Biology subjects

Zawada, K. J.

Publications and source records attributed to Zawada, K. J..

3 recordsLinked to original sources

bioRxiv2024

Coral reef habitat complexity decreases and diversifies local availability of light

The spatial distribution of environmental conditions can determine where organisms can and cannot live. When the distribution of microhabitats within a landscape is mediated by the shape of its surface, structural complexity can indirectly affect environmental niche distributions. This study investigates how light availability patterns change along a gradient of landscape complexity measured as surface rugosity and height range in tropical shallow reefs. We used 260,000 high frequency and high spatial resolution light measurements across 903 locations to determine the proportion of light that is available at the reef surface. We find that light available on the reef surface is highly variable, with close locations within reef sites experiencing up to 25.7 mol/m2d of daily photon input difference. After accounting for light attenuation due depth, light availability decreases with increasing surface rugosity: a unit increase in local surface rugosity corresponds to an 11-29% decrease in light availability. Local surface complexity can affect the distributions of light availability at local scales, while broader extent site metrics do not capture this variability. Our results suggest that structural complexity enhances local environmental variability, and its indirect effects on other environmental variables and their interactions are essential for understanding ecosystem processes.

ecology↗

bioRxiv2024

habtools: an R package to calculate 3D metrics for surfaces and objects

O_LITechnological advances in three-dimensional imaging techniques have opened the door to advanced morphological analyses and habitat mapping for biologists and ecologists. C_LIO_LIAt the same time, the challenge of translating complex 3D data into meaningful metrics that can be used in conjunction with biological data currently hinders progress and accessibility. C_LIO_LIWe introduce habtools, an R package that provides R functions to efficiently calculate complexity and shape metrics from DEMs, 3D meshes and 2D shapes as well as some helper functions to facilitate workflow. C_LIO_LIWe expect the functionality of habtools to continue to expand as new metrics and faster methods become available, and welcome new contributions and ideas. C_LI

ecology↗

bioRxiv2020

A geometric basis for surface habitat complexity and biodiversity

Structurally complex habitats tend to contain more species and higher total abundances than simple habitats. This ecological paradigm is grounded in first principles: species richness scales with area, and surface area and niche density increase with three-dimensional complexity. Here we present a geometric basis for surface habitats that unifies ecosystems and spatial scales. The theory is framed by fundamental geometric constraints among three structure descriptors—surface height, rugosity and fractal dimension—and explains 98% of surface variation in a structurally complex test system: coral reefs. We then show how coral biodiversity metrics (species richness, total abundance and probability of interspecific encounter) vary over the theoretical structure descriptor plane, demonstrating the value of the theory for predicting the consequences of natural and human modifications of surface structure.Competing Interest StatementThe authors have declared no competing interest.View Full Text

ecology↗