Changes in the quantity and quality of precipitation as it passes through vegetative cover are important components of both hydrologic and nutrient budgets.
Throughfall over any period depends on the balance between precipitation, evaporation and canopy storage (Horton, 1919; Leonard, 1967; Rutter et al., 1972). If the watershed is divided into different vegetation types based on similarity in throughfall and steamflow, the total throughfall over the watershed can be expressed as:
(1) Pg = Sum( T n A n )+ Sum (Sm Dm)
Where Pg = total throughfall reaching the ground, Tn = canopy throughfall from vegetation type n, An = area of vegetation type n, Sm = stemflow from stem type m and Dm = number of stems in type m.
Using eqn. (1) to estimate total watershed throughfall becomes a problem of determining the minimum number of vegetation types necessary to describe the system at the required level of accuracy. In one of our studies, measured throughfall was compared with actual canopy and stem conditions to estimate the percentages of throughfall for different time periods was calculated by weighting the average throughfall and stemflow measured in representative areas of each vegetation type by the total area of that vegetation group.
Measurements reported here were made in two of the Bisley Research Watershed of the U.S. Forest Service. These adjacent watersheds drain 13.0 ha of highly dissected mountainous terrain that range in elevation from 265 to 455 m. Both watersheds are covered by Tabonuco type forests and were selectively logged at various times between 1860 and 1940 (Scatena, 1988).
The dominant tree in the watersheds in the Tabonuco ( Dacryodes excelsa ) which often comprises as much as 35% of the canopy ( Wadsworth, 1970). Structurally the forest has three dominant layers, a discontinuous emergent strata, a continuous upper stratum at 20 m, and an understory layer. Leaves are mesophyllous and often covered with epiphytic growth.
Hydrology, Water Chemistry
XML is in ISO-19115 geographic metadata format, compatible with ESRI Geoportal Server.
Citation for This Dataset
Scatena, F.N., IITF, Heartsil-Scalley, IITF. Bisley weekly throughfall flux. 2013. https://www.sas.upenn.edu/lczodata/content/nutrient-fluxes-rainfall-and-throughfall-bisley-watersheds
Citation for This Webpage
Scatena, F.N.; IITF; Heartsil-Scalley (2002). "CZO Dataset: Bisley - Overland Water Chemistry, Nutrient Fluxes, Rainfall Chemistry, Throughfall Chemistry (1988-2002) - Includes Weekly Rainfall flux." Retrieved 15 Jun 2019, from http://criticalzone.org/national/data/dataset/2626/
Data Use Policy
1. Use our data freely. All CZO Data Products* except those labelled Private** are released to the public and may be freely copied, distributed, edited, remixed, and built upon under the condition that you give acknowledgement as described below. Non-CZO data products — like those produced by USGS or NOAA — have their own use policies, which should be followed.
2. Give proper citation and acknowledgement. Publications, models and data products that make use of these datasets must include proper citation and acknowledgement. Most importantly, provide a citation in a similar way as a journal article (i.e. author, title, year of publication, name of CZO “publisher”, edition or version, and URL or DOI access information. See http://www.datacite.org/whycitedata). Also include at least a brief acknowledgement such as: “Data were provided by the NSF-supported Southern Sierra Critical Zone Observatory” (replace with the appropriate observatory name).
3. Let us know how you will use the data. The dataset creators would appreciate hearing of any plans to use the dataset. Consider consultation or collaboration with dataset creators.
*CZO Data Products. Defined as a data collected with any monetary or logistical support from a CZO.
**Private. Most private data will be released to the public within 1-2 years, with some exceptionally challenging datasets up to 4 years. To inquire about potential earlier use, please contact us.
Data Sharing Policy
All CZO investigators and collaborators who receive material or logistical support from a CZO agree to:
1. Share data privately within 1 year. CZO investigators and collaborators agree to provide CZO Data Products* — including data files and metadata for raw, quality controlled and/or derived data — to CZO data managers within one year of collection of samples, in situ or experimental data. By default, data values will be held in a Private CZO Repository**, but metadata will be made public and will provide full attribution to the Dataset Creators†.
2. Release data to public within 2 years. CZO Dataset Creators will be encouraged after one year to release data for public access. Dataset Creators may chose to publish or release data sooner.
3. Request, in writing, data privacy up to 4 years. CZO PIs will review short written applications to extend data privacy beyond 2 years and up to 4 years from time of collection. Extensions beyond 3 years should not be the norm, and will be granted only for compelling cases.
4. Consult with creators of private CZO datasets prior to use. In order to enable the collaborative vision of the CZO program, data in private CZO repositories will be available to other investigators and collaborators within that CZO. Releasing or publishing any derivative of such private data without explicit consent from the dataset creators will be considered a serious scientific ethics violation.
* CZO Data Products. Defined as data collected with any monetary or logistical support from a CZO. Logistical support includes the use of any CZO sensors, sampling infrastructure, equipment, vehicles, or labor from a supported investigator, student or staff person. CZO Data Products can acknowledge multiple additional sources of support.
** Private CZO Repository. Defined as a password-protected directory on each CZO’s data server. Files will be accessible by all investigators and collaborators within the given CZO and logins will be maintained by that local CZO’s data managers. Although data values will not be accessible by the public or ingested into any central data system (i.e. CUAHSI HIS), metadata will be fully discoverable by the public. This provides the dual benefit of giving attribution and credit to dataset creators and the CZO in general, while maintaining protection of intellectual property while publications are pending.
† Dataset Creators. Defined as the people who are responsible for designing, collecting, analyzing and providing quality assurance for a dataset. The creators of a dataset are analogous to the authors of a publication, and datasets should be cited in an analogous manner following the emerging international guidelines described at http://www.datacite.org/whycitedata.