|Publication Type:||Journal Article|
|Year of Publication:||2006|
|Authors:||Hooghiemstra, H., Wijninga, V. M., Cleef A. M.|
|Journal:||Annals of the Missouri Botanical Garden|
|Keywords:|| Ecology: environmental biology - General and methods,  Ecology: environmental biology - Plant,  Coniferopsida,  Cyperaceae,  Palmae,  Xyridaceae,  Bombacaceae,  Euphorbiaceae,  Guttiferae,  Haloragaceae,  Loranthaceae,  Myricaceae,  Papaveraceae,  Polygalaceae,  Portulacaceae,  Ranunculaceae,  Staphyleaceae,  Thymelaeaceae,  Botany: general and systematic - Gymnospermae,  Botany: general and systematic - Monocotyledones,  Botany: general and systematic - Dicotyledones,  Botany: general and systematic - Floristics and distribution,  Paleobiology,  Geological periods - Tertiary, Alchornea: genus [Euphorbiaceae], Amanoa: genus [Euphorbiaceae], Angiospermae, biodiversity, Biogeography: Population Studies, Bocconia: genus [Papaveraceae], Bombacaceae: Angiosperms, Carex: genus [Cyperaceae], Ceiba: genus [Bombacaceae], climatic variation, Coniferopsida: Gymnosperms, Cyperaceae: Angiosperms, Daphnopsis: genus [Thymelaeaceae], Dicots, Dicotyledones, Environmental Sciences, Euphorbiaceae: Angiosperms, Gaiadendron: genus [Loranthaceae], Gunnera: genus [Haloragaceae], Guttiferae: Angiosperms, Gymnospermae, Haloragaceae: Angiosperms, Hypericum: genus [Guttiferae], Loranthaceae: Angiosperms, Mauritia: genus [Palmae], Monnina: genus [Polygalaceae], Monocots, Monocotyledones, montane forest, Montia: genus [Portulacaceae], Myrica: genus [Myricaceae], Myricaceae: Angiosperms, Nageia: genus [Coniferopsida], Paleobiology, Palmae: Angiosperms, Papaveraceae: Angiosperms, Plantae, Plants, Podocarpus magnifolius: species [Coniferopsida], Polygalaceae: Angiosperms, Portulacaceae: Angiosperms, Prumnopitys: genus [Coniferopsida], Ranunculaceae: Angiosperms, Ranunculus: genus [Ranunculaceae], Retrophyllum: genus [Coniferopsida], species distribution, Spermatophyta, Spermatophytes, Staphyleaceae: Angiosperms, Terrestrial Ecology: Ecology, Thymelaeaceae: Angiosperms, Turpinia: genus [Staphyleaceae], Vascular plants, Xyridaceae: Angiosperms, Xyris: genus [Xyridaceae]|
Plant microfossil and macrofossil associations obtained from six dated sections from the area of the basin of Bogota (2550 m, Eastern Cordillera, Colombia) show the evolution of the late Neogene Andean montane forest, triggered by the Andean orogeny. Progressive adaptation of warm tropical taxa to cool montane conditions, evolution of new nootropical montane taxa, and immigration of temperate Laurasian, Holarclic, and Austral-Antarctic elements gave shape to the present-day montane forest. Vegetational characteristics inferred from fossil plant associations reveal the altitude at the time of deposition. Neogene forests are floristically compared with contemporary forests at comparable altitudinal intervals in the surroundings of the Bogota basin; however, the absence of taxa that had not yet arrived, or evolved, is most salient and shows that non-analogue plant communities are common.The main phases of montane forest development are: (1) pre-uplift phase of the late Miocene with abundant lowland taxa with tropical or neotropical affinities (Mauritia Kunth, Amanoa Aubl., Ceiba Miller, and representatives of Humiriaceac); montane forest rich in Podocarpaceae (potentially including Nageia Gaertn., Podocarpus L'Her., Prumnopitys Phil., and Retrophyllum C. N. Page) covered other previously uplifted areas in the region; (2) toward the early Pliocene the area was uplifted to ca. 1000 m; the relative proportion of temperate taxa of North American and southern South American stock increased and occupied the slopes of the low mountains; and (3) by the middle Pliocene uplift had proceeded to ca. 2000-2200 m and tropical lowland taxa, which are now restricted to attitudes below 1000 m, are no longer recorded in the fossil plant associations; the increase in the number of newly appearing montane taxa (Myrica L., Turpinia Vent., Gunnera L., Bacconia L., Gaiadendron G. Don f., Dophnopsis C. Martins, and Monnina Ruiz & Pav.) suggests a significant increase of diversity.Until the late Pliocene there is little to no evidence for the existence of the paramo; taxa such as Xyris L., Hypericum L., Carex L., Montia L., and Ranunculus L. might have formed swamp or bog vegetation only. It is believed that these taxa colonized mountaintops with half-open vegetation; these areas extended when the mountains reached above upper forest line elevations.The distribution areas of the endemic genera of the Espeletiinae largely coincide with the youngest parts (< 5 Ma) of the northern Andes. Changing climatic conditions forced individual plant species to migrate vertically. Composition of plant communities changed continuously and vegetation belts frequently were altitudinally squeezed or offered possibilities for expansion. This long process stimulated speciation and provoked sequential non-analogue vegetation types. Thus, the biodiversity hotspot of the northern Andes has a dynamic history.