-NC-SA 3.0 IGO; https://creativecommons.org/ licenses/by-nc-sa/3.0/igo/legalcode). Under the terms of this licence, this work may be copied, redistributed and adapted for non- commercial purposes, provided that the work is appropriately cited. In any use of this work, there should be no suggestion that FAO endorses any specific organization, products or services. The use of the FAO logo is not permitted. If the work is adapted, then it must be licensed under the same or equivalent Creative Commons licence. If a translation of this work is created, it must include the following disclaimer along with the required citation: “This translation was not created by the Food and Agriculture Organization of the United Nations (FAO). FAO is not responsible for the content or accuracy of this translation. The original [Language] edition shall be the authoritative edition.” Disputes arising under the licence that cannot be settled amicably will be resolved by mediation and arbitration as described in Article 8 of the licence except as otherwise provided herein. The applicable mediation rules will be the mediation rules of the World Intellectual Property Organization http://www.wipo.int/amc/en/mediation/rules and any arbitration will be conducted in accordance with the Arbitration Rules of the United Nations Commission on International Trade Law (UNCITRAL). Third-party materials. Users wishing to reuse material from this work that is attributed to a third party, such as tables, figures or images, are responsible for determining whether permission is needed for that reuse and for obtaining permission from the copyright holder. The risk of claims resulting from infringement of any third-party-owned component in the work rests solely with the user. Sales, rights and licensing. FAO information products are available on the FAO website (www. fao.org/publications) and can be purchased through publications-sales@fao.org. Requests for commercial use should be submitted via: www.fao.org/contact-us/licence-request. Queries regarding rights and licensing should be submitted to: copyright@fao.org. Cover photo: Forest worker marking a harvest tree in Suriname. ©Sebastian Gräfe
CONTENTS
Foreword v
Acknowledgements vi
Acronyms and abbreviations vii
Key messages viii
Part 1: SUSTAINABLE MANAGEMENT OF TROPICAL PRODUCTION FORESTS 1
1. Relevance and state of tropical forests 1
2. Timber harvesting and sustainable forest management in the tropics 3
3. Practice of silviculture 5
4. Challenges related to SFM in the tropics 7
4.1 Understanding SFM 7
4.2 Post-harvest recovery and rotation cycles 8
4.3 Impact of selective logging and fixed harvest regulations 8
4.4 Effects of silvicultural treatments 9
5. Sustainable forest management and REDD+ 10
Part 2: THE CARIBBEAN CASE STUDIES 13
1. Approach and methodology 14
2. Categorization of commercial timber stock 18
3. Sustainability of logged forest management 20
3.1 Felling cycle and recovery of timber volume 20
3.2 Current condition of forest stands under different tenure types 21
3.3 Impacts of past management and logging codes on sustainability 24
3.4 Selection and protection of future crop trees 26
4. Economic viability of future crop tree release in logged forests 27
5. Impact of future crop tree release on forest carbon stocks 30
Part 3: GUIDELINES FOR LOGGED FOREST MANAGEMENT IN THE CARIBBEAN 33
1. Background 33
2. Applicability and use of this guideline 34
3. Future crop tree concept 34
4. Harvesting and silvicultural operation process 34
5. Pre-harvest planning 36
5.1 Pre-harvest inventory 36
5.2 Mapping 39
5.3 Preselection of future crop trees and harvest trees 40
5.4 Field selection and marking of future crop trees 41
5.5 Skid trail planning 43
6. Field measures to protect and enhance future crop trees 43
6.1 Directional felling 43
6.2 Skidding 44
6.3 Silvicultural treatments 44
References 46
Further reading 54
iii
FOREWORD
Lowland tropical forests around the Caribbean have been subjected to logging for
centuries. The intensity of timber harvesting has varied from country to country and
within countries between different management regimes. These selectively logged
forests constitute an important resource that can continue to provide quality timber
and ecosystem services if managed sustainably. In most cases, these forests are
accessible, and still contain many valuable timber species despite modified species
composition and structure.
To facilitate sustainable management of logged forests in the Caribbean, forest
authorities of Belize, Guyana, Suriname, and Trinidad and Tobago, jointly with the
Food and Agriculture Organization of the United Nations (FAO) and the University
of Hamburg, World Forestry, as scientific partner, implemented the regional project
“Ensuring Long-Term Productivity of Lowland Tropical Forests in the Caribbean”.
The project was financed by the German Federal Ministry of Food and Agriculture
and implemented from September 2015 to December 2019.
The main objective of the project was to support sustainable management of
logged forests to maintain productivity and prevent further degradation. For this
purpose, extensive field studies were conducted in the project countries, which
resulted in silvicultural recommendations presented in this publication. In addition,
the project examined the economic feasibility and applicability of the silvicultural
method of future crop tree release as an activity in support of REDD+.
Section 1 of this paper presents the overall context, including the global status
of tropical forests, common harvesting practices, the practice of silviculture, and
challenges to sustainable forest management in the tropics. Section 2 presents the
findings of the field studies conducted under the project and discusses implications
for forest management. Finally, the guidelines presented in Section 3 describe
the planning process and measures to maintain and enhance the future crop of
commercial trees in the forest. Although the project was implemented in the
Caribbean, the results and guidelines are also relevant and can be replicated in other
tropical regions. We hope that these guidelines will support forest managers and
extensionists in improving the sustainability of logged forest management in the
tropics.
v
ACKNOWLEDGEMENTS
This publication presents the key results of the project “Ensuring Long-Term
Productivity of Lowland Tropical Forests in the Caribbean,” funded by the German
Federal Ministry of Food and Agriculture. The project was implemented jointly by
FAO and the following government agencies and partners in the project countries in
collaboration with the University of Hamburg, Center for Earth System Research and
Sustainability and Institute for Wood Sciences – World Forestry as scientific partner.
