DOI: 10.5061/dryad.000000064
title: Remote sensing and field information aid in predicting the presence of the terrestrial orchid Cyclopogon lute-albus

description: Tropical montane cloud forest is one of the most threatened ecosystems, in
 central Veracruz, Mexico. Within this ecosystem, terrestrial orchids are
 strongly dependent on forest conditions and may be sensitive to
 environmental change. We applied field surveys of abiotic and biotic
 factors associated with the presence of the terrestrial orchid Cyclopogon
 luteo-albus and combined this with correlative niche modeling approaches
 to evaluate its potential distribution under two different environmental
 sets and two different extents. Layers of environmental information were
 obtained from Landsat imagery and interpolated bioclimatic and soil
 property layers. Existing species records were used as training data by
 sampling five forest fragments in central Veracruz, utilizing herbarium
 and global biodiversity information facility databases. The resulting
 predictions were tested by sampling at 15 sites of potential distribution.
 The model predicted the presence of C. luteo-albus with a reliability of
 80%. The most important variables of models derived from interpolated
 layers coincide with site-relevant parameters suggesting the utility of
 these tools to further explore species suitabilities at larger geographic
 extents. Potential distribution mapping is an important tool to identify
 key areas for conservation and priority areas for future studies of
 species and partially resolves the lack of records of many orchid species.
description: To obtain vouchered records of terrestrial orchids collected in
 central Veracruz, the database of the XAL Herbarium (Instituto de
 Ecología, A.C. at Xalapa, Veracruz, Mexico) was consulted. Species records
 that were correctly georeferenced within the altitudinal range and
 collected in TMCF in the region of the municipalities of
 Banderilla-Xalapa-Coatepec were selected, resulting in 15 locations for
 <em>C. luteo-albus</em>. Due to the limited number of
 collections in the herbarium, we also downloaded presence data from the
 public databases global biodiversity information facility (GBIF) and
 Instituto de Biología (UNAM). This search resulted in 25 additional unique
 observational records. These records were used to generate a model of the
 environmental suitability of <em>C. luteo-albus</em> across
 two regions of interest, one close to the area of central Veracruz where
 field surveys were also carried out and another for the entire extent of
 occurrence for the species in Mexico. Spatial analysis was performed in
 ArcView ver. 3.2 (ESRI, Redlands, CA) After review of
 the XAL herbarium and observational records, five TMCF fragments were
 identified in which <em>C. luteo-albus</em> has been
 previously collected. We visited each of these sites (all sites were
 visited within the same week) to register richness and abundance of
 <em>C. luteo-albus</em>, following the method of Peet et al.
 (1998). Sampling in the study sites was timed to correspond with the
 flowering peak (June–September). To assess possible effects of site
 conditions on the presence of <em>C. luteo-albus</em>, a suite
 of site-level variables was assessed in each of five randomly distributed
 plots (10 × 10 m), starting with percentage of canopy openness (measured
 with a convex spherical densiometer, Forestry Suppliers, Inc. ®), weed
 cover (%), diameter at breast height (DBH) of trees &gt; 5 cm
 (diameter measuring tape, Forestry Suppliers, Inc. ®).
description: Microsoft Excel