DOI: 10.5061/dryad.tqjq2bw23
title: Highly-replicated soil, topography and vegetation sampling across an old-growth tropical rain forest landscape

description: Here we present data from highly-replicated sampling of soil, topography,
 and vegetation across an old-growth tropical rainforest landscape at the
 La Selva Biological Station, Costa Rica.  Samples were taken at
 100 x 50 m spacing using an existing surveyed grid system.  The
 573-ha sample area spanned a variety of soil, topographic and vegetation
 conditions, including flat terraces on old alluvial soil, ridge tops and
 steep slopes on residual soil, riparian habitats and fresh-water
 swamps.  At each of 1170 grid points we established a circular
 0.01 ha quadrat (radius = 5.64 m).  We sampled soil at 30-50 cm
 depth with a soil augur and collected a sample for subsequent
 analysis.  We measured slope angle with a clinometer and slope
 direction with a compass.  We measured stem diameter to +1 mm
 with a synthetic fabric diameter tape for all stems &gt;10 cm diameter
 (N= 5236) at 1.3 m from the ground or to ~ 6 m height if there were basal
 irregularities.  We classified stems to life form (tree, palm,
 liana), and identified all trees and palms to species or morphospecies
 (N=266; lianas were not identified to species).  We collected
 vouchers from all trees that we could not positively identify in the field
 (N=920). As a whole the data set presents an integrated view of soil,
 topography and vegetation across a mesoscale old-growth tropical rain
 forest landscape.  The data have been used to refine a
 reserve-wide soils map for La Selva, and for a variety of papers analyzing
 the interactions of soil, topography and species distributions at
 landscape scales (see the 10 papers listed in the Related Works section
 below). There are no restrictions at all on the use of these data, and we
 think they will be useful for teaching and analysis projects as well as
 further original research applications.  The data also provide a
 detailed benchmark of the status of old-growth vegetation in 1993-95 for
 one of the most intensively studied tropical rain forest landscapes in the
 world.  Because the data are accurately georeferenced and
 detailed metadata on all methods are provided, this study could be
 repeated at any time to assess the trajectory of vegetation changes at La
 Selva, particularly in relation to local disturbances and changing
 regional and global climates.   
description: Here we document the methods used for
 the soil and topography sampling, measurements of stem diameters for all
 individuals, and for identification of the tree and palm
 species. Soil samples were
 taken at 30-50 cm depth and a sample retained for further analysis.  Slope
 angle in the direction of water runoff was measured with a Suunto
 clinometer <sub>­</sub>+ 1 degree and slope
 azimuth in the same direction was measured with a Suunto compass
 + 1 degree.  See details in the file
 <strong>Vegetation map protocols original with Eng
 trans.pdf</strong>.  Development of the revised La Selva soils maps
 from the soil samples is described in detail on pg. 102-104 in Clark,
 D.B., D.A. Clark and J.M. Read (1998, Journal of Ecology 86:101-112), and
 on pg. 25 Clark D.A. (1998, Annals of the Missouri Botanical Garden
 85:18-33).  Detailed descriptions of how the larger soil units were
 analyzed based on these samples is given in <strong>Clark soil
 mapping units description.pdf</strong>. Methods for establishing each 0.01 ha plot
 and measuring stem diameters are given in <strong>Vegetation map
 protocols original with Eng trans.pdf.</strong> Most trees and palms species were
 identified in the field, mostly by the paraforesters Leonel Campos Otoya
 and William Miranda Conejo, with minor contributions from David B. Clark
 and Deboarh A. Clark.  For species that could not be positively identified
 in the field we collected voucher specimens (N= 920).  Voucher numbers are
 listed in the individuals table
 <strong>LaSelvaIndividualsTable.csv</strong>.  The
 identification of each voucher is documented in <strong>La Selva
 vegetation map vouchers list.pdf.  </strong>The original field work
 was completed in 1995.  Since that time there have been extensive changes
 in the taxonomy of tropical plants in general and of the family, genus and
 species names for La Selva species in particular.  The updated through
 2022 family, genus and species names for the taxa sampled here are given
 in <strong>Species names Vegetation Map 2022.csv</strong>. 
 The variable Genus_Species_95 can be used to link the 1995 names in
 <strong>LaSelvaIndividualsTable.csv </strong>to the same taxon
 in <strong>Species names Vegetation Map
 2022.csv</strong>. Data from the original field sheets
 (<strong>La Selva vegetation map scanned field
 sheets.pdf</strong>) were entered into two files and checked by
 readback.  The individual stems data (location, identifications, stem
 diameters) were entered into
 <strong>LaSelvaIndividualsTable.csv,</strong> and the soil and
 topographic data for each sample were entered into
 <strong>LaSelvaQuadratsData.csv</strong>.  The data have not
 been further processed in these files.
description: The data and metadata are in csv txt files and pdf files, and
 require no special software to open and fully use.