BELIZE
Forest Department, Ministry of Forestry, Fisheries and Sustainable Development,
Belmopan, Belize
Programme for Belize, Belize City, Belize
GUYANA
Guyana Forestry Commission, Georgetown, Guyana
Forestry Training Centre Incorporated (FTCI), Georgetown, Guyana
SURINAME
Foundation for Forest Management and Production Control (SBB), Paramaribo,
Suriname
Centre for Agricultural Research in Suriname (CELOS), Paramaribo, Suriname
TRINIDAD AND TOBAGO
Forestry Division, Ministry of Agriculture, Land and Fisheries, Port of Spain, Trinidad
and Tobago
The University of the West Indies (UWI), St. Augustine, Trinidad and Tobago
Feedback from the following reviewers provided valuable inputs to this publication:
Jonas Cedergren, Prem Neupane, Adriana Patricia Yepes Quintero, Maricarmen Ruiz-
Jaén, Marieke Sandker, Lucio Santos, Tiina Vähänen, Maria Ruiz Villar, and Sheila
Wertz-Kanounnikoff.
Copyediting and proofreading were provided by James Varah, and design was
undertaken by Flora Dicarlo.
vi
ACRONYMS AND ABBREVIATIONS
AGB above-ground biomass
ANR assisted natural regeneration
CBD Convention on Biological Diversity
DBH diameter at breast height
FAO Food and Agricultural Organization of the United Nations
FCT future crop tree
FSC Forest Stewardship Council
GHG greenhouse gas
ITTO International Tropical Timber Organization
MAC maximum allowable cut
MHD minimum harvesting diameter
PEFC Programme for the Endorsement of Forest Certification
RIL reduced impact logging
REDD+ reducing emissions from deforestation and forest degradation and the
role of conservation, sustainable management of forests and
enhancement of forest carbon stocks in developing countries
SFM sustainable forest management
UNCED United Nations Conference on Environment and Development
UNFCCC United Nations Framework Convention on Climate Change
UNFF United Nations Forum on Forests
vii
KEY MESSAGES
1. In addition to the critical roles that tropical forests play in biodiversity
conservation, the global carbon cycle, livelihood support and provision of other
ecosystem services, the world’s tropical forests are also of great importance from
an economic viewpoint as production of wood remains the dominant primary
objective of forest management in many countries.
2. About 2/3 of tropical forests have been affected by human activities, mainly
through selective harvesting. Sustaining productivity of these logged forests can
maintain forest management as a financially viable land use option, reducing the
likelihood of conversion and maintaining the flow of diverse forest benefits.
3. The application of general sustainable forest management protocols for tropical
production forests that set limits on harvesting (e.g. minimum felling diameter,
annual allowable cut, fixed rotation period, etc.) does not necessarily ensure
sustained productivity if the composition and management of the residual stand
are not considered.
4. The ratio of number of harvested trees to the remaining future crop trees can
provide a simple indicator of sustainability of harvest. If the current harvest
exceeds the number of future crop trees, the harvest is not sustainable. As a rule
of thumb, at least one, preferably two future crop trees per harvested tree should
be retained for future use.
5. To ensure sustainability, it is important to select future crop trees from the same
group of commercial species currently being harvested. Otherwise, the stand
composition will shift from high-value timber species to those of less value,
resulting in high grading of the forest.
6. From the current diameter of future crop trees and species-specific growth rates,
it is possible to estimate the time when a sufficient number of trees will become
harvestable. The commonly applied felling cycles for natural forest harvesting in
the tropics are generally not sufficient to allow for the recovery of growing stock
of commercial timber species.
7. Future crop tree release aims to expand the growing space of these trees and
thereby accelerate their growth by removing competing trees nearby. This
silvicultural operation incurs costs, which may not be recoverable through the
increased growth of released future crop trees within the cutting cycle or the
logging permit period. However, the economic feasibility depends on many
factors that cannot be generalized or predicted with certainty. These factors
include future timber price, growth rate of commercial timber species before and
after release, choice of discount rate, costs associated with the release operation
and future harvesting, etc.
viii8. Release of future crop trees enhances the productivity and value of the forest
by directing biomass increment to high-value trees. However, the removal of
competitors will result in temporary decline of forest carbon stock. This illustrates
the potential trade-offs among the different forest management objectives as
improved productivity may not lead to conservation or enhancement of forest
carbon stocks within the desired timeframe.
9. Protection of future crop trees can be a simple and practical approach to
preventing high grading and degradation of the forest growing stock. Even if
it is not economically feasible to release future crop trees, it is still important to
identify and mark these trees to ensure protection of trees that represent the
future economic value of the forest. The importance of reduced impact logging
to reduce unnecessary damage to the future crop trees and for sustainable forest
management in general is stressed.
ixCanopy of an intact tropical forest in the Caribbean. ©FAO/Giancarlo Pucci
Part 1: SUSTAINABLE MANAGEMENT
OF TROPICAL PRODUCTION FORESTS
1. RELEVANCE AND STATE the global export value of industrial
OF TROPICAL FORESTS roundwood in 2019 (FAO, 2020b).
