Adaptation of Tropical and Subtropical Pine Plantation Forestry to Climate
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Title: Adaptation of tropical and subtropical pine plantation forestry to climate change: realignment of Pinus patula and Pinus tecunumanii genotypes to 2020 planting site climates. Running headline: Tropical pine plantations and climate change Corresponding author Mr. Christoph Leibing Zentrum Holzwirtschaft, Universität Hamburg, Leuschnerstrasse 91, D‐21031, Hamburg, Germany Fax: +494030031770 Telephone: +494030031770 E‐mail: [email protected] Co‐authors Mr. Maarten van Zonneveld Bioversity International, Americas office, km 17 recta Cali/ Palmira, PO 6713, Cali, Colombia. Dr. Andrew Jarvis International Centre of Tropical Agriculture (CIAT) and Bioversity International, km 17 recta Cali/ Palmira, PO 6713, Cali, Colombia. Dr. William Dvorak Central America and Mexico Coniferous Resources Cooperative (CAMCORE), North Carolina State University, 2720 Faucette Drive, 3229 Jordan Hall Addition, Raleigh, North Carolina 12 27695‐8008 Suggested Reviewers (1) Cuauhtemoc Saenz Romero, Universidad Michoacana de San Nicolás de Hidalgo [email protected] Dr. Saenz‐Romero has a large list of references of research on Mexican pine species, and has also carried out research about the impact of climate change on these species. He was referred to two times in the manuscript. (2) Robert Hijmans, IRRI [email protected] Dr. Hijmans is an expert in GIS and published many articles about modeling species’ climatic niches. He is referred to in the article and is also the principal developer of the DIVA‐GIS program. (3) David L. Spittlehouse, British Columbia Ministry of Forests and Range [email protected] David Spittlehouse published many articles on forest management adaptation to climate change. He is referred to three times in this article. (4) Erik Dahl Kjær, Forest and Landscape, Denmark [email protected] Professor Kjaer is an expert in the field of sustainable forest and landscape management in the face of climate change. He has a long history of working with multisite provenance trials. (5) Michael Köhl, World Forestry, Hamburg [email protected] Professor Michael Köhl is a specialist for quantitative methods and published many articles in this field. His active research areas are forests and climate change and forest growth modeling. 1 2 1 Abstract 2 Pinus patula and Pinus tecunumanii, two pines native from Mexico and Central America are 3 important plantation species for the forestry sector in the (sub)tropics. In the last decades members 4 of the International Tree Conservation & Domestication Program (CAMCORE), North Carolina State 5 University, have established large multi site provenance trials for these pine species. The data 6 provide valuable information about species and provenance choice for plantation establishment in 7 many regions with different climates. However, since climate is changing rapidly, it might become 8 increasingly difficult to choose the right species and provenance to plant. The aim of the study is to 9 test the suitability of seed material under changing climate of two P. patula varieties, P. patula var. 10 patula and P. patula var. longipedunculata, and two P. tecunumanii ecotypes (highland and lowland). 11 For each variety and ecotype, a site growth model was developed that statistically relates growth 12 with environmental factors and couples the predictions to the average 2020 climate prediction of 13 four general circulation models. Three developed models were significant and robust. Provenances 14 of P. tecunumanii from lowland areas in Central America are expected to be most productive in 2020 15 because of their promising performance under rather hot and wet climates. 16 17 Keywords: climate change impact predictions, management decision support tools, provenance 18 trials, site growth modeling, height growth 19 3 20 Introduction 21 22 Global climate alterations will likely impact productivity of plantation forestry in the next decades. 23 Forest growth models suggest substantial loss of production in the core area of current forestry if no 24 appropriate actions are taken (Fairbanks, 1999; Spittlehouse & Stewart, 2003). At the same time 25 planted forests become increasingly important to satisfy global wood demand (Carle & Holmgren, 26 2008). Planted forests may also indirectly reduce pressures in natural forests and are potential 27 sources for carbon sequestration (Carle & Holmgren, 2008), and in that way contribute to the 28 mitigation of climate change. To assure the supply of the expected products and services from 29 planted forests in the next decades under changing climate, plantation forest management needs to 30 be adapted accordingly. 31 32 The selection of species and provenances that are most suitable to grow under the new climates 33 that are expected to occur is an important aspect of a management plan that aims to adapt 34 plantation forests (Spittlehouse & Stewart, 2003). It can be anticipated that seed material used in 35 the past decades to establish new plantations will not be optimal under the changing climate in the 36 next decades. New sources of seed will need to be found to optimize wood productivity. 