OBJECTIVE: The purpose of the study is to investigate how pulses of precipitation translate into
pulses of plant above ground net primary productivity (NPP) and how the small mammal community
responds to such changes also in relation to shrub gradient across the landscape. Particularly
we are interested in how the energy flows through the ecosystem in response to pulses of rain,
how the small mammal community partition resources (in terms of C3 (forbs and shrubs) and C4
(grasses) plants) and how the genetic structure of some species (i.e.: Dipodomys spp.) is
affected by their population dynamics.
1) Small mammal abundance should respond positively to precipitation and NPP.
2) On a temporal scale, the small mammal energy use should show parallel fluxes along the shrub
3) The small mammal community should consume C3 and C4 plants according to their availability (or
4) At low population density, dispersal should be limited and the genetic variance will be
distributed among populations rather than within (i.e., Fst will trend towards higher values).
After pulses of rain and NPP, population densities will be greater, dispersal prevalent, and
the genetic variance of populations will be distributed within populations (i.e., Fst will
approach zero) as dispersal homogenizes populations.
Variables include rodent species, sex, reproductive status, weight, and maturity status were recorded.
Dry atmospheric fallout (dryfall) is collected monthly using an Aerochem Metrics wetfall/dryfall collector located at the LTER weather station. Each sample is analyzed for NO3, NH4, Cl, SO4, Ca, Mg, Na, K, Total N, & Total P.
Surface evaporation is measured weekly to twice weekly using an evaporation pan compatible with standard National Weather Service evaporation measurements. Measurements are made twice per week during hot periods because of high evaporation rate. The following data is collected: number of days between measurements, beginning and ending measurement period, current, minimum, and maximum water temperature; initial water level; final water level; rainfall since last evaporation measurement, and calculated evaporation (inches).
Hourly summary values of averages of readings of the following parameters are made which are based on data recorded on a Campbell CR10(X) data logger: maximum, minimum, and average air temperature; maximum and minimum relative humidity; total precipitation; average wind speed; maximum wind speed; average wind direction; total incoming solar radiation; average soil temperature at 5cm and 20cm; mean dew temperature. From 1983 - 5 June 1991, readings on which hourly averages are based were made at 12 second intervals. From 6 June 1991 to present, readings on which hourly averages are based are made at 10 second intervals.
This primary purpose of this data set is to validate the LTER Weather Station tipping bucket rain gauge data. The dipstick rain gauge (DSRG) data is measured at least weekly during scheduled maintenance trips to the LTER Weather Station to maintain the evaporation pan water levels. During the summer months this may be twice a week. Additionally, DSRG data is collected after any rain event that requires the collection of the Wetfall/Dryfall precipitation buckets which are located about 10 meters from the DSRG. This is usually any amount greater than 0.02". DSRG data is also collected after very small events when personnel are in the vicinity.
These data are collected to provide a measurement of rainfall at the Biodiversity site. They are Daily Summary data providing daily totals for those dates that precipitation occurred. Values are in millimeters (mm).
These data are collected to provide a measurement of rainfall at the Biodiversity site. They are detailed records providing a time stamp of month/day/year hour:minute:second for each tip of the tipping bucket rain gauge (equal to 0.1 mm of precipitation).
Beginning in 1996, annual photos are taken from each of the 4 corners of each of the 15 70-meter x 70-meter NPP sites between August and November depending on other research activity constraints. The plots were established in early months of 1989. From 1996-2002 photos were taken using 35mm color slide film. Beginning in 2003, digital photos were taken in JPG format. Occasionally, supplemental photos may be taken at the same time that provide additional habitat information at the landscape, patch, or plant species level
A 4" diameter cylindric graduated rain gage (11" x 0.01" capacity) is mounted on a 4x4 inch diameter redwood post or on a wooden exclosure post next to gate at or near the 15 LTER-II NPP sites. Collection is made monthly on the day that monthly soil water content measurements are made to correlate precipitation input with belowground water content. Data is collected primarily from graduated rain gauges. However, when missing data would result otherwise, amounts from the closest rain gauge are used in order to maintain as complete a data set as possible for that site. The rain gauge used is identified with each rainfall record. Other types that may be used are the Standard Can Gauge (DSRG or dipstick rain gauge), Belfort Weigh Bucket Rain Gauge (WBRG), and Qualimetrics Tipping Bucket Rain Gauge (TBRG).
Daily summary values of averages of readings of the following parameters are made which are based on data recorded on a Campbell CR10(X) data logger: maximum, minimum, and average air temperature; maximum and minimum relative humidity; total precipitation; average wind speed; maximum wind speed; average wind direction; total incoming solar radiation; average soil temperature at 5cm and 20cm; mean dew temperature. From 1983 - 5 June 1991, readings on which daily averages are based were made at 12 second intervals. From 6 June 1991 to present, readings on which daily averages are based are made at 10 second intervals.