The Effects of Fire on Parish's horse-nettle

Beginning in 2009, IAE, in cooperation with the Medford BLM, has been conducting a fire ecology experiment in Jackson County in order to create a better understanding of the effects that fire has on the growth and reproduction of Parish’s horse-nettle (Solanum parishii).  Prior to this study, very little experimental research had been conducted looking specifically at this species' response to periodic burning. Controlled burning was conducted on two BLM locations, Hukill Hollow and Woodrat Mountain, with known populations of Parish’s horse-nettle. Fire suppression has occurred in the area since the beginning of the 20^th century when much of the native grassland and oak savannah landscape was converted into pasture and urban space.  However, it is possible that recruitment and survival of S. parishii, along with several other natives could benefit from periodic natural disturbance. 

Parish's horse-nettle is a small perennial in the Solanaceae (potato) family found in dry chaparral communities.  Its native habitat ranges from southern Oregon into Baja California at elevations of less than 2000 feet.   Approximately thirty populations have been documented within the Medford BLM district occurring in Jackson, Josephine, and Curry counties.  In mid-summer the plant produces umbel-like infloresences with white to purple flowers.  After fertilization, the plant produces berries that change from green to purple in color.  Individuals measure less than one meter in height and grow in a branching formation.  The lanceolate leaves exhibit wavy margins and measure between 2 and 7 centimeters long.

In 2009, IAE established 40 sample plots at two locations outside Jacksonville, each plot measuring 3 meters by 6 meters.  Half of the plots were assigned to receive a burn treatment and half were left alone to be control plots.  All S. parishii plants located within the plots were mapped and measured to establish baseline population data.  Data collected included the maximum and perpendicular widths of the plant, the total number of fruits and flowers, and the presence or absence of insect and mammal herbivory.  Controlled burns were conducted in the fall of 2010 and annual monitoring has continued through this year.  Based on 2011 data, there was no evidence of fire effects on reproductive effort (calculated by the sum of fruits and flowers within the population).  However, one of the two sites did exhibit an increase in the mean size of S. parishii plants within burn treatment plots.  Both sites appeared to experience a high level of mammal herbivory.  The final data analysis conducted this year will provide valuable information about whether periodic controlled burning is an effective management tool in areas that host Parish’s horse-nettle populations. 

Demography plot markers at Hukill Hollow

View from Woodrat Mountain

In Search of clustered lady's slipper (Cypripedium Fasciculatum)

Clustered lady's slipper habitat

Clustered lady’s slipper (Cypripedium fasciculatum) is a member of the orchid family that occurs throughout the western states and it is one of only three members of the Cypripedium genus endemic to western North America.  The Bureau of Land Management and the USDA Forest Service have listed the plant as a sensitive species, meaning that the population viability is of concern and the species may require active conservation.  In Oregon, clustered lady’s slipper predominantly occurs within the Klamath mountain region in coniferous forests with steep slopes and dense canopy cover.  The BLM has documented over 800 occurrences of clustered lady’s slipper in the Medford District, but many of the sightings were documented several decades ago.  In order to create a more accurate understanding of the current population, the Institute for Applied Ecology has spent several years revisiting previously documented sites to determine the presence or absence of plants and the quality of the populations.  Clustered lady’s slipper is a relatively small orchid and is identified by its hairy stem and sessile opposite leaves.  A detailed species description can be found here. 

The purpose of this project is to update sighting reports, some of which are 30 years old, with accurate information about the status of the previously documented populations.  Many of the sites were initially discovered during pre-disturbance site surveys for proposed projects.  In the last several years, IAE has predominantly surveyed for  clustered lady’s slipper on BLM lands; in 2012, we focused our surveys on Forest Service sites which tend to occur at higher elevation than the BLM sites.  Information gathered during these site visits will be used to update and reinforce predictions made with the Population ViabilityAnalysis and it could potentially be used to reevaluate the species’ listing.

