Organizers: Sheila Ward (Mahogany for the Future, Puerto Rico/USA), Emmanuel Opuni-Frimpong (Forest Research Institute of Ghana) & Nicholas Brokaw (University of Puerto Rico)
Effects of tree species diversity on stem quality: plot and tree level results from six European regions. Benneter, A., Bauhus, J. (University of Freiburg, Germany; adam.benneter@waldbau.uni-freiburg.de; juergen.bauhus@waldbau.uni-freiburg.de).
Stem quality is infl uenced by a tree’s ability to capture suffi cient resources for growth and is infl uenced by neighboring trees, e.g., through shading and crown collisions. We collected data on crown size, stem form, and tree health for more than 12 000 trees in 210 study plots in six European regions (Finland, Germany, Poland, Romania, Italy, and Spain) within naturally diverse forests in order to assess the impact of tree species diversity on these characteristics. Results show that quality variability among regions, stands, and individual trees is high across species. On the stand level, there was a slight tendency towards lower stem quality with increasing diversity. However, individual trees of high quality were present in all diversity levels and for all target species. The infl uence of the immediate neighborhood’s species composition is modifi ed by a set of regional, individual, and stand characteristics. The neighborhood effect is likely the key factor regarding individual tree quality and, according to early results, quality is not negatively affected by diversity in neighborhoods. If this fi nding can be further validated, this study provides support for the hypothesis that diverse stands are capable of providing highly valuable timber while at the same time providing various other ecosystem services.
Enrichment of Central African logged forests with high-value tree species: testing a new approach in degraded forests.
Doucet, J. (University of Liege, Belgium; jldoucet@ulg.ac.be), Tekam, P., Lagoutte, P. (Pallisco SARL, Cameroon; patricetekam@
gmail.com; exploitation@pallisco-cifm.com), Dainou, K., Bourland, N. (University of Liege, Belgium; kdainou@ulg.ac.be;
nils.bourland@aigx.be), Ward, S. (Mahogany for the Future, Inc., USA; mahoganyforthefuture@gmail.com).
Enrichment of logging gaps in Central African forests provides contrasting outcomes for different species, since these gaps do not always optimally meet their ecological requirements. In order to bypass this diffi culty, we tested a new silvicultural method in south-eastern Cameroon. Multi-species plantations were implemented in 15 patches (0.2–1.1 ha) of degraded forest. Each plantation was divided into 225 m2 subplots and 25 seedlings of a given species were planted per subplot. Species varied between adjacent subplots to 1) match the light requirements of specifi c species with the degree of shade from remaining trees, 2) maintain biodiversity, and 3) prevent the spread of disease. Selected indigenous species included were either potentially threatened
(e.g., Pericopsis elata), useful non-timber (e.g., Irvingia gabonensis), heavily logged (e.g., Entandrophragma spp.), or suffering from a lack of regeneration (e.g., Triplochiton scleroxylon). Preliminary results usually indicated similar or better performance in these subplots than in enriched logging gaps. Since the cost of this silvicultural procedure was similar to that of logging gap enrichment, we suggest that both may be integrated to forest management strategies in order to ensure high structural and fl oristic diversity of the Congo Basin timber production forests.
Relationship between selected indicators of forest stand diversity and quality of timber production in even-aged and uneven-aged stands. Merganic, J., Merganicova, K., Marusak, R., Stolarikova, R., Tipmann, L., Dragoun, L. (Czech University of Life Sciences, Czech Republic; merganic@fl d.czu.cz; merganicova@fl d.czu.cz); marusak@fl d.czu.cz; stolarikova@fl d.czu.cz;
tipmann@fl d.czu.cz; dragoun@fl d.czu.cz).
The current trends in Central European forestry place strong emphasis on multipurpose utilisation of forests and their products.
Therefore, objective analyses that deal with contradictory society demands, such as timber production and diversity, are required.