With an area of 4.06 billion ha, forests Forests contain large amounts of
cover about 31 percent of the global carbon and act both as a source and sink
land area. Tropical forests account of carbon (Butarbutar et al., 2019; FAO,
for 45 percent of the total forest area 2020a). They thus play a key role in the
(FAO, 2020a). Forests are home to the global carbon cycle and climate change.
greatest part of the world’s terrestrial The carbon stocks of tropical forests
biodiversity, and tropical moist forests alone are estimated to be 306–324
are known to be particularly diverse, billion tonnes, of which 49–53 percent
containing about 60 percent of all are bound in tropical primary forests
plant species (FAO and UNEP, 2020). (Mackey et al., 2020). Primary forests
In addition to their diverse ecosystem cover 32 percent of tropical forest area
services, forests provide the basis of (Morales-Hidalgo et al., 2015). Each year,
life for a large number of people. It is tropical forests sequester between 0.47
estimated that 300 to 350 million forest- and 1.3 billion tonnes of carbon, which
proximate people depend on forests corresponds to 8–13 percent of global
for their subsistence and income, and annual anthropogenic CO2 emissions
2.4 billion people rely on wood-based (Mackey et al., 2020). On the other hand,
energy for cooking worldwide (Chao, deforestation in the tropics is responsible
2012; FAO, 2014). for 10–15 percent of anthropogenic
At the local level, communities carbon emissions (Houghton, 2013;
benefit from access to forest products Pearson et al., 2014; Pearson et al., 2017;
such as wood, medicines and fuelwood. Munang et al., 2011)
At the regional level, forests provide Although the rate of deforestation
important ecosystem services such as has decreased over the past three
water regulation, soil stability, flood decades, deforestation and forest
mitigation and improved air quality. degradation continue at an alarming
At the global level, forests make an rate (FAO, 2020a). Since 1990, an
important contribution to economic estimated 420 million ha of forest have
development, biodiversity and climate disappeared through conversion to other
regulation. Timber and processed land uses, with more than 90 percent
forest products contribute more than of the deforestation occurring in the
USD 450 billion to the global economy tropics. Between 1990 and 2010, over
each year, and the annual value of 15 million ha were deforested annually,
internationally traded forest products which slowed to 11.8 million ha per year
reached USD 248 billion in 2019. Tropical in 2010–2015, and further decreased to
hardwood accounted for 24 percent of 10.2 million ha per year in 2015–2020
1Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity
©Kenichi Shono/FAO
Deforested tropical landscape.
(FAO, 2020a). Africa had the highest disproportionately high percentage of
net loss of forest cover, with a loss tropical forests.
of 3.94 million ha per year between The primary driver of global forest
2010 and 2020, while South America loss is commercial agriculture, which
experienced a decline in forest cover of accounts for 70–80 percent of forest
2.6 million ha per year during this period conversion in Africa, around 70 percent
(FAO, 2020a). in tropical and subtropical Asia, and
Despite international attention and over 90 percent in Latin America
measures against deforestation and (Sandker et al., 2017). Commercial
forest degradation, primary forests are logging is the main cause of forest
declining rapidly due to ongoing land degradation in Latin America and
use interventions (Mackey et al., 2015). Southeast Asia, while firewood and
Primary forests account for about one- charcoal production are the main causes
third of the total tropical forest area, of degradation in Africa. These direct
while the rest are forests that have drivers of deforestation, which are
been impacted by human activities to human activities at the local level, are
various degrees. Forest degradation is shaped by indirect drivers including
notoriously difficult to measure and global population and economic growth
monitor because it is difficult to detect and the associated increase in demand
subtle and temporary changes due to for primary raw materials, agricultural
low-intensity forest use through remote products, wood products and minerals
sensing data. In an analysis conducted (Kissinger et al., 2012; Boucher et al.,
by FAO, 185 million ha of forest was 2011; Hosonuma et al., 2012; Geist and
degraded (using partial canopy cover Lambin, 2001).
loss as a proxy for forest degradation) Several international initiatives
between 2000 and 2012, of which and programmes have been launched
156 million ha was in the tropics (FAO, to combat deforestation and forest
2015). This illustrates the wide extent of degradation. Within the framework
forest degradation, which is affecting a of the United Nations Conference
2Part 1: SUSTAINABLE MANAGEMENT OF TROPICAL PRODUCTION FORESTS
on Environment and Development management of forests and the
(UNCED), 179 countries signed Agenda conservation and enhancement of forest
21 and declared their intention to carbon stocks in developing countries
combat deforestation. Under the 2030 (REDD+). The New York Declaration
Agenda for Sustainable Development, on Forests, endorsed by over 200
target 15.2 aims to “promote the governments, multinational companies,
implementation of sustainable groups representing indigenous
management of all types of forests, halt communities, and non-governmental
deforestation, restore degraded forests organizations since 2014, aims to cut
and substantially increase afforestation natural forest loss in half by 2020 and
and reforestation globally” by 2020. strives to end it by 2030. As well, driven
Forest certification systems such as the by increased social and environmental
Forest Stewardship Council (FSC) and awareness of consumers, an increasing
the Programme for the Endorsement number of private companies are
of Forest Certification (PEFC) promote voluntarily committing to eliminating
sustainable forest management (SFM) deforestation from their supply chains.
practices at the local level in order
to prevent forest degradation. The
Convention on Biological Diversity (CBD) 2. TIMBER HARVESTING
adopted the strategic plan for biological AND SUSTAINABLE FOREST
diversity 2011–2020, which includes MANAGEMENT IN THE TROPICS
measures to reduce forest degradation. Despite the increased recognition of the
The United Nations Framework range of products and services provided
Convention on Climate Change (UNFCCC) by forests and the movement towards
developed a framework to guide multi-purpose forest management,
activities in the forest sector that reduces wood production remains the dominant
emissions from deforestation and forest forest management objective globally
degradation, as well as the sustainable and in the tropics. More than 20 percent
©Kenichi Shono/FAO
Primary tropical forest supporting high levels of biodiversity.
3Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity
of humid tropical forests globally have et al., 2011; Keller et al., 2007) with
been allocated to selective timber typical harvesting intensities ranging
harvesting, and forests that have been from two to three trees per hectare
selectively logged dominate secondary (about 8 m3 ) up to 120 m3/hectare or
forests, which comprise two-thirds of the more in dipterocarp forests of Southeast
tropical forest area (Asner et al., 2009). Asia (Armstrong and Inglis, 2000;
Globally, tropical forests have the Appanah and Weinland, 1990).
highest growing stock per unit area Selective logging is performed either
and encompass over half of the world’s as conventional logging or as reduced
standing timber, including some highly impact logging (RIL). Conventional
valued species (FAO, 2020a; Thomas (unmanaged) logging usually makes
and Baltzer, 2002). As only a few little or no use of planning measures
species (or groups of species) have such as pre-harvest inventory or skid
commercial value, tropical production trail planning. Due to the lack of
forests are usually managed through planning, conventional logging leads to
selective logging to extract economically considerable damage to the remaining
attractive trees for timber production stand (Boltz et al., 2003; Rivero et al.,
(Asner et al., 2005; Putz et al., 2012; 2008). Marketable trees are identified
Blanc et al., 2009; Blaser and ITTO, 2011). and felled during harvesting in the forest
The removal rate and intensity are often and later searched for and extracted
controlled by a felling cycle, a diameter by skidders. Harvesting contractors are
limit and an annual production quota usually paid by piece rate, which leads
(or annual allowable cut) (Fredericksen, to quick work with little care for the
1998). Annual logging takes place in one remaining stand. The skidding crews
or more compartments, which are then often lack the information needed
left to recover until the next harvest. to locate the felled trees quickly and
Typical felling cycles in the tropics are precisely. This leads to a highly inefficient
between 15 and 40 years (Hawthorne skidding process, commonly resulting
©Kenichi Shono/FAO
Harvesting operation in an FSC-certified forest concession.
4Part 1: SUSTAINABLE MANAGEMENT OF TROPICAL PRODUCTION FORESTS
in unnecessary skidding damage to the 3. PRACTICE OF SILVICULTURE
remaining stand (Holmes et al., 2002). Silviculture is defined as the theory and
On the other hand, RIL involves practice of controlling the establishment,
intensively planned and carefully composition, constitution and growth
controlled implementation of timber of forests (Ford-Robertson, 1971) to
harvesting operations to minimize meet the diverse needs and values of
environmental impacts on the forest landowners and society. It used to be
stand and soils. RIL techniques were generally assumed that tropical forests
tested in the 1990s and are now naturally and perpetually renewed
standard best practice in tropical themselves after harvesting to sustain
production forest management (van productivity. However, it became
der Hout and van Leersum, 1998; Putz apparent that most commercial timber
et al., 2008; Holmes, 2020). RIL includes species did not regenerate adequately
a number of measures, such as pre- on their own after harvesting, even
harvest inventories, skid trail planning, if conducted at low intensity. In
cutting of lianas on harvest trees, order to sustain production, carefully
protection of sensitive areas and buffer implemented harvesting operations
zones, use of directional felling, closure with appropriate limits need to be
and rehabilitation of log landings and combined with silvicultural treatments to
logging roads, post-harvest assessments, enhance the abundance and growth of
etc. (Dykstra, 2001, 2002; Sist, 2000). commercial timber species.
Currently defined SFM protocols The main objective of silviculture
for production forests mandated by applied in natural production forests is
governments comprise static restrictions to enhance the growth and abundance
or limits on harvesting, including of commercial timber species to
prohibition on felling certain trees (e.g., improve the value of the forest stand.
seed trees and species of conservation Research in tropical silviculture in recent
value), minimum felling diameter, decades has oscillated between two
maximum harvest intensity per unit concepts: artificial regeneration (e.g.
area, and minimum distance between enrichment planting of seedlings of
harvested trees. Little attention is being commercial timber species in canopy
paid to the residual stand and the future gaps); and natural regeneration by
crop trees that remain in the forest. creating conditions conducive to the
The assumption is that there is enough establishment and growth of natural
natural regeneration of commercial trees regeneration of targeted species, for
in the forest to replace the harvested example through thinning (Bertault et
trees within the mandated felling cycle, al., 1995; Putz, 2004).
which often does not hold true. In enrichment planting, forest stands
Considering the vast expanse of are enriched with valuable tree species,
tropical forests allocated to selective which are planted after harvesting.
logging worldwide, sustainable However, planting of tree seedlings
management of logged forests to under closed canopy or in single tree
maintain productivity and prevent further canopy openings without constant
degradation is critical. If sustainably maintenance and continued opening of
managed, these logged forests can the canopy has rarely been successful.
continue to generate financial benefits Planted seedlings require long-term
and incentives for local communities and care to ensure establishment and
forest managers to maintain forest land continued growth (Schwartz et al., 2013;
use, along with many intangible benefits Schwartz et al., 2017; Navarro-Cerrillo
that forests provide. et al., 2011). Enrichment has frequently
5Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity
Figure 1. Liberation of future crop trees (marked in red) by felling competitors
failed to achieve its objective where tree (FCT) release, which can be
the requirements for careful planning considered a form of thinning, refers
and the considerable amount of to the elimination of competitors
maintenance work have not been met of selected smaller sized individuals
(Bertault et al., 1995; dos Santos and of commercially valuable species
Ferreira, 2020; Neves et al., 2019). (Figure 1). One rationale underlying
The current paper is dedicated to FCT release is that dominant and co-
improved management of production dominant trees account for the largest
forests through natural regeneration share of total biomass growth in a
and stand improvement, with the forest stand (Smith, 1997; Dawkins,
aim of promoting the growth of 1955; Wadsworth and Zweede,
existing trees with the potential to 2006; Wadsworth, 1997). Therefore,
produce high-value timber by reducing forest productivity can be improved
competition. The practice is generally significantly by helping smaller
termed thinning, which is a common individuals of commercial tree species
tool of forest management all over attain (co-)dominant positions in
the world. When applied in forest the canopy. It has been shown that
restoration, the approach is termed individual tree measures, such as the
assisted natural regeneration (ANR), selective removal of climbers and lianas,
which aims to accelerate the growth can lead to a substantial increase in the
of natural regeneration of preferred growth of targeted trees (Graaf et al.,
species by reducing competition from 1999; Villegas et al., 2009; Peña-Claros
grasses and other weedy vegetation et al., 2008; Wadsworth and Zweede,
(Shono et al., 2020). Future crop 2006; Mills et al., 2019).
