Mapping plant species ranges in the Hawaiian Islands: developing a methodology and associated GIS layers

Abstract

This report documents a methodology for projecting the geographic ranges of plant species in the Hawaiian Islands. The methodology consists primarily of the creation of several geographic information system (GIS) data layers depicting attributes related to the geographic ranges of plant species. The most important spatial-data layer generated here is an objectively defined classification of climate as it pertains to the distribution of plant species. By examining previous zonal-vegetation classifications in light of spatially detailed climate data, broad zones of climate relevant to contemporary concepts of vegetation in the Hawaiian Islands can be explicitly defined. Other spatial-data layers presented here include the following: substrate age, as large areas of the island of Hawaiÿi, in particular, are covered by very young lava flows inimical to the growth of many plant species; biogeographic regions of the larger islands that are composites of multiple volcanoes, as many of their species are restricted to a given topographically isolated mountain or a specified group of them; and human impact, which can reduce the range of many species relative to where they formerly were found. Other factors influencing the geographic ranges of species that are discussed here but not developed further, owing to limitations in rendering them spatially, include topography, soils, and disturbance. A method is described for analyzing these layers in a GIS, in conjunction with a database of species distributions, to project the ranges of plant species, which include both the potential range prior to human disturbance and the projected present range. Examples of range maps for several species are given as case studies that demonstrate different spatial characteristics of range. Several potential applications of species-range maps are discussed, including facilitating field surveys, informing restoration efforts, studying range size and rarity, studying biodiversity, managing invasive species, and planning of conservation efforts.

Applying landscape genomic tools to forest management and restoration of Hawaiian koa (Acacia koa) in a changing environment

“…For projecting GF results, we first used the GF predict function to predict genetic variation across all grid cells on the island of Hawaii. We then mapped the resulting predictions across the landscape masked by the expected distribution of A. koa / A. koaia (J.P. Price et al., ) using principal components of the predictions to generate a red–green–blue color scale according to the first three axes. Genetic offset under the future climate scenario was then estimated by first using the GF predict function with the future climate data and then estimating Euclidean distance between current predictions and future predictions weighted by variable importance for each grid cell on the landscape.…”

Occupancy and habitat use of the endangered Akikiki and Akekee on Kauai Island, Hawaii

“…116 Priority I areas are within the "Very wet," and Moderately wet" zones. Priority II areas include "Moist mesic" and "Seasonally mesic" zones.…”

Unexpected hydrogen isotope variation in oceanic pelagic seabirds

“…those two colonies are located above the cloud layer in the same dry subalpine moisture zone, where evapotranspiration is high even inside burrows (Whittow et al 1984;simons 1985;ainley et al 1997;hu et al 2001;Price et al 2007). In contrast, petrel breeding colonies on Kauai are primarily in the wettest zones of the archipelago, within the montane cloud belt where evapotranspiration is low (ainley et al 1997;simons and hodges 1998;Price et al 2007). Despite the large differences in expected evaporative water loss between Maui and Kauai hatch-year petrels, their mean δD values are very similar (Fig.…”