Theses and Dissertations

Date of Award


Document Type


Degree Name

Master of Science (MS)


Ocean, Coastal, and Earth Sciences

First Advisor

Dr. Alejandro Fierro-Cabo

Second Advisor

Dr. Carlos E. Cintra-Buenrostro

Third Advisor

Dr. Ika Feller


The multiple experiments conducted in an Avicennia germinans forest in Laguna Vista, TX was focused on determining if facilitation theory could explain the behavior observed between the herbaceous halophyte Batis maritima and A. germinans. I hypnotized that a positive interaction exists but through which mechanisms of facilitation I did not know. The overarching theme of the study is the presence or absence of B. maritima. Facilitation theory tells us that positive interactions are most often found under stressful conditions such as those on the coastal tidal flat of the Laguna Madre. Locally B. maritima has been found to colonize tidal flats following a disturbance or prior to the arrival of mangrove seedlings. To elucidate this idea, I conducted multiple seedling and propagule experiments. I found significant interactions that correspond with several of the mechanism of facilitation theory. Microclimatic conditions were shown to have been significantly affected by the presence of B. maritima. Air temperature was reduced by B. maritima foliar shading which was confirmed by the reduction in light intensity from April – September. Growth responses for A. germinans height showed a significant preference for the B. maritima treatment. Survivability of A. germinans seedlings was greatly increased within B. maritima patches. All seedlings growing in the absence of B. maritima died before the experiment was over.


Copyright 2020 Javier R. Navarro. All Rights Reserved.