A review of dipterocarps - Center for International Forestry Research

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Seed Physiology 58 Table 1.Optimum germination temperatures, germination rates and base temperature values (Tompsett and Kemp 1996a, b). Species Base temperature (°C) approach was adopted in a series of germination studies so that physiological parameters could be assessed (Table 1). Optimum germination for 30 species was confirmed as lying between 26°C and 31°C and the value for the time to 50% final germination, at the optimum temperature, generally ranged between 2 and 13 days. There were two Dipterocarpus species (D. alatus and D. costatus) that were much slower to germinate, however. A physiological parameter relating to the theoretical value at which zero growth occurs was also assessed; this is referred to as the ‘base temperature’. The base Time to 50% final germination at the optimum temperature (d) Optimum temperature (°C) Radicle length defining germination (mm) Shorea almon n/a n/a 26 5 Shorea siamensis n/a n/a 26 5 Shorea smithiana n/a n/a 26 3 Shorea pinanga n/a n/a 31 10 Hopea parviflora n/a 11 31 5 Shorea roxburghii n/a 11 31 5 Dipterocarpus alatus n/a 20 26 5 Shorea robusta n/a 4 31 5 Anisoptera marginata n/a 6 26 3 Hopea foxworthyi 6.4 4 31 3 Hopea odorata 7.1 2 31 5 Shorea leprosula 7.5 4 31 3 Shorea parvifolia 8.3 4 26 3 Shorea contorta 8.8 7 26 3 Shorea affinis 9.4 5 26 3 Parashorea smythiesii 9.7 3 31 3 Dipterocarpus costatus 10.2 30 31 3 Dryobalanops aromatica 10.5 3 26 3 Parashorea tomentella 10.5 9 31 10 Shorea guiso 11.0 4 26 3 Anisoptera costata 11.4 5 26 3 Shorea ferruginea 12.2 6 26 3 Dipterocarpus obtusifolius 12.4 3 26 5 Cotylelobium burckii 13.0 9 26 3 Vatica mangachapoi 13.0 9 31 3 Dipterocarpus turbinatus 15.2 5 26 10 Cotylelobium melanoxylon 15.4 6 31 3 Dipterocarpus tuberculatus 15.8 13 31 5 Shorea amplexicaulis 15.8 7 26 3 Dipterocarpus zeylanicus 16.2 11 26 10 Shorea argentifolia 16.4 4 26 3 temperature is the intersect on the temperature axis for the plot of germination rate against temperature. More details of technique are given in Tompsett and Kemp (1996a, b); the parameter is further discussed below. Chilling damage Studies show germination is reduced or does not occur at temperatures below 16°C for several dipterocarp species (Tompsett 1985, Corbineau and Come 1986), due to chilling damage. This type of damage is also observed in the results from storage research; data show a reduced ability to survive low temperature conditions
Seed Physiology 59 (Sasaki 1980, Yap 1981, Tompsett 1985, Corbineau and Come 1986). Sasaki (1980) considered seeds of (i) Shorea species in the ‘yellow and white meranti’ groups, (ii) Hopea, (iii) Dipterocarpus, (iv) Vatica, (v) Dryobalanops, (vi) Balanocarpus and (vii) Parashorea to be tolerant down to 4°C. By contrast, he believed that seeds of Shorea species in the ‘red meranti and balau’ groups were intolerant of temperatures below 15°C. He classified Anisoptera as a tolerant genus in a separate publication (Sasaki 1979). Yap (1981) later proposed a three-group classification: firstly, seed of species in the Dipterocarpus, Dryobalanops, Neobalanocarpus and Vatica genera were said to be intolerant of temperatures below 14°C; secondly, seed of Shorea species in the sections Mutica, Pachycarpae and Brachypterae were considered intolerant of temperatures below 22°-28°C; and, finally, seed of Shorea species in the Anthoshorea section and seed of Hopea and Parashorea could be cooled to 4°C (but were recommended to be stored at 14°C). Further details relating taxonomic classification to chilling damage are given elsewhere (Tompsett 1992). A possible explanation for the above inconsistencies is that different authors have studied the effects of chilling for different periods of time, leading to different conclusions; exposure of seed to longer periods of chilling can show up chilling damage which might otherwise have ben missed in the case of relatively chillresistant species. The processes behind the chilling physiology phenomenon have not been adequately studied. However, differences among species in susceptibility to chilling damage are confirmed by the base temperature data in Table 1. In particular, Hopea species appear the most resistant to chilling damage, since they have the lowest base temperatures. A low value for the base temperature is expected if germination ability decreases relatively slowly as germination temperature is reduced. It should be emphasised, however, that these results apply exclusively to moist seeds. Storage of dry orthodox dipterocarp seeds at low temperatures is described in the storage section below. The differences in chilling tolerance of seeds among dipterocarp species are quantitative rather than qualitative. Seed of the ‘tolerant’ species S. roxburghii eventually suffers damage at 2°C -5°C relative to seed kept at warmer temperatures (Purohit et al. 1982, Tompsett 1985). Another example of chilling damage which occurred over a lengthy period of time is that to H. hainanensis. For this species, seed at 5°C almost all died after 6 months; by contrast, at 15°C -20 °C no loss of viability occurred (Song et al. 1984). Harvest and Maturity The condition of seed at harvest is of primary concern in the planning of all physiological experiments. Moisture contents at or near harvest are given for 25 species in Table 2, including examples from both seasonal and aseasonal dipterocarp forests. Seeds of the three species with the lowest moisture contents, which are found in seasonal forests, were collected from the ground after natural desiccation. For these seeds, drying occurs very swiftly after abscission because the open canopy exposes them to direct sunlight. Of the remaining species listed, some are derived from the dry forest and others from moist areas; they possessed a relatively high range of post-processing moisture contents between 29 and 56% (usually, seeds were just de-winged). It has been realised for some time that there can be a considerable difference between whole-seed moisture content and moisture content of the embryo or embryo axis (Grout et al.,1983). Since axis or embryo moisture content is more closely related to basic physiological processes than whole seed moisture content, it is a preferable measure to use herein. Axis values have been determined for dipterocarp species (Table 2) and range from 51 to 74%, except in the case of the much lower value for the dry-zone species Dipterocarpus tuberculatus, which was collected after natural drying. Seed maturation A few developmental studies have been carried out on dipterocarp species; whole-seed moisture content has been employed in most of these as the main physiological criterion. Sasaki (1980) reported that the moisture content (wet basis) of Shorea roxburghii declined from 60 to 50% in the final 3 weeks of maturation on the tree. Panochit et al. (1986) reported a comparable decline from 40 to 30% for the same species, whilst a reduction from 59 to 49% was reported for S. siamensis (Panochit et al. 1984). Nautiyal and Purohit (1985a) assessed changes during maturation of S. robusta seed; they described these changes as biphasic. Over the 60 days from anthesis to maturity, concentrations of soluble carbohydrates, starch, soluble protein and acid phosphatase were
