Abstract Detail

Ecology

Uhawenimana, Pasteur Migine [1], Eckardt, Winnie [2], Manishimwe, Aloysie [1], DeVore, Melanie [3].

Assessment of mechanical defenses of two Rubus species against herbivores in and around the Volcanoes National Park, Rwanda.

Plants possess a wide array of chemical and mechanical defenses to deter herbivory. Understanding plant responses to herbivory can provide important insight for conservation of both plants and their associated herbivores. Rubus is one of the top five plants consumed by the herbivorous mountain gorilla and is a significant part of other herbivores’ diet in the Volcanoes National Park (VNP) in Rwanda. Rubus have prickles that act as a mechanical defense against herbivores. Several characteristics of prickles can be induced to change in response to increased herbivory. This study aimed to assess mechanical defenses of R. apetalus and R. kirungensis against herbivores in and around VNP. Samples of five individuals of both Rubus species were randomly collected from 24established plots; 12plots inside VNP where herbivory was assumed to be high and 12 plots outside adjacent to VNP where herbivory was assumed to be low. For each sample, prickle length, shape and density were measured, as well as the petiole and rachis length of leaves. We found that inside VNP, prickles of both Rubus sp. are longer, recurved, and densely distributed on stems, petiole, rachis and the main leaf vein. The petioles and rachises were also longer than of samples from outside VNP. Our results suggest that both Rubus species have the plasticity to enhance their defense structures in VNP possibly to persist stress placed on it by increased herbivory, fruit consumption, and trampling activities. The method developed can be applied to monitor long-term plant-herbivory interactions and help to predict changes in the diet of large herbivores and their food availability. Rubus species have remarkable ability to radiate into new habitats, hybridize, change chromosome numbers, and reproduce vegetatively. For this reason, we believe that Rubus is not a species of concern in the park.

1 - University of Rwanda, Huye, Rwanda
2 - The Dian Fossey Gorilla Fund International, Musanze, Rwanda
3 - Georgia College & State University, Biological And Environmental Sciences, Campus Box 081, Milledgeville, GA, 31061, United States

Keywords:
plant defense
Rubus
Gorilla
Virunga Mountains
Rwanda.

Presentation Type: Poster
Session: P1, Ecology Posters
Location: Virtual/Virtual
Date: Monday, July 19th, 2021
Time: 5:00 PM(EDT)
Number: P1EC027
Abstract ID:433
Candidate for Awards:None