6Part 1: SUSTAINABLE MANAGEMENT OF TROPICAL PRODUCTION FORESTS
4. CHALLENGES RELATED the physical and social environment”.
TO SFM IN THE TROPICS According to the World Commission on
Forests and Sustainable Development,
4.1 Understanding SFM SFM must be “a flexible concept that
Over the past few decades, the concept accepts changes in the mix of goods
of sustainability has increasingly been and services produced or maintained
mainstreamed into tropical forest over long periods of time and according
management. SFM is an approach to to changing values signalled by various
bringing environmental, socio-cultural stakeholders” and should be “seen
and economic management goals into as a process that can be continuously
harmony with the forest principles adapted according to changing
adopted at the UNCED in 1992. values, resources, institutions and
The United Nations Forum on Forests technologies” (Salim and Ullstein, 2000;
(UNFF) developed the non-legally Sist et al., 2014). SFM aims not only to
binding instrument on all types of ensure the flow of goods and services,
forests, which was adopted by the UN but also to keep forest processes intact,
General Assembly in 2007 and specifies including the conservation of the range
seven thematic elements of SFM as of functional species that provide these
follows: goods and services (Thompson et al.,
1. extent of forest resources 2014). SFM considers forests in terms of
2. biological diversity both time and space. SFM represents a
3. forest health and vitality balance between the conservation and
4. protective functions of forests production of forest goods and services
5. productive functions of forests for humans and must operate within
6. socio-economic functions the capacity of the forest to restore and
7. legal policy and institutional maintain its functions (Sist et al., 2014).
framework. Although there are variations in the
These seven thematic elements definition and interpretation of SFM,
illustrate the complexity of SFM, which there is a consensus that the concept
is one reason why there is not a single of SFM encompasses sustaining and
universally agreed definition of SFM. maintaining the full range of products
One of the most widely accepted and services provided by forests for
definitions of SFM adopted by the
UN General Assembly (Resolution A/
RES/62/98) defines SFM as a “dynamic
and evolving concept [that] aims to
maintain and enhance the economic,
social and environmental values of
all types of forests, for the benefit
of present and future generations.”
According to the International Tropical
Timber Organization (ITTO, 2005), SFM
is “the process of managing forest to
achieve one or more clearly specified
©Sebastian Gräfe
objectives of management with regard
to the production of a continuous flow
of desired forest products and services
without undue reduction of its inherent
values and future productivity and
without undue undesirable effects on Logs being transported in Belize.
7Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity
present and future generations through conditions within a reasonable period)
a flexible and adaptable approach. (Sist et al., 2014).
Despite the recognition of the However, a meta-analysis on the
importance of SFM, production forests recovery of tropical forests after logging
in the tropics are seldom managed indicates that only 54 percent of the
with a long-term vision. Growing stock timber volume extracted from primary
of commercial timber species declines forests will be available for the next
substantially after a primary forest harvest, assuming that the number of
is harvested for the first time, and harvested species increases over time.
this does not recover to pre-harvest If the same species continue to be
levels within a practical timeframe. harvested, then only 35 percent of the
Furthermore, management for long- original stock will be available for the
term production is often not the most second cut and yield will likely continue
lucrative land use option (Putz et al., to decline thereafter (Putz et al.,
2012). As such, the general approach is 2012). Under the prevailing harvesting
to harvest revenue-generating high- protocols, the current felling cycles are
value timber as quickly as possible, too short by a factor of at least two, and
moving to lesser-value species in therefore would need to be lengthened
subsequent harvests, until the economic to 50–100 years to sustain yields
value of the forest is depleted. (Zimmerman and Kormos, 2012; Putz
et al., 2012).
4.2 Post-harvest recovery and
rotation cycles 4.3 Impact of selective logging
Where tropical forest management and fixed harvest regulations
focuses mainly on timber production, During selective logging, the most
the main objective is to sustain timber valuable tree species are removed in one
yield. After harvesting, the commercial or several harvesting operations. When
growing stock is expected to recover the most valuable species in an area
over the felling cycle, which is typically have been exhausted, the next group
20 to 40 years (Putz et al., 2012). of valuable tree species are extracted.
The crucial question is whether the This shifting of biomass increment from
mandated rotation period is sufficient high-value timber species to lower-
to allow this recovery to happen. value species (called high grading)
Sustainability in timber production is reduces the economic value of the stand.
achieved when the same amount of The disappearance of certain timber
wood as harvested in each felling cycle species, which are often the dominant
is replenished over the rotation period. canopy trees, also has a negative
From an ecological and environmental ecological impact and impoverishes
point of view, SFM requires that the species diversity. The impact of selective
provision of forest goods and services logging on the forest depends mainly
does not decline over time. This means on the harvest intensity, measured
that forests should not be affected by by the number of trees harvested or
interventions in their resilience, and cubic metres extracted per hectare.
should have the same structure, timber With increasing intensity of harvest,
volume, biodiversity, biomass and damage to the remaining stand increases
ecological processes as before harvesting (Zimmerman and Kormos, 2012).
(although an exception may have to Government protocols on SFM often
be made for the first time a primary mandate fixed limits on harvesting, such
forest is logged as it is unlikely that the as minimum cutting cycle, minimum
forest can return to the original pristine felling diameter, maximum harvest
8Part 1: SUSTAINABLE MANAGEMENT OF TROPICAL PRODUCTION FORESTS
intensity, and retention of seed trees.
