Abstract Detail

Symbioses: Plant, Animal, and Microbe Interactions

Gonzalez-Orellana, Normandie [1], Salazar-Mendoza, Aragne [2], Ackerman, James [3], Bayman, Paul [4].

Highly Vagile but Rare: What Limits the Local Distribution of a Rare Epiphytic Orchid?

Most orchid species are tropical epiphytes, and their dispersion is often characterized by small, scattered populations. The availability of suitable host trees (phorophytes) may not only affect orchids but also their mycorrhizal fungi on which they depend for successful germination. As orchids produce thousands of wind-dispersed seeds in every fruit, metapopulation dynamics are thought to be more limited by seed germination and establishment than by dispersal. Although abiotic factors such as precipitation, temperature, and light certainly affect seed germination and establishment, we expect that bark characteristics of host trees and availability of mycorrhizal fungi are paramount.
The research addresses the relationships of Psychilis kraenzlinii (peacock orchid) with its mycorrhizal fungi and phorophytes to elucidate how these affect the dispersion of the orchid within a local population in the Susúa State Forest, a tropical moist forest of Puerto Rico. First, we ask whether there is a difference in occupation of phorophyte species and/or phorophyte physical characteristics or not. Next, we aim to identify the orchid mycorrhizal fungi that trigger seed germination and development. Lastly, we will use these data to address the paramount question: Which biotic and abiotic factors most influence the distribution of this orchid?
Herein we present preliminary data for the first phase of the project. Psychilis kraenzlinii was found growing on 14 phorophyte species. A loglinear analysis was used to address whether any of the 14 species has a significant association with the presence of the orchid. Coccoloba microstachya and Oplonia spinosa had a negative and positive effect over the presence of the orchid, respectively. We also found that most orchids grow towards the southwest and under 75 cm above ground.
The next step of the investigation is to describe the physical characteristics of the phorophytes to see if there is an association with certain characteristics like water storage capacity (WSC) or rhytidome texture. These characteristics have been identified as important influencers of the presence of epiphytic orchids. Finally, in situ and in vitro seed germination will be done to see if the patterns of the presence of adult orchids are mirrored by seed germination.
Understanding the relationship of orchids with other organisms and with their environment will help us elucidate their evolutionary history and to understand their outstanding diversity. Understanding these relationships is also critical to develop conservation strategies.

1 - POBOX 1153, San Lorenzo, 00754, Puerto Rico
2 - University of Puerto Rico, Rio Piedras, Biology Department, 30 Buenos Aires, Parada 27, San Juan, Puerto Rico, 00911, Puerto Rico
3 - University Of Puerto Rico, Biology, 17 Avenida Universidad Suite 1701, San Juan, PR, 00925, United States
4 - Universidad De Puerto Rico - Rio Piedras, Biologia, PO Box 23360, UPR Biologia, San Juan, 00931, Puerto Rico

Keywords:
orchids
Epiphytes
Mycorrhizae
host specificity
conservation.

Presentation Type: Poster
Session: P3, Symbioses: Plant, Animal, and Microbe Interactions Posters
Location: Virtual/Virtual
Date: Wednesday, July 21st, 2021
Time: 5:00 PM(EDT)
Number: P3SM001
Abstract ID:694
Candidate for Awards:None