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LIFE ZONES CLASSIFICATION SYSTEM OF HOLDRIDGEThe concept of life zones was developed by Clinton Hart Merriam in 1889. A life zone is characterized as an enviroment where the plant and animal life share unique and similar characteristics. The concept of life zones in Costa Rica has been applied to land development and conservation, as it has been in many places. The life zones were supposed to help determine land-use options and identify ecosystems. Merriam broke life zones down into these categories:
This system was eventually criticised for being too imprecise and Leslie Holdridge revised the concept of life zones to create what is known as Holdridge's Life Zones. Holdridge's sysem (1978) is a more complex classification system which is predominately based on three factors:
The biotemperature has essentially been mimicked from climatic zones of the earth, corrected by elevation climate classes on the location. Each of these factors are direct or indirect climatic factors, which must be obtained from climatic data.
Holdridge’s system (1978) consist of a triangle of honeycomb shaped cells, each with varying climatic and precipitation characteristics.
Direct and indirect climatic modifiers as the prime modifiers has severe limitations for mapping purposes. First of all, Vreugdenhil et al (2002) have argued that available climate maps are extremely coarse and speculative, as in most developing countries, climatic data are based on sparsely distributed, poorly maintained weather stations. Areas with natural ecosystems often have limited access, and weather stations are usually absent. Secondly, Data recording is often unreliable, taken irregularly and sometimes even fraudulent, particularly in remote areas. Therefore climatic maps are of very limited use for distinguishing between different vegetation and ecosystem classes.
Worldwide climate zones are even less useful, as they are so coarse that they usually provide no more than 1 - 3 classes for medium sized countries and 1 for small countries. While a bit more detailed in mountain regions, in climatically homogeneous regions, like vast areas in Siberia and in the Amazone, the Holdridge Live Zone classification generates hardly any classes at all: One cell of the Holdridge System (tropical moist forest) encompasses a vast swath of Amazonian forest. Within this swath of territory are some 30,000 species of trees distributed among scores of distinct communities. Clearly the Holdridge System fails to represent this diversity even worse than any of the other classification systems. Another problem with the Holdredge system is that it can't be drawn from readily available data. It requires rather complex modeling from rather large data sets. While this is possible nowadays, it was not in the nineteen seventies and eighties. It is not surprising that the existing Holdridge maps have very few classes and are very small. Given the complexity of the requiered modeling, the absence of computer power and the unreliability and scarce distribution of weather station in those days, those maps must have been hand drawn sketches, primarily based on existing course elevation and poor quality precipitation maps. In other words, those maps are sketchy reflections of the system at best, and most likely mere fantasies.
The now broadly available GIS and remotely sensed imagery, allow multi-criteria classification and much higher levels of precision. For the design of protected areas systems, biounits distinguished by this classification system on existing maps are too unreliable and coarse to be used at all.
This page is part of our web-book on Biodiversity Conservation. For organized reading go to our on-line Table of Content, or download our book in pdf format. |
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NATURE WORLDWIDE is the official website of the World Institute for Conservation and Environment, WICE. It is an integrated network of web sites dealing with different topics on nature, nature conservation and natural resources management. Read here why we created Nature Worldwide. Our Methodology explains how we produced our information. Our Site Map helps you find your way in the website. We made this website out of passion for conservation. We spent our own salaries and free time to gather the information and publish it on these websites, in total valuing hundreds of thousands of dollars of professional time. Nobody pays us to do this. We simply want to contribute to conservation. If you appreciate our work, PLEASE visit our site Adopt A Ranger and see how you can make a difference for conservation most effectively: By paying one day of the salary of a ranger, you will make a difference in conserving the lives of thousands of birds, other critters and entire forests. Enjoy! NATURE DU MONDE est le site Web officiel du World Institute for Conservation and Environment, WICE, C'est une collection intégrée de sites web qui traitent avec des sujets différents sur nature, conservation de la nature et gestion des ressources naturelles. Lisez ici pourquoi nous avons créé Nature de Monde. Notre Methodologie explique comme nous avons produit nos renseignements. Notre Site Map vous aide trouver votre entrée dans le site web. Beaucoup de plaisir! NATURALEZA DEL MUNDO es la página Web oficial del World Institute for Conservation and Environment, WICE, Es una red de páginas Web tratando de temas diferentes relacionados a la naturaleza, la conservación el manejo de recursos naturales, parques nacionales y áreas protegidas. Lea aqui porqué hicimos Naturaleza del Mundo. Nuestra Methodología explica como produjimos la información. Nuestro Mapa del sitio le ayuda encontrar su información en nuestra página web. Disfrute! NATUREZA DO MUNDO é o Web site oficial do World Institute for Conservation and Environment, WICE, Es uma red de páginas Web tratando de temas diferentes relacionados à natureza, la conservação el manejo de recursos naturaleiss, parques nacionais y áreas protegidas. Lea aqui porqué creamos Natureza do Mundo. Nossa Methodología explica como produjimos a informação. Nosso Mapa do sitio le ayuda encontrar sua informação no web site. Desfrute! NATUR DER GANZEN WELT ist, die offiziellen Website der World Institute for Conservation and Environment, WICE. Es ist ein einheitliches Netzwerk von Web Sites, über Themen wie Natur, Natur-Schutz und natürlichem Ressourcen Quellen Hege. Lesen Sie hier warum wir Natur der ganzen Welt gemacht haben. Unsere Verfahrensweise erklärt, wie wir unsere Informationen produziert würde. Unsere Site Map hilft Ihnen Ihren Weg im Website zu finden. Viel Spaß! NATUUR UIT ALLE STREKEN is, de officiële Website van het World Institute for Conservation and Environment, WICE. Het is een geïntegreerd Netwerk van websites, over Natuur, Natuurbescherming en het beheer van natuurlijke hulpbronnen. Lesen Sie hier warum wir Natuur uit alle Streken gemacht haben. Onze pagina Methode legt uit, hoe we onze informatie vergaarden. Onze Site Map helpt u op weg door onze website. WICE is a worldwide non-government non-profit organization that contributes to the conservation of nature. While it works on a many issues related to the conservation of nature and the protection of the environment, it is particularly committed to the conservation of national parks and other protected areas. WICE - USA office: 1639 Steamboat Run Road Shepherdstown, WV25443, USA
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