Minimum cutting cycles of 25 to 35 years
and minimum harvesting diameter of
50 cm are common. Various studies have
investigated the sustainability of current
cutting cycles and harvest intensities in
tropical forests, and concluded that the
prevailing management practices with
static limits on harvesting are unlikely
©Sebastian Gräfe
to be sustainable (Macpherson et al.,
2012; Piponiot et al., 2019; ter Steege
et al., 2002; Huth and Ditzer, 2001;
Kammesheidt et al., 2001; Hall et al.,
2003; Sist et al., 2003; Dauber et al.,
2005; Zimmerman and Kormos, 2012). Marked future crop tree in Suriname.
Reducing harvest intensity, for
example by increasing minimum felling
diameter, lowering annual allowable cut Commercial timber species in tropical forests
or retaining more large-diameter trees, are often present in low densities and show
would help sustain production. Leaving clumped distribution patterns influenced by
more marketable trees in the forest biophysical requirements for regeneration
represents opportunity cost for the and habitat preference. In many cases,
forest managers, and this would reduce natural regeneration is inadequate, and
the economic feasibility of operations. silvicultural treatments are needed to
Furthermore, lower harvest intensity ensure recruitment and regrowth of the
may not increase the regeneration of harvested species after logging.
light-demanding timber species which FCT release is mainly used in North
dominate the tropical timber market. America and Europe to positively
Higher harvesting intensity on the influence the growth of selected crop
other hand would lead to larger and trees identified in the early stages of stand
more frequent canopy gaps, promoting development (Abetz, 1990; Abetz and
vigorous regeneration of pioneer species Klädtke, 2002; Burschel and Huss, 2003).
with no commercial value. Ideally, By eliminating crown competition from
harvesting protocols should be designed neighbouring trees, the FCTs are provided
for each harvested species, considering with more growing space. Release of FCTs
its life history, including regeneration directs limited resources, including light,
ecology, growth rates, distribution water and soil nutrients, of a given forest
and size composition. The challenge, site to a smaller number of selected trees.
however, is that such data are not readily This accelerates the growth of FCTs and
available, even for the most valuable shortens the time until these trees reach
commercial timber species. the final harvesting diameter (Dawkins,
1955; Wadsworth and Zweede, 2006;
4.4 Effects of silvicultural Smith, 1997).
treatments The stimulation of tree growth by release
Silvicultural treatments, including treatments in temperate forests has been
enrichment planting, removal of confirmed by numerous studies (e.g. Hein
lianas, girdling of unwanted trees and et al., 2007a; Hein et al., 2008; Hein et al.,
liberation felling, have been tested and 2007b; Herbstritt et al., 2006; Mäkinen and
implemented in the tropics to increase Isomäki, 2004). Several studies examined the
the production of high-value timber. effect of silvicultural treatments in tropical
9Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity
forests, where growth increases of 20 to mitigation actions through public and
60 percent were observed (Wadsworth private finance, both market- and non-
and Zweede, 2006; Villegas et al., 2009; market-based (FAO, 2018). Results-based
Peña-Claros et al., 2008; Kuusipalo et al., payments are the final phase in REDD+
1997; Werger 2011). Graaf et al. (1999) where developing countries receive
had carried out silvicultural treatments financial rewards for measured, reported
in Suriname since 1965. They reduced and verified REDD+ results (UNFCCC,
the basal area of non-marketable tree 2020).
species from 20 m2/ha to 6 m2/ha and the The aim of SFM is to maintain and
total basal area to 10 m2/ha. The effects enhance the multiple values of forests
of these treatments lasted for less than over generations. It is, therefore,
10 years and even with short cutting fundamentally important for REDD+;
cycles of 20 to 30 years, the treatments in many countries it will be an essential
were only effective if they were repeated. means for achieving the objectives of
The mortality rate increased as the curbing emissions from deforestation
intensity of the treatments increased. and forest degradation and conserving,
David et al. (2019) found that the managing and enhancing forest carbon
magnitude of the liberation effect on stocks. REDD+ offers opportunities for
the remaining stand depends strongly restoring forests where they have been
on the tree species. Studies on the effect lost or degraded and thereby bringing
of logging and crown liberation on the more land under SFM. REDD+ may also
population dynamics of tree seedlings generate additional revenue to broaden
show that canopy release favours the financial base for forest conservation
the recruitment of light-demanding and sustainable management, increase
pioneer species rather than promoting the benefits deriving from forests and
the regrowth of the desired timber trees, and encourage the wider uptake
stock (Zimmerman and Kormos, 2012; of SFM (FAO, 2020c).
Kuusipalo et al., 1996). The following five REDD+ activities
have been globally agreed to contribute
to forest-related mitigation actions:
5. SUSTAINABLE FOREST 1. reducing emissions from deforestation;
MANAGEMENT AND REDD+ 2. reducing emissions from
Reducing emissions from deforestation forest degradation;
and forest degradation, plus the 3. the conservation of forest
sustainable management of forests, carbon stocks;
and the conservation and enhancement 4. the sustainable management of forests;
of forest carbon stocks (REDD+), is an and
essential part of the global efforts to 5. the enhancement of forest carbon
mitigate climate change. The aim of stocks.
REDD+ is to encourage developing
countries to contribute to climate-change These five activities can best be
mitigation by: 1) reducing greenhouse implemented through a package of
gas (GHG) emissions by slowing, coordinated policies and measures
halting and reversing forest loss and defined by each country and included in
degradation; and 2) increasing removals national strategies and action plans.
of GHGs from the atmosphere through For sustainable management of
the conservation, management and forests, examples of REDD+ policies and
expansion of forests (UNFCCC, 2020). measures may include:
Countries are adopting diverse • bringing more forests under
approaches to finance their REDD+ sustainable management;
10Part 1: SUSTAINABLE MANAGEMENT OF TROPICAL PRODUCTION FORESTS
• implementing payment schemes for rates and response to treatments,
the environmental services rendered carbon sequestration in above- and
by forests; below-ground biomass; emissions due to
• strengthening community forest forest operations; emissions related to
management; or harvesting of trees; and the duration of
• obtaining forest certification. forest management cycle.
