Abstract Detail

Ecology

Drake-Schultheis, Laura [1].

Patterns and distribution of Botryosphaeriaceae fungi related to dieback in big berry manzanita.

Dieback and mortality in wildland plant species due to climate change has been on the rise in recent decades, and latent fungal pathogens may play a significant role in these events. During a severe multi-year drought, canopy dieback associated with latent pathogens in the Botryosphaeriaceae (Bot.) family was observed in stands of a dominant shrub species, big berry manzanita (Arctostaphylos glauca), across chaparral landscapes in California. These fungi are well-known pathogens of woody agricultural species, especially in hosts experiencing stress, yet little is known regarding their occurrence, distribution and impact in wildland systems. We conducted a field survey across an elevational gradient to identify patterns of Bot. infection as they relate to a) A. glauca dieback severity and b) landscape variables associated with plant drought stress. Three hundred individual shrubs across 30 different sites and three elevational categories (low, intermediate, and high) were sampled for occurrence of Bot. fungi, and each collection site was assessed for level of dieback severity. Dieback severity was positively correlated with Bot. isolation frequency and negatively correlated with elevation. Neofusicoccum australe and Botryosphaeria dothidea were the most frequently isolated species, with N. australe being the most common, particularly at lower elevations. However, N. australe isolation frequency was not correlated with dieback severity. Our results confirm the wide distribution of latent Bot. fungi in a wild shrubland system as an endophyte, and provide valuable insight into areas of greatest risk for future shrub dieback and mortality.

1 - UC Santa Barbara, UC Santa Barbara, Santa Barbara, CA, 93106, United States

Keywords:
bigberry manzanita
Arctostaphylos glauca
Drought
Botryosphaeriaceae
latent fungal pathogens.

Presentation Type: Oral Paper
Session: ECO2, Ecology: Invasion Biology
Location: /
Date: Tuesday, July 20th, 2021
Time: 1:30 PM(EDT)
Number: ECO2005
Abstract ID:639
Candidate for Awards:None