The present study examines the connection between the quality of timber production and species and structural diversity of forest stands. The study is based on the regional forest inventory of the University Forest Establishment in Kostelec nad Černými lesy, Czech Republic. The inventory was performed from 2009 to 2011 on 1 188 sample plots that represented 86 strata defi ned on the basis of three variables: site (5 categories), age (12 categories), and canopy cover (5 categories). On every sample plot, we quantifi ed 171 partial biodiversity indicators. Quality of timber production was evaluated visually in the fi eld as an estimate of stem quality (3 classes) and in post-processing using local assortment tables (5 assortment classes). In total, we analysed 117 648 different variants of the relationship between the diversity indicator and the quality of timber production. The results indicate that the relationship between diversity and timber quality changes with the stand age or the developmental stage of forest stands.
Managing for high value timber and biodiversity in the Congo Basin. Nasi, R. (Center for International Forestry Research, Indonesia; r.nasi@cgiar.org), Van Vliet, N. (Center for International Forestry Research, Colombia; vanvlietnathalie@yahoo.com), Billand, A. (CIRAD, France; alain.billand@cirad.fr).
Multiple-use forest management is considered by many as a preferable alternative to single-use, generally timber-dominant, management models to ensure a greater biodiversity. In this presentation we will briefl y explore the major land-uses in the Congo Basin and their actual or potential for sustaining biodiversity in a production context. We then focus on the most extant produc-tion systems (shifting cultivaproduc-tion, industrial logging concessions, and main commodity crops) to analyze the existing issues and options for actively managing both valuable timber species and biodiversity with a special emphasis timber stands, wildlife, and the potential role of certifi cation. We highlight a few promising but yet unfi nished examples in the region and we review these cases to draw lessons and recommendations. We contend, however, that true multiple-use could only be realized by expanding beyond boundaries of formal management units through new innovative land-use units, allowing a spatial cohabitation of the interests of local people, of conservation proponents and of extractive industries in the same management unit.
Restoration of degraded lands with mahogany in mixed-species plantations promotes biodiversity and conservation of valuable timber species. Opuni Frimpong, E., Nyarko-Duah, N., Opoku, S (Forestry Research Institute of Ghana; eopunifr@mtu.
edu; nayanyd@yahoo.com; pokoyour@gmail.com), Storer, A. (Michigan Technological University, USA; storer@mtu.edu), Burton, A. (Forestry Research Institute of Ghana; ajburton@mtu.edu).
The need to restore the African mahogany and other valuable timbers in degraded landscapes of the Upper Guinean forest of Ghana is very urgent. Ecologists, sivilculturists, geneticists, entomologists, and other professionals in forestry are undertaking various studies towards developing systems to restore degraded lands with forest cover that will have the ecological integrity and biodiversity which are the desired character of the tropical forest. Restoration of the African mahogany, which naturally grows well in the diverse tropical forest, was hampered in plantations with monocultures by severe mahogany shoot borer, Hypsypyla robusta (Moore) attacks. Studies were conducted across three ecological regions in Ghana where mahogany grows naturally to assess the performance of this valuable timber species in plantations of mixed timber species compared to pure stands. The studies reveal that mixed cultures not only promoted restoration of biodiversity in forest landscapes but also reduced damage by the ubiquitous shoot borer. The observed reduction in attack was not the same across the three major ecological regions of Ghana.
Conservation of mahogany in plantations and other landscapes may require plantings with diversifi ed species to reduced pest attack and improve the desired tree forms of mahogany.
Combining high-quality timber production, biodiversity conservation and forest aesthetics: the case of Sorbus species in Europe. Skovsgaard, J. (Swedish University of Agricultural Sciences, Sweden; jps@slu.se).
Some Sorbus species such as S. aucuparia are among the most abundant tree species in the forest and landscape throughout Europe, while others such as S. domestica and S. torminalis are among the rarest. The group of rare species also includes a large range of local hybrids or so-called micro-species that are often red-listed. Those species that are found mainly in the forest are generally managed for their contribution to biodiversity (rare species) and forest aesthetics (fl owers and autumn foliage) or simply disregarded or considered inferior in silviculture. Nevertheless, species like S. torminalis and S. domestica represent a consider-able potential for economic forestry as their timbers are among the highest valued in the market. Based on recent research results and experience from forestry practice this presentation reviews the options and obstacles for combining high-quality timber production with biodiversity conservation and forest aesthetics. Natural regeneration and planting for re- or afforestation are given special attention as these processes are crucial for enlarging the representation and improving the quality of Sorbus forest species in Europe.