Budding clustered lady's slipper

Since IAE began revisiting sites in 2008, 64 sighting reports from the BLM have been updated.  To date in 2012, there have been 11 Forest Service sites updated, 3 of which had surviving populations of clustered lady’s slipper.  All of the successful populations were situated on steep slopes with low understory cover and high canopy cover.  Populations that have disappeared since the last sighting often occurred in areas where disturbance had been proposed, such as construction of mining pits, pathways, and timber access.  Surveying will continue throughout the summer in an effort to collect data at as many Forest Service sites as possible.      

The ongoing trend of population decline and local extinction of clustered lady’s slipper populations can be attributed to several causes.  Firstly, the plants are threatened by habitat disturbance, such as mining, logging and maintenance of gas and power lines.  Such disturbance can alter hydrological patterns and increase light exposure.  Secondly, as the PVA has predicted, populations with fewer individuals have a greater risk of extinction.  More than half of the documented populations in Oregon have fewer than ten plants, putting them at greater risk.   Clustered lady’s slipper is a non-rewarding species, meaning that it is difficult to attract pollinators since there are no nectar benefits. In addition, there is little evidence of seedling recruitment.  IAE will continue to revisit BLM and Forest Service sites working to update enough information to describe the current status of clustered lady’s slipper populations.      

Cypripedium fasciculatum

Population Monitoring of Calochortus greenei

In 2000, President Clinton designated 53,000 acres of federal land in South Oregon as a national monument due to the high variety of species in a geographically small area.  The Cascade Siskiyou National Monument is the first monument in the nation that has been set aside solely for the protection of biodiversity.  The monument’s extreme diversity can be partially attributed to its geographic location at the convergence of three distinct ecosystems; the Great Basin, the Cascade Range, and the Siskiyou Mountains.  In 2009, President Obama approved an expansion of land protection allowing 23,000 acres of the monument to be designated as the Soda Mountain Wilderness.  Federal wilderness protection ensures the highest level of habitat preservation by disallowing motorized activity and asking visitors to abide by the “Leave No Trace” policy.

Calochortus greenei. (L) flower buds, (R) basal leaf within exclosure

Botanic diversity is high throughout the monument due to the extreme differences in elevation, soil composition and hydrology.  Many endemic species can be found in this area where the eastern Oregon desert meets the western Oregon fir forests. One of the unique species present in the monument is Calochortus greenei, a mariposa lily that has been listed as a species of concern in Oregon and California.  There has recently been a proposal to change the listing to "threatened" in the state of Oregon. Calochortus greenei  (Greene’s mariposa lily) is a member of the lily family that reaches 10-30cm in height and has a large basal leaf that is glaucous (waxy) on both sides.  The flowers, which bloom in mid-summer (our monitoring occurs in mid-June, when the plants are still in bud), are pink to purple in color and are extremely hairy on the inner surface. A detailed species description can be found here.  Greene’s mariposa lily tends to coexist with a similar species, the Tolmie star-tulip, which flowers slightly earlier in the year. 

Monitoring demography plots

The Institute for Applied Ecology has conducted a 10-year study on the effects of mammal herbivory by constructing permanent large mammal exclosures (targeting the exclusion of deer and elk) paired with uncovered control plots.  In addition, “all-mammal” exclosures (targeting the exclusion of rodents) were installed at two of the three study areas.  The study areas were originally designed to provide a range in terms of intensity and duration of cattle grazing, but all grazing ceased in 2009.  At each site, demography plots were established to track the survival of individual plants.  Greene’s mariposa lily is capable of entering a dormancy phase and then reappearing, so monitoring across several years was necessary to accurately describe survival rates.  2012 was the final year of monitoring and all of the data collected will be used to produce a Population Viability Analysis and to make recommendations for future management.

