Applying Biogeographic Principles to Resource Management: a Case Study Evaluating Holdridge's Life Zone Model
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Great Basin Naturalist Memoirs Volume 2 Intermountain Biogeography: A Symposium Article 16 3-1-1978 Applying biogeographic principles to resource management: a case study evaluating Holdridge's Life Zone model James A. MacMahon Department of Biology and Ecology Center, Utah State University, Logan, Utah 84322 Thomas F. Wieboldt Department of Biology and Ecology Center, Utah State University, Logan, Utah 84322 Follow this and additional works at: https://scholarsarchive.byu.edu/gbnm Recommended Citation MacMahon, James A. and Wieboldt, Thomas F. (1978) "Applying biogeographic principles to resource management: a case study evaluating Holdridge's Life Zone model," Great Basin Naturalist Memoirs: Vol. 2 , Article 16. Available at: https://scholarsarchive.byu.edu/gbnm/vol2/iss1/16 This Article is brought to you for free and open access by the Western North American Naturalist Publications at BYU ScholarsArchive. It has been accepted for inclusion in Great Basin Naturalist Memoirs by an authorized editor of BYU ScholarsArchive. For more information, please contact [email protected], [email protected]. APPLYING BIOGEOGRAPHIC PRINCIPLES TO RESOURCE MANAGEMENT: A CASE STUDY EVALUATING HOLDRIDGE'S LIFE ZONE MODEL 1 1 2 James A. MacMahon and Thomas F. Wieboldt - Abstract.— Conservation schemes require some portioning of the world into a discrete number of subunits which might benefit from similar management practices. The Holdridge Life Zone scheme, proposed for such purposes previously, is applied to Utah as an initial test of its usefulness. A hypothetical life zone map was devel- oped entirely on the basis of weather station data and data derived from these values. This predictive map com- pared favorably to data on patterns of vegetation, mammal, reptile, and amphibian distribution in Utah. Since the publication of MacArthur and (1977a) suggested a series of concrete steps Wilson's (1967) analytical approach to the one might opt to test the various hypoth- biogeography of islands, several authors eses. It was hoped that this would be appli- have attempted to apply island bio- cable on a world scale. geography theory to the problem of opti- In summary the suggestion was to deter- mum size and number of nature reserves. mine the most sensitive species to be pre- Several aspects of theory have been in- served (i.e., rarest, largest, highest trophic- voked including species/ island area relations level, most vagile, etc.). This species deter- (Diamond 1975, Sullivan and Shaffer 1975, mines the minimum size of the reserve area. Wilson and Willis 1975) and extinction rates One might also, for a community, use the (Terborgh 1974). Not all workers agree that species area relationship (MacArthur and this approach is correct or robust (Sim- Wilson 1967). That relationship is berloff and Abele 1976). [See also rebuttals S = CA Z to Simberloff and Abele, e.g., Diamond where S = number of species, A = island (1976)]. Simultaneously the theories of is- area, C = parameter characteristic of a land biogeography are being changed or re- ticular taxon and archipelago and z = pow- stated in verifiable formats (Simberloff er derived by assuming species abundances 1976). are distributed in a log normal manner Currently economics (Myers 1976) and (Preston 1962). The value of C is a commu- even international cooperation (Franklin nity coefficient and not known for most 1977) are being included as factors jn na- communities. One must also invoke consid- ture reserve establishment. Despite all of eration of extinction rates for determining the interest in the application of theory to the number of replicate areas necessary practical problems there are few attempts (Terborgh 1974). to provide a reasonable plan to test the effi- MacMahon pointed out that if the total cacy and appropriateness of the implied world variety of communities was reduced theory /practice merger. into some small grouping to determine Recently, without judging whether or not functions like C and determine whether or theory was adequate or correct, MacMahon not there is similar value of C for most ex- 'Department of Biology and Ecology Center, Utah State University, Logan, Utah 84322. 'WieDoldt reduced some data for this paper. He did not prepare the manuscript and should be held accountable for the content. 