Posters
Effects of overstory species diversity and composition on pest damage to high value species and understory ant diversity in Ghana. Bosu, P. (Forestry Research Institute of Ghana; paul_bosu@yahoo.com), Stephens, S. (Colorado State Forest Service, USA; S.stephens@colostate.edu), Wagner, M. (Northern Arizona University, USA; Mike.wagner@nau.edu).
Experimental mixed-species and pure plantations were established using 11 native timber species in various combinations and ratios to evaluate the impact of the mixtures on endemic pests of three high value species (Milicia excelsa, Khaya ivorensis, and Pericopsis elata) and diversity of ground foraging ant species in the plantations. Although pest incidence was still prevalent in all the plantations after 2 years, the level of damage reduction achieved was, in many instances, enough to sustain the vulnerable species through critical growth stages. Results from a pitfall trapping of ants showed no signifi cant differences in traditional diversity measures or functional group composition between treatments 1 year after planting. However, 2 years after planting we found signifi cant differences in species richness. Several trends were observed that may indicate that these ant communities are currently in transition and will likely become more distinct over time as the plantations develop.
Cedrela montana in tropical montane rain forests of southern Ecuador: key species for sustainable management and conservation of biodiversity hotspots? Guenter, S. (Thünen Institute of International Forestry and Forest Economics, Germany;
sven_gunter@yahoo.de), Hildebrandt, P., Calvas, B. (Munich University of Technology, Germany; hildebrandt@mytum.de;
baltacha_c@yahoo.es), Segura Ramos, D. (Ministry of the Environment, Ecuador; dsegura@ambiente.gob.ec).
The Andean forests of southern Ecuador are highly threatened ecosystems affected by increasing rates of deforestation. Cedrela montana, as one of the most valuable tree species in Ecuadorian montane rain forest, could play a key role in establishing silvicultural systems for sustainable forest management. During 10 years of research at the Estación Cientifi ca San Francisco we gathered a pool of data about the ecology and silviculture of this species based on permanent plots of about 11 ha. While other species such as podocarps are of similar timber value, our results indicated a higher economic potential of C. montana due to better growth rates and higher abundance, though not yet abundant enough for establishing species-specifi c silvicultural systems.
However, our results revealed that mature diameter growth could not be improved by silvicultural treatments. Trials with assisted regeneration showed best performance of seedlings for canopy openness of about 20% in the fi rst years indicating a certain potential for enrichment plantings. Increased mortality in later years indicates that further interventions may be necessary in order to sustain growth and foster survival. Based on the 2013 national forestry inventory, we discuss how silviculture of C. montana could contribute to conservation of southern Ecuador as a biodiversity hot spot.
Restoration of high-value broadleaved forests in southern Sweden: synergistic effects on biodiversity and economy. Löf, M.
(Swedish University of Agricultural Sciences, Sweden; magnus.lof@slu.se).
Restoration of broadleaved forests in southern Sweden is a key issue for many threatened species and also for sustainable timber production, adaptation of forest management to climate change, and for social values. The governmental goals include increasing the area of these ecosystems using economic support systems for management of high-value timber tree species, increasing biodiversity, and ecosystem resilience. This is in contrast to short-term management goals of many private forest owners in the region, who depend on high volume growth of forests. Afforestation with broadleaves using planting or direct seeding is one method of restoration. Rehabilitation using enrichment planting or natural regeneration for conversion of conifer monocultures to broadleaves are other examples. In most cases, restoration of these broadleaved forests is very expensive. Therefore, there is an urgent need for new cost-effi cient regeneration and management methods. It is almost impossible due to incomplete knowledge of past forest states, climate change, and economic aspects to return the forest to its original state. A broad conception of restoration allowing more diverse goals, pragmatic approaches including economic aspects for the private forest owner, and innovative harvesting systems will be discussed.
Steniscadia poliophaea (Noctuidae) is a major seedling herbivore of big-leaf mahogany trees in Amazonian forests.