37 38 In the last decades multi‐site provenance trials have been established to identify which are most 39 suitable species and provenances to plant in different climates (e.g. Dvorak et al. 1995; Hodge & 40 Dvorak, 1999, Kanzler, 2002). Site growth modeling has proved to be a practical and accurate 41 method to predict the performance of species and provenance in these experiments (Louw & 42 Scholes, 2004). Support decision models that couple site growth modeling to future climate 43 predictions based on General Circulation Models (GCMs) can be a useful tool for forest managers to 44 choose which provenances and species to plant today in order to yield optimal growth during the 45 rotations in the following decades. 46 47 Significant areas of planted forests are grown in tropical and subtropical areas of Colombia, Brazil 48 and South Africa (FAO, 2007). Pinus patula and Pinus tecunumanii, two pine species native to Mexico 49 and Central America are important plantation species for the forestry sector in the tropics and 50 austral regions. In the last decades the members of the International Tree conservation & 51 domestication Program(CAMCORE) have established multi‐site provenance trials on a global level 52 that include 74 trials and 79 trials of P. patula and P. tecunumanii, respectively, to identify the 53 growth and survival of these species and provenances across different environments. The results 54 from these trials represent a treasure trove of data suitable for understanding how trees are 55 adapted to their abiotic environment, and how they adapt to different conditions. 56 57 P. patula is one of the most important pine plantation species in tropical and subtropical regions 58 with close to one million hectares established in plantation (Birks and Barnes, 1991). It is of primary 59 importance in South Africa where the pine is the most commonly planted species accounting for 60 25% of the country’s entire forest plantation area (FAO, 2007). Lesser amounts of P. tecunumanii are 61 used in plantations, but it is an important plantation species in Colombia, and due to its favourable 62 growth characteristics and comparatively high resistance against pitch canker (Hodge & Dvorak, 63 2006) the species is also gaining importance in Brazil and southern Africa (Dvorak et al. 2000). 64 65 P. patula, occurs naturally in the mountainous regions of eastern and southern Mexico. Two 66 varieties can be distinguished: P. patula var. patula which occurs in the eastern mountain ranges of 67 the Sierra Madre Oriental and P. patula var. longipendiculata which occurs in the southern Mexican 68 states of Guerrero and Oaxaca in the Sierra Madre del Sur (Dvorak et al., 2000). The geographical 69 distribution of P. patula var. longipendiculata borders with the western distribution range of P. 70 tecunumanii. P. tecunumanii distribution extends from Chiapas, Mexico in the north to Honduras in 71 the south and can be divided into two ecotypes based on altitude: a highland ecotype found in cloud 4 72 forests between altitudes of 1500–2900 m, and a lowland ecotype that occurs between altitudes of 73 450 and 1500 m (Dvorak et al., 1989). 74 Site growth modeling has proved to be a practical and accurate method to predict the performance 75 of species and provenance in these experiments (Louw & Scholes, 2004). Decision support models 76 that couple site growth modeling to future climate predictions based on General Circulation Models 77 (GCMs) can be a useful tool for forest managers to choose which provenances and species to plant 78 today in order to yield optimal growth during the rotations in the following decades. 79 This study aims to contribute to the development of management plans to adapt existing planted 80 forests in Colombia, Brazil and South Africa to the expected climate changes in the next decades. It is 81 hypothesized that in several areas, species and provenance choice of seed material has to be 82 changed in order to sustain the productivity of these planted forests in the next decades. The 83 objective of this study is to develop a decision support model that 1) predicts the impact of climate 84 change on wood productivity for new rotation cycles that have an expected harvest time around 85 2025 and 2) identifies the most suitable variety and ecotype of respectively P. patula and P. 86 tecunumanii to optimize wood productivity in the time period of these new rotation cycles. 87 5 88 Material and Methods 89 90 To develop the decision support model we drew on eight‐year old P. patula and P. tecunumanii 91 height growth data from a database of 153 provenances trials that were established by CAMCORE 92 members in Colombia, Brazil and South‐Africa during 1981 and 1997 (Dvorak & Donahue, 1995; 93 Dvorak et al. 2001). For each of the two P. patula varieties, P. patula var. patula and P.