Large mammal exclosure at Colestine study area

Several of the monitoring sites were difficult to reach given the minimal usage of roads throughout wilderness lands.  Luckily, we had the help of a BLM botanist who knew the backroads well and was able to winch a fallen tree out of the road so that we could reach one of the monitoring sites.  The various study areas ranged in elevation and many provided fantastic views of Mt. Shasta and Mt. Ashland.  Wildlife sightings included gopher snakes, several species of raptors, and a bobcat.  A variety of plant species were flowering, including harsh Indian paintbrush (Castilleja hispida), blue-eyed grass (Sisyrinchium idahoense), silvery lupine (Lupinus argenteus) and carrot-leaf horkelia (Horkelia daucifolia).

IAE 2012 Conservation Research crew (Mt. Shasta in background)

Fritillaria gentneri Population Monitoring in Josephine County

2012 IAE conservation crew interns Guy and Charlotte conducting a demographic survey of Fritillaria gentneri in Josephine county.

In the third week of April, the conservation crew monitored a population of Gentner’s Fritillary, scientific name Fritillaria gentneri Gilkey, on Picket Creek in the Siskiyou Range to the southwest of Grant’s Pass, Oregon.  Our monitoring of this species is tied to the flowering season because it cannot be distinguished from the two ‘parent’ species F. recurva (scarlet fritillary) and F. affinis (chocolate lily) vegetatively and the distribution of these three species overlap throughout the range of fritillary.

Fritillaria gentneri found in our monitoring was counted as an R2 meaning "a reproductive individual with two blooms. The highest ranking we recorded for number of flowers we found on one individual this year was an R7!

            Gentner’s Fritillary is a rare lily endemic to a limited range in the Klamath-Siskiyou region of southern Oregon and northern Californa.  It is listed as an endangered species by both the state of Oregon and the U.S. Fish and Wildlife Service. A detailed description of Genter's frittilary can be found in 2011’s blog entry for Gentner's fritillary via this link. http://research.appliedeco.org/2011/04/population-monitoring-of-fritillaria.html

There are several aspects that lead to the vulnerability of Gentner’s Fritillary.  It is a mid-successional species found in dry hillsides in open canopies of oak woodlands and chaparral shrub communities.  It is also present mixed hardwood forests, coniferous forests and grasslands at elevations, and in all of these ecotypes from 600 to 4,450 ft.   Fire suppression in many of these normally fire prone habitats has lead to encroachment by trees and shrubs which at lower densities would provide useful cover.  Housing and agricultural development, exotic grass encroachment, yellow star thistle (Centaurea solstitialis) and associated herbicide treatments, horticultural collecting, mining, wildlife grazing, logging, and possible climatic limitations on reproduction are additional pressures on the species.

Gentner's fritillary has low genetic diversity due to the relatively few and isolated events of hybridization between scarlet fritillary and chocolate lily that created the species.  Many populations of Gentner's fritillary are sterile clones that propagate only by producing numerous tiny bulblets.  Viable seed is known to be produced in larger populations because of the presence of sufficient genetic variation to navigate the substantial genetic safeguards present in many lilies that inhibit inbreeding. Efforts at creating viable seed have been successful when cross-pollinating from different populations.

A view uphill typical of the lower slope of our Picket creek monitoring site, oak grassland with a steep grade.

The steep and shallow soils with mild serpentine influence contribute to the set of conditions at Pickett Creek that provide suitable habitat for Gentner's fritillary.  It's presence at this site with shallow soils and dry summers is indicative of F. gentneri’s drought tolerance, and the serpentine influence in the soils reveal the species’ tolerance for adverse soil chemistry.  Serpentine soils are high in heavy metals and trace minerals, low in vital nitrogen, phosphorus and potassium, and have a low calcium to magnesium ratio, all factors that create conditions normally toxic to most plant species.

           Gentner's fritillary stands a good chance for recovery through the continued monitoring and conservation efforts by government agencies and entities like IAE, and the raising of public awareness of this charismatic species.