Norghauer, J. (University of Bern, Switzerland; julian.norghauer@ips.unibe.ch), Free, C. (Rutgers University, USA;
cfree14@gmail.com), Grogan, J. (Mount Holyoke College, USA; jgrogan@crocker.com).
We present the intriguing case of a moth, Steniscadia poliophaea, which only eats expanding leaves of seedlings and saplings of big-leaf mahogany (Swietenia macrophylla). This moth occurs in Brazil (Pará, Acre) and Peru, but apparently not in Central America or Mexico. We added mahogany seeds over 3 years into canopy gaps in unlogged forest (Pinkaití, Pará) to test for Janzen-Connell (JC) effects on recruitment as driven by vertebrate seed predators and this specialist moth herbivore. Data was used in a new growth and yield model to test whether these predators can limit the population size of mahogany. Including JC effects on fi rst year recruitment and JC effects from the moth on subsequent seedling growth and mortality capped the number of adults (≥30 cm diameter) at 30 trees/100 ha, leveling population growth. We conclude that S. poliophaea is an underappreciated pest of mahogany in Amazonian forests. Without silviculture to protect vigorously growing seedlings and saplings from this enemy, natural recruitment will be limited to scattered gaps far downwind of adults. Attack by these pests thus may result in very large areas of forests needed to sustain mahogany regeneration and yield, indirectly safeguarding forest biodiversity. We will also explore these consequences.
Can monoculture forest plantation harbor biodiversity similar to naturally regenerated tropical rainforest ecosystems over time? Onyekwelu, J., Olabiwonnu, A. (Federal University of Technology, Nigeria; onyekwelujc@yahoo.co.uk;
adezhollax@yahoo.com).
Little is known about the potential of forest plantations to conserve biodiversity. This study assessed biodiversity conservation in Gmelina arborea plantations, which was compared with those of degraded and primary rainforests. Overstory, sapling, and seedling species were inventoried in eight 400-m2-sample plots, 25-m2-quadrants and 4-m2 sub-quadrants, respectively. Eight tree species belonging to 7 families; 13 species to 10 families, and 24 species to 17 families were encountered in Gmelina plantation overstory, sapling, and seedling layers, respectively. Biodiversity indices were signifi cantly lower in Gmelina plantation overstory than primary and degraded forests. However, biodiversity indices of the sapling layers of Gmelina plantation and the natural forests were not signifi cantly different. Family and species diversities were signifi cantly lower in Gmelina plantation overstory (8, 7) than primary (8, 28) and degraded (18, 30) forest overstories. At the sapling layer, family and species diversities of Gmelina plantations (10, 13) compared favourably with those of primary (9, 15) and degraded (9, 16) forests. Species richness
was 24, 18, and 25 at seedling layers of Gmelina plantation, primary, and degraded forests, respectively. Twenty fi ve percent of species found in seedling layer of Gmelina plantation were absent in natural forests. Thus, plantation understory harbours high biodiversity, with the ability to conserve biodiversity over time.
Growth and productivity of Khaya grandifoliola in the dry semi-deciduous forest of Ghana: a comparison in pure and diverse species stands. Opuni Frimpong, E., Opoku, S. (Forestry Research Institute of Ghana; eopunifr@mtu.edu;
pokoyour@gmail.com), Owusu, S. (Michigan Technological University, USA; saowusu@mtu.edu), Burton, A. (Forestry Research Institute of Ghana; ajburton@mtu.edu), Storer, A. (Michigan Technological University, USA; storer@mtu.edu).
This study compares the growth and productivity of Khaya grandifoliola in mixed and pure plantations to that of Tectona grandis in pure stands. The plantation was set up with pure K. grandifoliola plots; mixed species plots of K. grandifoliola, Terminalia ivorensis, and Cedrela odorata; and pure Tectona grandis plots. The results 5 years after planting in the fi eld indicate that there was better diameter growth for K. grandifoliola in pure than in mixed stands. However, the total height and merchantable height growth of K. grandifoliola were not statistically different between the pure and mixed stands. Khaya grandifoliola performed better in pure than in mixed stands for basal area and volume. Khaya grandifoliola had more branches in the pure than in the mixed stands, but there were no differences in the level of Hypsipyla attack. There was no signifi cant difference in diameter growth between K. grandifoliola and Tectona grandis in pure stands. In spite of the vulnerability of K. grandifoliola to pest attack, its growth and productivity compared favourably to teak, an exotic species with negative impacts on biodiversity. Thus K. grandifoliola is a suitable plantation species for mitigation against climate change and for conservation of diversity in mixed plantations.