FCT release will shift the growth
Despite the obvious synergies increment from non-commercial trees
between SFM and REDD+ objectives, to high-value timber species, improving
only a few countries have included productivity and sustainability of yield.
sustainable management of forests In addition, such silvicultural treatments
under their national REDD+ activities might strengthen the financial basis
due to complexities in measuring of forest management to prevent
increases in forest carbon stocks and conversion to other land uses. However,
sequestration due to improved forest the principal objective of REDD+ is to
management practices as measured reduce GHG emissions, and carbon is
against forest reference (emission) levels valued at the same price regardless of
(FAO, 2020d). the composition of trees that comprise
This paper assess the potential impact forest biomass. There is a need to
of silvicultural practices, specifically better understand the trade-offs
FCT release treatment, to improve among different forest management
productivity of logged forests while objectives, the impact of silviculture
conserving and enhancing forest carbon treatments on carbon emissions and
stocks. The evaluation of carbon benefits absorption, and the synergies between
of different forest management practices REDD+ and SFM, both of which are
needs to consider: species-specific growth multifaceted.
©Benjamin Bindewald
Landscape dominated by degraded forests in Trinidad and Tobago.
11Measuring diameter of a large tree above the buttress in Suriname. ©Bernhard Kenter/UHH
Part 2: THE CARIBBEAN CASE STUDIES
Lowland tropical rain forests covered and forest-related activities represent
much of the Caribbean countries prior the only income opportunities in many
to the arrival of Europeans in the 15th hinterland communities in the case study
century. Colonization of the New World countries.
by Europeans brought significant Forest management practices in the
changes to the Caribbean, and many of Caribbean have been driven by the need
the countries were heavily deforested to generate and maximize short-term
for commercial agriculture. There was revenues. Intensive forest management,
also intensive exploitation of timber including silvicultural interventions,
resources starting in the 18th century. is likely to be more expensive than
In the past half century, conversion conventional forest exploitation. In
for agriculture – both commercial and order to make economic sense, the
subsistence – urban development, additional costs of implementing
mining, timber harvesting, fuelwood improved forest management must be
collection, etc., have continued to balanced by increase in productivity
drive deforestation and degradation of and potential payments for ecosystem
forests. In recent decades, forest cover services including carbon.
has stabilized in many countries, and To guide the sustainable use and
there is increased recognition of the management of these often-neglected
importance of forests for watershed forest resources, the project “Ensuring
protection, biodiversity, recreation and
resilience. The current forest extent,
condition and level of production vary
widely among the countries.
Even though the ecological integrity
of these previously harvested forests has
been substantially affected, the forests
still constitute a valuable resource. In
most cases, these forests are located
in relatively accessible areas and still
contain several tree species that provide
valuable timber despite their modified
©Sebastian Gräfe
species composition. Intensive forest
management can offer much needed
employment opportunities in rural areas
and can contribute significantly to the
reduction of poverty and hunger. Apart
from subsistence agriculture, forestry A large tree in a tropical forest in Suriname.
13Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity
Long-Term Productivity of Lowland In all four countries, forests have
Tropical Forests in the Caribbean” been managed and timber harvested
sought to address the following commercially since the mid-19th century.
questions: However, there are considerable
1. Do the logged-over forests contain differences among the project countries
sufficient timber resources to sustain in the current extent and condition
further harvesting? of their forests. In countries with low
2. Can silvicultural treatments increase population density, namely Guyana and
the productivity of these forests? If Suriname, large tracts of forest remain
so, what are the expected costs and mostly untouched, as logging operations
benefits of these interventions? have only affected certain designated
3. What is the impact of these areas. On the other hand, on the island of
silvicultural treatments on forest Trinidad, with a high population density
carbon stocks, and is there a scope for and a high demand for agricultural land,
obtaining additional revenues from most of the original forest cover has
carbon financial mechanisms? been removed and the remaining forests
are severely degraded. Forests in Belize
have been heavily exploited in the past,
1. APPROACH AND mostly for mahogany. Of the four project
METHODOLOGY countries, Belize is the only country
Four countries were selected to that is currently experiencing relatively
investigate the sustainability of high rates of deforestation, mostly due
silvicultural interventions to improve to agricultural expansion. There are
forest management in lowland tropical significant levels of forest production
forests in the Caribbean: Belize, Guyana, in Guyana and Suriname, where forest
Suriname, and Trinidad and Tobago. The products constitute an important export
climate of these countries is tropical and commodity, while there is limited forest
characterized by pronounced dry and harvesting in Belize and Trinidad and
rainy seasons. While Belize and Trinidad Tobago (Table 1).
and Tobago have a dry season from In the four project countries, a total
January to May, Guyana and Suriname of ten 100-ha test sites were established
have two rainy seasons, from February for an extensive forest inventory
to April and from August to November, (Table 2). The participating national
with dry seasons in between. In Belize forest authorities were responsible
and Trinidad and Tobago, forests are for the site selection based on specific
also threatened by hurricanes. interests and context of the country.
Table 1. Status of forests and forest production in the project countries
Country Forest area Forest area Carbon stock Total Value of forest
(1 000 ha) and change (tonnes/ha) roundwood products
cover 2000–2020 production exported in 2019
(1 000 ha) in 2019 (m3) (1 000 USD)
Belize 1 277 (56%) -182 (-12.5%) 123 167 000 3 715
Guyana 18 415 (94%) -149 (-0.8%) 396 1 137 022 39 583
Suriname 15 196 (97%) -146 (-0.9%) 220 1 170 981 88 372
Trinidad and 228 (45%) -8 (-0.4%) 53 197 259 2 302
Tobago
Source: FAO, 2020a and FAOSTAT.