245 246 GREAT BASIN NATURALIST MEMOIRS No. 2 amples of communities within one of these titudinal belt, the latitudinal region alone is groups, then the conservation process could used with the humidity province. An ex- proceed more rapidly and be applied more ample will illustrate this procedure. Logan, broadly. Utah, lies at an elevation of 4,790 ft (1460 The suggestion was made that a possible m), has a mean annual biotemperature of system of classification, often used but sel- 10.0 C and a mean total annual precipi- dom tested, was that of Holdridge (1947, tation of 16.64 inches (423 mm). Using the 1967). Holdridge's scheme uses mean annual standard lapse rate of 6 C per thousand me- biotemperature (the sum of mean monthly ters, a mean annual sea level biotempera- temperature above C divided by 12), ture of 18.76 C is calculated corresponding mean annual precipitation and potential to the subtropical latitudinal region (Fig. 2). evapotranspiration to place localities on a The actual biotemperature of 10.0 C corre- chart divided into hexagons representing sponds to the montane altitudinal belt (Fig. vegetation types (Fig. 1). Corrections are 2). The lines for a 10.0 C biotemperature made for altitudinal differences at similar and 423 millimeters precipitation intersect latitudes (Holdridge 1967, Sawyer and Lind- within the steppe life zone (Fig. 1). The tri- say 1963, Tosi 1964) (Fig. 2). nomial life zone designation of Logan, The hexagonal areas are termed life Utah, would be subtropical montane steppe. zones. When a specific site is located on The question is, do all communities of the the Holdridge model, a trinomial designa- world falling into a particular life zone, tion corresponding to its latitudinal position, e.g., subtropical montane steppe, have sim- altitudinal belt, and humidity province is ilar values of C and can they be treated in applied. If the station lies in the basal al- the conservation sense in a similar way? ALTITUDINAL BELTS LAT ITUDINAL REGIONS :'. -* POLAR £ \ i a i \ \ 64 00 32 00 \ \ \ \ SEMIPARCHED SUPERARID PERARID PERHUMID SUPERHUMID HUMIDITY PROVINCES (after Fig. 1. Graphical model to assign life zone designations to localities based on three abiotic measurements Holdridge 1967). 1978 INTERMOUNTAIN BIOGEOGRAPHY: A SYMPOSIUM 247 Note that we are aware that the evolution (see review Holdridge et al. 1971) suggest of species, major taxa differences, and the its plausibility for vegetation (Lindsey and specific species-species interactions in the Sawyer 1970, Sawyer and Lindsey 1963, various examples of particular life zones 1971, Thompson 1966), tropical birds (Slud will all dictate detailed differences from 1960, 1976), and tropical reptiles and am- place to place. Despite this, the question re- phibians (Heyer 1967), a more detailed mains—is there a least common denominator faunal and vegetational test seems appropri- of similarity such that not every community ate. We report here on an attempt to an- in the world will have to be studied before swer the question whether life zones pre- it can be conserved? If ecological laws dicted on Holdridge's model do coincide really exist this least common denominator with the patterns of distribution of animals should be identifiable at some level of reso- and plants in nature to a significant degree. lution, albeit generalized. The first step in answering the specific Methods question at hand is to ascertain whether or not the Holdridge model is applicable si- Data from 68 weather stations, selected multaneously to plants and animals (commu- from throughout Utah and having long cli- nities), outside of the tropics and in an area matic records (i.e., a minimum of 30 year where sufficient climatic and distribution averages of monthly temperatures and an- data are available. nual precipitation based on 1931-1960 Since the few tests of the Holdridge mod- records) were the main data base to gener- el by people outside the Holdridge group ate the "theoretical life zones" of Utah. Re- BASAL BELT POSITION 0" 1.5" 3 L A^O LAr|_ _BOR EAL_ _COO L TEMPE R_ATU R E_ _WA RM_T E MP ERAJ U R E SUB T R OjMCAL TR ICAL fO I _ _[ _ j_ _ _ _ °f u LATITUDINAL REGIONS (MEAN ANNUAL BIOTEMPERATURE AT SEA LEVEL. O) Fig. 2. Approximate guideline positions of latitudinal and altitudinal corrections to the Holdridge life zone sys- tem. Data based on an average adiabatic lapse rate of 6°C/1000 m (after Holdridge 1967). 248 GREAT BASIN NATURALIST MEMOIRS No. 2 cords of longer duration are available for Records of shorter duration are used wher- certain stations. In these cases averages ever climatological data gaps occurred in based on the total vears of record are used. critical geographic areas. Subtropical Lower ["""I Subtropical Montane Warm Temperate Montane Montane Desert Scrub Dry Scrub Moist Forest Subtropical Lower Subtropical Montane Warm Temperate Montane Montane Steppe Steppe Wet Forest Subtropical Montane Subtropical Montane Warm Temperate Subalpine Desert Moist Forest Moist Forest F!^1 Subtropical Montane Subtropical Montane Warm Temperate Subalpine Li^J Desert Scrub Wet Forest Wet Forest Fig. 3. Predicted potential life zone map of Utah. Assignment of localities to Holdridge life zones derived en- tirely from abiotic data based on United States Weather Bureau data corrected as described in the text. 1978 INTERMOUNTAIN BIOGEOGRAPHY: A SYMPOSIUM 249 precipitation Temperature and data pro- drawn (Fig. 8) based on data in Stebbins vide only a rough approximation of the life (1966). These two groups of vertebrates zones because of topographic and phys- were used because they represent taxa of iognomic complexity. Maps of available relatively high habitat fidelity, relatively evapotranspiration, heat, potential and nor- low vagility (compared to birds), and well- mal annual precipitation from Jeppson et al.