Single-tree management for high-value timber species in a mixed conifer-hardwood forest in northern Japan. Owari, T., Okamura, K., Fukushi, K., Kasahara, H., Tatsumi, S. (University of Tokyo, Japan; owari@uf.a.u-tokyo.ac.jp; kokam@uf.a.u-tokyo.
ac.jp; kfukushi@uf.a.u-tokyo.ac.jp; kasa@uf.a.u-tokyo.ac.jp; jeyms23@gmail.com).
High-value hardwoods such as monarch birch (Betula maximowicziana) and castor aralia (Kalopanax pictus) are important elements of cool-temperate mixed forests in Hokkaido, northern Japan. The production of fancy wood from these species brings signifi cant income through extremely high log prices (max. >20 000 USD/m3), and the presence of large-sized canopy trees in a stand may offer great ecological value. A single-tree management system for high-value hardwoods has been applied at the University of Tokyo Hokkaido Forest, where nearly 2 000 trees having superior quality are registered as high-value trees. All trees are numbered, and the DBH, species name, vitality, and stem damages (if any) are recorded. The geographic locations of each individual are identifi ed using the global navigation satellite system. The status of high-value trees is continually observed so as to harvest them at the proper time. To explore how the single-tree management for high-value timber species contributes to maintain the structural diversity of forests, we examined the structural attributes (e.g., species composition, diameter distribution) of the stands in which registered high-value trees are located.
Comparison of species composition and stand structure between a secondary forest and a mahogany plantation on Mt.
Makiling. Park, P., Han, A. (Seoul National University, Republic of Korea; pspark@snu.ac.kr; phoya@naver.com), Barile, J.
(Makiling Center for Mountain Ecosystems, Philippines; jojobarile@yahoo.com), Lee, Y. (Korea Forest Service, Republic of Korea; shorea@foa.go.kr), Gadia, G., Lee, D. (Seoul National University, Republic of Korea; gelliegadia@gmail.com;
leedk@snu.ac.kr).
Mahogany plantations are favored in tropical countries for their capacity to facilitate increases in carbon sequestration and biomass accumulation as well as economic income of the land. High biodiversity is the most distinct characteristic of tropical forests while plantations are increasing for many reasons. This study compared species composition and stand structure between a mahogany plantation and a secondary natural forest to provide better options for forest practices. In addition, monthly litter fall biomass was monitored to investigate temporal processes in the secondary forest. The secondary forest had more than twice as many woody species as the mahogany plantation. The secondary forest showed a reverse J-shaped height distribution and a multi-canopy structure with the overstory of 20–25 m with a few emergents, and mid multi-canopy layer of 10–20 m. The overstory layer in the mahogany plantation ranged from 30 to 35 m. The litter fall production peaked in May or June, and also increased between September and November. Flower and fruit biomass was about 3 and 20% of the leaf litter biomass, respectively. Silvicultural prescriptions to consider the diverse structure and complex processes of natural forests should be developed to counterbalance the decrease in tropical natural forests.
Growth and stem quality of oak trees established in cluster plantings respond differently to intra- and interspecifi c neighbourhood competition. Saha, S., Kühne, C., Bauhus, J. (University of Freiburg, Germany; somidh.saha@waldbau.uni-freiburg.de; christian.kuehne@waldbau.uni-somidh.saha@waldbau.uni-freiburg.de; juergen.bauhus@waldbau.uni-freiburg.de).
Growth and stem quality of oak trees established in cluster plantings respond differently to intra- and interspecifi c neighbourhood competition. Saha, S., Kühne, C., Bauhus, J. (University of Freiburg, Germany; somidh.saha@waldbau.uni-freiburg.de; christian.kuehne@waldbau.uni-somidh.saha@waldbau.uni-freiburg.de; juergen.bauhus@waldbau.uni-freiburg.de).