Willow Beetle Project

Catalog of Survey and Datalogger Sites, with Links to Datafiles

Inverted cup placed about 2/3 of the way up from the ground in a willow bush. Inside is a HOBO "pendant" temperature logger. This photo is from a site above Green Lake in the Bishop Creek drainage.

Overview

The drainages chosen for the willow leaf beetle study all support long term populations of C. aeneicollis. Some drainages run east-west while other run north-south. All originate in high alpine habitats well above treeline. The site map illustrates the orientation and elevation gradient for the major drainages surveyed in the study. The study sites with location data are listed in a "filemaker pro" file called "beetle site info.fp5" and also in an excel file "beetle_site_info.xls". You can also see the site locations interactively using the Google Earth file google earth coverage of study sites.

The physiological temperature for small-bodied exotherms such as willow leaf beetles is nearly always at or above the ambient air temperature, with solar radiation as an additional heating factor in some situations. In order to analyze and predict the effects of elevation, air temperature, and climate change on the willow beetle system, we needed to monitor air temperatures and precipitation in the approrpiate microhabitats at the various study sites. This has been accomplished using data sets derived from different monitoring efforts:

1981-present precipitation data and standard air temperatures

Air temperatures and snow accumulations (precipitation) have been monitored since the early 1980's in Big Pine Creek, Bishop Creek (South Lake and Sawmill stations), Rock Creek (Rock Creek Lake) and many other areas in the Eastern Sierra. These data are available from the California Data Exchange Center (CDEC) at the web site Locator tool for finding weather stations and data (California Department of Water Resources) The map function at site can be used to locate the dozens of stations in the Owens Valley and in the Eastern Sierra, and to retrieve data as far back as 1902. In many cases precipitation data is available as well. The historical data is presented along with the long term average for the site, which makes it relatively easy to fill in missing values by extrapolation from adjacent sites. In this way a nearly continuous record of precipiation has been generated for the South Lake site (see South Lake precip excel file). However, this site has failed in some years and a regional precipitation metric can also be used: in this case the Owens River runoff measurements. This is not a bad proxy as our study sites are all located along the primary streams feeding the Owens River.

2000-present Salix foliage air temperatures, soil temps, and relative humidity

In the year 2000 we began deploying air temperature dataloggers at sites spanning the beetles' distribution in several drainages (see excel file for a catalog of logger sites). Coin-sized temperature loggers were placed in Salix foliage about 1/3 of the distance inside the crown of foliage, which was .5 to 1.5 m above ground depending on the site. Loggers were shaded from direct sunlight by suspending them inside white plastic cups hanging from a small branch. Loggers were programmed to record temperature on a half-hourly (30 minute) basis. Data has been downloaded once or twice annually to create continuous CUP foliage air temperature records, and dataloggers replaced as needed.

Starting in June 2009 we also began logging temperatures at the base of the plant, 10 cm deep in the soil , and inside a HOBO PRO radiation shield. We also are logging relative humidity inside the same shield. Currently (summer 2011) we are logging every 30 minutes from 5 instruments: CUP temp, BASE temp, SOIL temp, PRO temp, and PRO RH. However, many of the PRO units failed in 2010 and 2011, and we plan to only operate the PRO units in summer starting in June 2012. Also in 2009 we began logging temperature, relative humidity and solar radiation from a set of pole-mounted weather stations, with 9, 10, and 11 thousand foot elevation stations in Big Pine, Bishop and Rock Creeks, and two additional stations in Big Pine Creek. These additional measurements provide context for interpreting the long term record of CUP measurements as well further quantifying the willow beetles' environment (see climate data strategy page for more info).

Raw data files have been archived in the WMRS data center, in the native "HOBOware" or "boxcar" format. These files are all available on the willow beetle ftp site . To get these files you will need ftp client software (e.g. the free "filezilla" download), and a password, which you may get from us by emailing John Smiley at jsmiley[at]ucsd[dot]edu.

The raw data HOBO files have then been filtered and the daily max, min and mean have been stored in one of 5 "filemaker" database files named "CUP temp logger data.fp5," "BASE temp logger data.fp5," "SOIL temp logger data.fp5," "PRO temp logger data.fp5," and "PRO RH logger data.fp5" These files are then used to create delimited text files for import into statistical analysis programs. This data set includes the "core" CUP logger stations that have been monitored continuously since 2000, and which may be used for analysis of long term trends, and the set of "newer" stations that add new sites and/or new variables extending the analysis upward in elevation or into new drainages. See climate data strategy page for more discussion of weather data and analysis for the beetle project. Port 81

The temperature records also reveal the dates of snow burial and snow melt for the logger each winter, dates which have been recorded in a separate "snowmelt" file. This file is also kept in the WMRS data center an as excel file "snowdays analysis.xls". The new BASE temp logger series of data will be very useful in analysis of snow cover at each site.

C. aeneicollis abundance survey results

We have carefully resurveyed the same sites several times each year since 1998. The basic protocol is to relocate survey sites using GPS, and then to make two 5 minute counts, using a handheld counter. Adults, larvae, pupae, and new adults are counted separately. Data are recorded in an excel file ("Beetle Abundance Data Master.xls").