Stratification of Tropical Forests as Seen in Leaf Structure

The studies presented in this volume are meant to The reason why we know relatively little about close some gaps in our knowledge of leaf anatomy inner leaf structure of trees from tropical humid of trees in tropical humid forests. Although xero­ forests is that the leaf anatomy of only a few species morphy of the foliage in tropical humid forests has or genera or - at the most - of an entire family has been much discussed, the statements have generally been studied in detail up to the present. Most of been based on sporadic anatomical studies of part i­ these studies are, therefore, of taxonomic interest. cular species or genera, a complete area of the size They cannot be included in this study because they of 155. 5 ha has certainly never been considered. do not supply the same information or amount of The present studies analyse an entire inventory of a data presented here. Anatomical studies are very time consuiming because the material first has to be given region in which the number of species and the number of individuals is very well known. This fact prepared and cut before observation can begin. In­ allows the elaboration of many ecological aspects, vestigation of about 50 characteristics in 230 species which was the main intention of the author.

1. Introduction.- 2. Source of the Material and Sample Collection.- 3. Preparation of Slides.- 4. General Observations.- Leaf morphology.- Drip tip - Pulvini - Leaf size - Leaf shape - Juvenile and adult leaf forms - Venation.- Innter leaf structure.- Xero-, meso-, hygromorphy, and sun-, medium-, shade-leaf, alternatively - Leaf consistency - Structural peculiarities.- Structure in relation to function.- 5. Tables of the Families Studied Indicating Structural Characteristics.- Annonaceae - Capparidaceae - Violaceae - Flacourtiaceae - Vochysiaceae - Guttiferae - Quiinaceae - Sterculiaceae - Tiliaceae - Elaeocarpaceae - Humiriaceae - Malpighiaceae - Rutaceae - Simaroubaceae - Ochnaceae - Burseraceae - Meliaceae - Dichapetalaceae - Olacaceae - Opiliaceae - Celastraceae - Sapindaceae - Sabiaceae - Anacardiaceae - Mimosaceae - Caesalpiniaceae -Papilionaceae - Rosaceae - Combretaceae - Myrtaceae - Lecythidaceae - Melastomaceae - Araliaceae - Rubiaceae - Sapotaceae - Ebenaceae - Apocynaceae - Boraginaceae - Solanaceae - Bignoniaceae - Verbenaceae -.- Nyctaginaceae - Polygonaceae - Myristicaceae - Lauraceae - Euphorbiaceae - Moraceae - Lacistemaceae - Unidentified (Nigua).- 6. Description of the Families Studied Concerning Leaf Structure.- Annonaceae - Capparidaceae - Violaceae - Flacourtiaceae - Vochysiaceae - Guttiferae - Sterculiaceae - Tiliaceae - Elaeocarpaceae - Malpighiaceae - Rutaceae - Simaroubaceae - Ochnaceae - Burseraceae - Meliaceae - Dichapetalaceae - Opiliaceae - Celastraceae - Sapindaceae - Sabiaceae - Anacardiaceae - Mimosaceae - Caesalpiniaceae - Papilionaceae - Rosaceae - Combretaceae - Myrtaceae - Lecythidaceae - Melastomaceae - Rubiaceae - Sapotaceae - Ebenaceae - Apocynaceae - Boraginaceae - Solanaceae - Bignoniaceae - Verbenaceae - Nyctaginaceae - Polygonaceae - Myristicaceae - Lauraceae - Euphorbiaceae - Moraceae - Lacistemaceae.- 7. Developmental Aspects.- Development of crypts and “cornets” around the stomata - Formation of cork warts - Origin of the oblique position of palisade cells.- 8. Ecological Aspects.- Xeromorphy, succulence, and hygromorphy.- Criteria of xeromorphy - Criteria of hygromorphy.- Sun and shade leaf type.- Criteria of the sun leaf type - Criteria of the shade leaf type.- The significance of the different structural features and their ecological importance.- Blade thickness - Number of layers of the upper epidermis - Waxy layers - Cuticle - Thickness of the outer wall of the upper epidermis - Cell size of the upper epidermis, as seen in transection - Cell size and form of the upper and lower epidermis, as seen in surface view - Number of palisade layers - Length of palisade cells - Length/width index of the palisade cells - Index palisade parenchyma/spongy parenchyma - Stomate density - Stomata length - Level of stoma formation - Hair density - Papillas, wall excrescences and surface sculpturing - Density of vascular bundles - Secretory cells - Secretory canals or cavities - Upper and lower hypodermis - Sclereids - Glands - Slimy walls - Stomata in the upper epidermis - Upper epidermis as a water reservoir - Xero-, meso-, hygromorphic leaves and sun and shade leaf type.- The progressive transformation of the hygromorphic shade leaf into the xeromorphic sun leaf.- Blade size and shape - Blade thickness - Width of outer wall of the upper epidermis - Upper epidermis as a water- storing tissue - Number of epidermis layers - Formation of a (upper or lower) hypodermis - Number of palisade layers - Length of paisade cells - Length/width index of the palisade cells - Chloroplasts - Proportions between palisade and spongy parenchyma - Stomata size and density - Level of stoma formation - Development of “cornets” and crypts - Hair density - Papillas, wall excrescences and surface sculpturing - Density of vascular bundles - Xero-, meso-, hygromorphic leaves - Sun and shade leaf type - The increasing width of the leathery leaf - Comparison of juvenile and adult leaves.- Comparison with the cloud forest - The leathery leaf - Environmental conditions.- Soil - Water supply - Illumination - Temperature.- 9. Taxonomical Aspects.- 10. Phylogenetic Aspects.- 11. Discussion of the Most Important Results.- 12. Figures to the Text.- 13. Bibliography.- 14. Index of Scientific Plant Names.- 15. Index of vernacular plant names.- 16. General Index.