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A Review of Dipterocarps Taxonomy,
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ã 1998 by Center for International
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Authors S. Appanah Forest Research
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SPINs Species Improvement Network T
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Foreword The Center for Internation
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Introduction As a consequence, much
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Introduction each project that is m
Page 15 and 16: Biogeography and Evolutionary Syste
Page 55 and 56: Conservation of Genetic Resources i
Page 65: Seed Physiology P.B. Tompsett Seed
Page 69 and 70: Seed Physiology 61 § orthodox; and
Page 71 and 72: Seed Physiology 63 Table 4. Lowest-
Page 73 and 74: Seed Physiology 65 Table 5. (contin
Page 75 and 76: Seed Physiology 67 Table 6. Viabili
Page 77 and 78: Seed Physiology 69 Dipterocarp seed
Page 79 and 80: Seed Physiology 71 Roberts, E.H. 19
Page 81 and 82: Seed Handling 74 viability of the s
Page 83 and 84: Seed Handling 76 the basic activiti
Page 85 and 86: Seed Handling 78 Table 2. Seed (fru
Page 87 and 88: Seed Handling 80 Table 3. Mean inse
Page 89 and 90: Seed Handling 82 Seedling storage u
Page 91 and 92: Seed Handling 84 air will ensure ra
Page 93 and 94: Seed Handling 86 ASEAN Forest Tree
Page 95 and 96: Seed Handling 88 Tompsett, P.B. and
Page 97 and 98: Seedling Ecology of Mixed-Dipteroca
Page 107 and 108: Root Symbiosis and Nutrition Table
Page 109 and 110: Root Symbiosis and Nutrition Table
Page 111 and 112: Root Symbiosis and Nutrition specie
Page 113 and 114: Root Symbiosis and Nutrition in Sab
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Root Symbiosis and Nutrition 5. Lim
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Root Symbiosis and Nutrition Group
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Root Symbiosis and Nutrition Takaha
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Pests and Diseases of Dipterocarpac
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Management of Natural Forests S. Ap
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Management of Natural Forests about
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Management of Natural Forests 4. Cl
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Management of Natural Forests were
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Management of Natural Forests incre
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Management of Natural Forests 1. He
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Management of Natural Forests which
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Management of Natural Forests Cheng
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Management of Natural Forests Uebel
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Plantations 152 macrocarpa, V. indi
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Plantations 154 are: Dipterocarpus
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Plantations 156 and no longer in ne
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Plantations 158 able to store them
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Plantations 160 ‘Predictive Test
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Plantations 162 Qureshi et al. (196
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Plantations 164 Tomboc and Basada (
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Plantations 166 are removed. Anothe
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Plantations 168 intervention. Sange
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Plantations 170 mono-layered. The r
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Plantations 172 diameter of 46.3 m
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Plantations 174 Ang, L.H., Maruyama
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Plantations 176 Cheah, L.C. 1971. A
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Plantations 178 Kadambi, K. 1957. B
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Plantations 180 Moura-Costa, P. 199
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Plantations 182 Regional Workshop o
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Plantations 184 Conference on Dipte
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Non-Timber Forest Products from Dip
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Scientific Index BIXALES, 25 BOLETA
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Scientific Index EPHEMEROPTERA, 119
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Scientific Index Ovalis section, 8,
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Scientific Index Shorea leptoderma,
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Scientific Index VATERINAE sub-trib
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General Index barus kapur, 192-3 ba
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General Index endangered species, i
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General Index distribution, 15 enda
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General Index nurse crops, 161, 165
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General Index seed material, cryopr
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General Index TPI, 139 tractors, 15
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