14Part 2: THE CARIBBEAN CASE STUDIES
Table 2. Study sites and tenure types
Country Site Silvicultural System/Logging Type Ownership Tenure Type Cutting
Cycle
Belize Rio Bravo 305 Polycyclic/controlled selective logging Private Privately 40 years
based on minimum harvesting diameter forest managed
Rio Bravo 102 (MHD) and maximum allowable cut
(MAC) from yield model
Quiche Ha Polycyclic/conventional selective logging State forest Community 1 year
managed with
Guyana Great Falls Polycyclic/conventional selective logging annual cutting
based on MHD permits
Orealla
Ituni
Suriname Mapane Polycyclic/controlled selective logging State forest Large-scale 30 years
based on MHD and fixed MAC concession
Kabo Polycyclic/semi-controlled selective
logging based on MHD and fixed MAC
Trinidad Rio Claro Polycyclic/conventional selective logging State forest Periodic block 30 years
and based on MHD with individual tree sale system
Tobago Cats Hill
©Kenichi Shono/FAO
An abandoned steam engine used for hauling logs in Rio Bravo Conservation Area, Belize.
In all test sites, logging was practised types and conditions that exist in the
at least once within the past 30 years project countries, but represent the key
and planned to be carried out again common forest tenure types found in
within the project period, and the the Caribbean region, which are:
participation of concessionaires, forest 1. large-scale concession managed forest
owners or communities with granted 2. periodic block system
tenure was secured. The test sites do 3. privately-owned forest
not cover the entire range of forest 4. community-managed forest.
15Sustainable management of logged tropical forests in the Caribbean to ensure long-term productivity
Box 1 Forest tenure types covered by the study sites
Large-scale concession
The management of large-scale concessions included in this study is based on
annual cutting areas of 100 ha with pre-harvest inventory, planned skidding
and directional felling. The concessionaire prepares a management plan, which
is approved by the national forest authority prior to harvesting. Harvesting
follows guidelines published by the respective forest authority which include
maximum allowable cut per hectare (normally between 20 and 25 m3/ha) with
a rotation period of 30 years, minimum distance of 10 m between harvested
trees, protection of soil, water and conservation values, block alignment and the
maximum area of roads to be constructed in a felling compartment (Blaser and
ITTO, 2011). The restrictions listed above were gradually introduced over the
last 20 to 40 years. In the past, there were fewer restrictions on harvesting, but
only large-diameter trees of a few selected species were marketable and the rest
remained untouched in the forest. Hardly any trees under the diameter of 60 cm
were felled regardless of the stipulated minimum cutting diameter. In this way,
an economic cutting limit often replaced the regulatory limit. As a result, these
stands still remain relatively well stocked.
Periodic block system
The periodic block system is a polycyclic selective timber harvesting system. At least
one block per year is opened and the trees within the block are sold over a period
of two years. After two years the block is closed and allowed to regenerate without
interventions for a period of 30 years. The trees for sale are selected and marked
by forest officers following guidelines for tree selection. So-called replacement
trees are required for each harvest tree selected. Harvest and replacement trees
need to be of the same species. There is no pre-harvest inventory. Skid trails are not
pre-planned, but are created by the logging crew in an unplanned manner during
harvest operations. Although the amount of timber that can be removed from a
block during a 30-year cycle is fixed, there are blocks with clear signs of overuse,
which means trees not designated for utilization have been felled (Ramnarine et al.,
2002).
Privately-owned forest
The privately-owned forests in this study have been heavily harvested in the past.
The forest areas were exploited from the middle of the 19th century until 1982
under a logging concession licence (Shono and Snook, 2006). Logging was mainly
concentrated on mahogany without any management prescriptions. Minimum
cutting diameter was introduced only in 1992. The first forest inventory was
conducted in 1975 and showed that the commercial species volume had dropped to
36 m3/ha (PFB, 2016). Since 1988 the area has been managed by a non-governmental
organization, which uses a yield model developed based on the data of a network
of national permanent sample plots for the selection of harvest trees. Before
logging, the forest owner has to apply for a cutting permit by presenting an annual
plan of operations to the respective national forest authorities. A pre-harvest
inventory is mandatory, skid trails need to be pre-planned, and a post-harvest
inventory is executed after logging. The cutting cycle is 40 years (PFB, 2016).
16Part 2: THE CARIBBEAN CASE STUDIES
Community-managed forest
The communities participating in this study log their forest on an annual basis.
The forest is state-owned but managed by a community and harvested through
conventional logging. Cutting permits, called state forest permits, are granted
on an annual basis. The permit holder is not required to present a management
plan or to conduct pre-harvest activities such as pre-harvest inventory or skid
trail planning (Blaser and ITTO, 2011). Required measures for sustainable
management of the forest are written in a national code of practice, which was
adopted by a forests act in 2009 (Parliament of Guyana, 2009).
Figure 2. Study site design
Figure 2 presents the layout of the are located within this site, which contain
study sites, which follows a randomized 140 sample plots with a size of 0.5 ha
block design. With the exception of one each. The entire case study covers an area
site in Suriname, all study sites were of 10 km2 or 1 000 ha.
established according to Layout 1. Study On each site, a forest stock assessment
sites arranged according to Layout 1 cover (pre-harvest inventory) was implemented,
an area of 1 x 1 km. In each 1 x 1 km and the following characteristics collected
site, four blocks containing 32 plots of for all trees with a diameter at breast
50 x 100 m (0.5 ha) were established. The height (DBH) ≥ 25cm:
individual blocks and the entire 1 x 1 km • DBH
site are surrounded by a buffer-zone • position (GPS coordinates)
to avoid influences from neighbouring • log grade
stands. In Suriname, a modified block • species
design had to be used for one site due to • standing volume
the concessionaire’s pre-set logging area • harvestable timber volume
alignment. This site follows Layout 2 and In total more than 80 000 trees were
has a size of 0.8 x 1.25 km. Two blocks recorded over 1 000 ha.
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