Abstract Detail

Conservation Biology

Clonal structure dominates in a native bamboo, Arundinaria appalachiana, on the Cumberland Plateau of Tennessee.

In monocarpic bamboo species, populations are composed of long-lived clones that episodically flower, set seed, then die -- often synchronized at the landscape-level. Arundinaria appalachiana is a recently described bamboo species endemic to the Southern Appalachian Mountains of the Southeastern US. No A. appalachiana population has ever been observed to flower, and recent observations suggest that it is declining in abundance, possibly as a result of fire suppression. On the Southern Cumberland Plateau in Tennessee, the species persists in extensive patches along streams and adjacent slopes. If A. appalachiana is indeed a monocarpic perennial, we hypothesized that within a watershed, one or more clones was previously established by seed after the death of the previous generation of adults. This would result in one of three possible patterns of genetic structure: 1) Patches represent one large genetic individual that was successfully established following the last reproductive event and spread clonally across the site, fragmenting into discrete patches over time; 2) Patches represent separate, genetically distinct clones, all of which represent sexually produced offspring of a large clone that previously occupied the watershed; or 3) Patches representing many genetically distinct clones that are not necessarily siblings. We used a genotype-by-sequencing (GBS) approach to generate data for nearly 60 novel nuclear microsatellite loci for 351 individually mapped culms over two watersheds (Sewanee Domain and Franklin State Forest), and we included four additional culms from different locations in Alabama and a single culm of A. tecta for comparison. Each individual outside of the study area exhibited a unique genotype. Within the Sewanee Domain, five intact A. appalachiana clones were excavated and mapped, then re-mapped after 3 years. Some of the culms included in genetic analyses were included in the excavation study, which allowed us to calibrate our distance threshold for determining clonal assignment. The excavated clones consisted of branched rhizome systems spanning over 100 m2 interconnecting 50 to 100 culms. All excavated clones changed spatial position and became highly fragmented over time. Genetic analyses indicate that the Sewanee Domain site is dominated by a single clone spanning 1 km across with a few, smaller clones primarily along the southern edge of the larger one. In contrast, while clonality was important in the Franklin State Forest site, clones were more evenly distributed across the landscape. We will discuss the evolutionary implications of our findings for the long-term persistence of Arundinaria appalachiana on the landscape.

Related Links:
The Morris Lab website
The Evans Lab website

1 - Furman University, Department Of Biology, 3300 Poinsett Highway, Greenville, SC, 29613, United States
2 - University of the South - Sewanee, Department of Biology, Sewanee, TN, 37383, USA

Keywords:
conservation
population genetics
Southeastern US.

Presentation Type: Oral Paper
Number: CB2005
Abstract ID:808
Candidate for Awards:None