Related Experiment Video
Updated: Aug 19, 2025
Development of an Individual-Tree Basal Area Increment Model using a Linear Mixed-Effects Approach
Published on: July 3, 2020
Exploring density- and frequency-dependent interactions experimentally: An r program for generating hexagonal fan
Carly Rozins1, Michael E Hood2, Jae Hoon Cho2
1Department of Integrative Biology, University of California, Berkeley, CA, USA.
Abstract:
Species interactions and diversity are strongly impacted by local processes, with both the density of a focal species and its frequency in the community having an impact on its growth, survival and fecundity. Yet, studies that attempt to control for variation in both frequency and density have traditionally required a large number of replicates.Hexagonal fan designs can include a range of both densities and frequencies in a single plot, providing large economies in space and material for studying local interactions such as competition and disease transmission. However, in practice such experiments can be difficult to plan and implement.This study presents an R program whereby the user can rapidly view a variety of designs and determine the configurations that work best with their space and material constraints. Simple instructions for implementing the fan in any design setting are also provided.We illustrate the implementation of a simple form of the hexagonal fan design in a field experiment to assess the impact of host density on pollinator movement and disease transmission.
More Related Videos
Related Concept Videos
02:46Crystal Field Theory - Tetrahedral and Square Planar Complexes
Crystal field theory (CFT) is applicable to molecules in geometries other than octahedral. In octahedral complexes, the lobes of the dx2−y2 and dz2 orbitals point directly at the ligands. For tetrahedral complexes, the d orbitals remain in place, but with only four ligands located between the axes. None of the orbitals points directly at the tetrahedral ligands. However, the dx2−y2 and dz2 orbitals (along the Cartesian axes) overlap with the ligands less than the dxy,...
01:21Frequency-dependent Selection
02:58Crystal Field Theory - Octahedral Complexes
To explain the observed behavior of transition metal complexes (such as colors), a model involving electrostatic interactions between the electrons from the ligands and the electrons in the unhybridized d orbitals of the central metal atom has been developed. This electrostatic model is crystal field theory (CFT). It helps to understand, interpret, and predict the colors, magnetic behavior, and some structures of coordination compounds of transition metals.
CFT focuses on...
02:33Lattice Centering and Coordination Number
Types of Unit Cells
Imagine taking a large number of identical...
03:02Colors and Magnetism
When atoms or molecules absorb light at the proper frequency, their electrons are excited to higher-energy orbitals. For many main group atoms and molecules, the absorbed photons are in the ultraviolet range of the electromagnetic spectrum, which cannot be detected by the human eye. For coordination compounds, the energy difference between the d orbitals often allows photons in the visible range to be absorbed and emitted, which is seen as colors by the human...
01:24Frequency-Domain Interpretation of PD Control
The proportional control gain, combined with the...