Marked tree demographic variation along subtle elevation differences partially explains species' habitat associations in an Amazonian forest

It is widely recognized that large-scale topographic variation affects the distribution of tree diversity, yet the effects of topography at smaller scales are less appreciated but can be no less consequential. We evaluated how small-scale topographic variation affects tree demography and diversity in a hyperdiverse Amazonian forest where species distributions respond strongly to elevation differences as small as 22 meters. For topographically structured species distributions to arise, species should grow and survive (perform) better in the topographic habitat they are associated with (best-at-home hypothesis), and they should outperform other species that are found, but not strongly aggregated, on that habitat (resident-advantage hypothesis). Here, we tested these demographic hypotheses using data on the growth and mortality of 79,911 trees (352 species) among three topographic habitats (valleys, slopes, and ridges) in the 25-ha Amacayacu Forest Dynamics Plot. Despite the small variatio..., Study areaThe dataset originates from the Amacayacu Forest Dynamics Plot (AFDP), a 25-hectare tropical wet forest plot in the Northwestern Amazon (3°48ʹS, 70°16ʹW). The AFDP, part of the Forest Global Earth Observatory (ForestGEO), features a unimodal rainfall regime (~3,216 mm/year), high humidity (86%), and a mean annual temperature of 25.8 °C. The plot encompasses diverse topographic habitats including ridges, slopes, and valleys, with generally poor, acidic soils dominated by kaolinite and quartz minerals.
Forest censusesTwo full censuses were conducted: the first from August 2007 to April 2009, and the second from August 2014 to November 2015. All woody plants ≥10 mm diameter at breast height (DBH; 1.3 m) were mapped, tagged, measured, and identified taxonomically, with vouchers deposited at the Herbario Amazónico Colombiano (COAH).
Topographic Habitat ClassificationThree topographic habitats—ridges, slopes, and valleys—were defined using hierarchical clustering based on elevation,..., # Marked tree demographic variation along subtle elevation differences partially explains species' habitat associations in an Amazonian forest

Dataset DOI: [10.5061/dryad.b2rbnzst1](10.5061/dryad.b2rbnzst1)

## Description of the data and file structure

The data consists of two databases: one for mortality (`m.csv`) and another for growth (`g.csv`). The mortality database is at the tree level (one row per tree), whereas the growth database is at the stem level (one row per stem, with multiple rows per tree in the case of multi-stemmed trees).

### Files and variables

#### File: g.csv

**Description:** 

##### Variables

* tag: Individual tree tag
* stemtag: Stem identifier. Note that a tree can have multiple stems.
* Species: Species code used to identify unique species names.
* dbh: Diameter at breast height (1.30 m) of the stem at time 1, measured in millimeters.
* G: Estimated growth rate in millimeters. G was estimated as (dbh*2 - dbh*1)/(time_*diff) where dbh1 and dbh2 correspon...,