Demography

Kristin Haskins and Sheila Murray,The Arboretum at Flagstaff

In 2013, The Arboretum at Flagstaff partnered with the Center for Plant Conservation and the Bureau of Land Management in New Mexico to examine conservation concerns of Chihuahua scurfpea (Pediomelum pentaphyllum), a tuber-forming legume. Our primary objective was to determine any changes in population size. In 2015, we established two demography study plots representing two different populations. The ability to retract aboveground tissues underneath the soil is a common drought adaptation found in desert-dwelling species. We were challenged in establishing these plots by the ephemeral nature of aboveground presence of biomass needed to identify the species. The timing of plot site selection coincided with a winter that received average to above average precipitation, improving the likelihood of scurfpea plant emergence, and insuring that plots were indeed placed to capture multiple individuals. Furthermore, the duration of annual monitoring visits was set at 6-years to capture the minimum required 3-years of data for determining population projections, despite potentially uncooperative weather patterns. We recently collected our 5th year of data. Upon completion, these data will be analyzed and suggestions shared with land managers at the BLM in New Mexico and Arizona.

Contributing Author(s): 
Date Recorded: 
Friday, May 3, 2019

Daniella DeRose, Chicago Botanic Garden

Chicago Botanic Garden’s Plants of Concern (POC) program is a collaboration between citizen scientists, natural resource managers, and researchers to collect data on rare plant populations in northeastern Illinois. The primary goal is to identify best conservation practices, while creating awareness and providing education on why conservation matters. POC engages citizen scientists, collects census data on rare plant populations—including identifying invasive species, threats, and evidence of management—and provides data to land managers. Data generated by POC inform the Illinois rare species listing process and are used by land managers to understand population trends and prioritize activities. Program monitors also serve as ecological site stewards. POC has monitored 292 species and 2453 populations, trained 953 volunteers, and worked with 135 landowners as of December 2018. POC trains its citizen scientists to collect standardized data. Partners include volunteer groups, government agencies, private landowners, and researchers.

POC is learning how management impacts rare species. Hill’s thistle, Cirsium hillii, is a habitat specialist threatened by habitat loss and lack of management. Although monitoring and management data suggested that burning and brush removal increase population size, in-depth study revealed a discrepancy between census size and effective population size. POC founder Susanne Masi led level 2 monitoring efforts looking at demography of C. hillii. CBG scientist Jeremie Fant & MS students Abigail White and Nora Gavin-Smyth found that most populations are highly clonal. Self-incompatibility, low flowering rates, and lack of compatible mates lead to low/no seed set, but genetic augmentation (introduced pollen) is able to reduce mate limitation. Based on these results, POC modified its monitoring protocol for C. hillii, introducing a minimum size for identifying individuals. CBG scientist Jacob Zeldin developed new micropropagation techniques that allow for the rapid and controlled cloning of individual C. hillii genotypes year-round with minimal space and materials. Land managers are now interested in using genetic augmentation for this species, sharing genetic material between sites.

Date Recorded: 
Thursday, May 2, 2019

Are others collecting demographic data from reintroduced populations?

I'm interested in comparing reintroduced populations to wild populations of the same species to assess reintroction "success" relative to wild sites.  Are others collecting this kind of data?

rare plant demography data for at least 5 years?

CPC is interested in exploring several questions using long-term rare plant demography data.  Interested?

Jennifer Neale, Denver Botanic Gardens

As scientific programs at Denver Botanic Gardens continue to grow we are working to standardize data collection across all projects to enhance and improve data utility. We have developed uniform protocols for documenting biodiversity for all studies whether they regard demographic studies, ecological monitoring, seed conservation, or floristic surveys. Collection of specimens and associated tissue samples has been incorporated into all studies, along with a methodical approach for tracking field photography, to ensure robustness, consistency, and cross-application of data. With the implementation of these new protocols we are readily able to share data with larger platforms such as the Global Genome Biodiversity Network (GGBN), Integrated Digitized Biocollections (iDigBio), and the Global Biodiversity Information Facility (GBIF).

Contributing Author(s): 
Date Recorded: 
Friday, May 4, 2018

Kristin E. Haskins and Sheila Murray (The Arboretum at Flagstaff), and Andrea Hazelton (Desert Butte Botany)

Acquisition of a long-term dataset is truly rare and can represent decades of hard work and thousands of dollars or more in exhausted resources. The standard model of monitoring year after year is unsustainable for most organizations and begs the question, when should it stop? The Arboretum at Flagstaff has a demography data set for Arizona cliffrose (Purshia subintegra) that has been on-going since 1996. Different ‘levels’ of monitoring have occurred over the years depending on available resources. With some recent funds, we set out to address the following questions with long-term data: 1) What is the long-term viability of the population? 2) Which life stages are most important to capture in the monitoring? And 3) can we monitor less often and still capture important life history events? Challenges included determining starting population sizes for population matrix models and gaps in data. Using the 22 years of monitoring data combined with data from published papers, anecdotes, and historic weather data, we produced population growth rates for P. subintegra and identified key life stages correlated with precipitation events, thus enabling implementation of a modified monitoring protocol, which will conserve valuable resources.

Contributing Author(s): 
Date Recorded: 
Friday, May 4, 2018