phycology diatom logo Phycology Section, Patrick Center for Environmental Research

DPDC Frequently Asked Questions

academy of natural sciences philadelphia logo


Phycology Section

Algae Images

Taxa Names


Diatom Paleolimnology Data Cooperative

Autecological Data


Frequently Asked Questions

Why should I contribute my data to the DPDC?

Two main goals of the DPDC are to help scientists understand long-term global change and to improve their techniques for inferring environmental change from diatom data sets. The more data sets that are available in the DPDC the more effectively these goals will be met. Therefore your contributions are important!!

One benefit of a DPDC with many data sets is that it will help foster more efficient and innovative uses of published data. For example, it will make it possible for researchers to go beyond the current region-centered approach by assembling large calibration sets constructed from smaller ones and using them for different purposes than originally envisioned. Additionally, smaller, targeted calibration sets might be investigated by combining subsets of data from various projects and regions. Cores can be reanalyzed and reinterpreted using new calibration sets, and pre-existing core data may for the first time be used for quantitative reconstructions. Data can be used to study the biogeography and ecology of diatoms and can be used in other programs to visualize distributions across space and time. Though the harmonizing of taxonomies that is an essential task when combining different data sets may be a daunting task, it is not necessarily more difficult than any initial study or trying to get funding to create a new large calibration data set.

Another reason for contributing your data is simply that other scientists can use the knowledge you have developed. Being downloadable from the DPDC will make your data more accessible and more likely to be used by other researchers. And in the future, when diatom paleolimnological data are archived in databases that can be accessed by programs such as PaleoVu or SiteSeer, investigators interested in exploring a core location will be able to instantly view existing diatom diagrams, and access literature references and other information, by clicking on a site map.

Another benefit of contributing your results is that diatom paleolimnological data are simply not as widely used in the paleoclimatological community as they might be. A solution is to release our results in a usable fashion to researchers in other disciplines such as climate modelers and paleoclimatologists. The DPDC will make the data available in the same context as other proxy groups data cooperative’s now made available by the NOAA and the NGDC.

Back to top

What do I have to do to submit data to the DPDC?

Please complete and submit a DPDC data entry application. Follow the "How to Submit Data" instructions.

Back to top

My study did not concern paleoclimatology. Do you want it in the DPDC?

If your data concerns a diatom core or surface calibration set from lakes, wetlands, or estuaries somewhere in the western hemisphere and published in a peer-reviewed publication, there is probably some way that it is relevant to studies of global change. If still in doubt, please contact Don Charles at or a DPDC representative at .

Back to top

Just how much of my data do you want?

We would like nearly everything, and the DPDC has been designed to hold nearly everything. However, we are primarily concerned with the crucial minimal basic data.

The minimal data required are raw diatom count info, associated taxa, critical site information, publication references, and information to contact the data contributor (you!). For surface sediment calibration sets, information about environmental variables is required.

Back to top

What computer resources are necessary to use the DPDC data entry application?

The minimum requirements for the application is a PC running Windows 98 or later or Windows NT 4 or later, with 166-MHz or higher processor, and at least 32 MB of system memory. The screen area in your display properties must be set to at least 800 by 600 pixels. The DPDC Data Entry application was created using Microsoft Access 2000. It has been tested on Windows 98, NT, and 2000. Macs are not currently supported.

Back to top

I am not able to download the DPDC data entry application. What do I do?

The DPDC data entry application is rather large and may take a while to download. It may be too large for some computer systems to download successfully. You may request a copy of the DPDC data entry application on CD. Email your name, institution, and address to .

Back to top

I have diatom counts to submit, but very limited amount of supporting data. Should I contribute my data set? OR
I have a rich set of data, but little time available for the data entry process. Do you need all of the data?

Yes in answer to question #1 and no to question #2. Although the DPDC was designed to provide places for storing the wide variety of information that contributors might think necessary to qualify and fully document their data, the Data Entry Application specifies the minimum data that are necessary so that even very basic data sets could be included. Therefore if you have either basic sets of data or little time available, review the instruction manual or the Example Data Entry Application to see fields which are definitely required and those which are optional.

Back to top

What about taxonomic consistency?

NOAA sponsored a workshop in 1994 on taxonomic consistency in the context of forming this database. It was organized and hosted by J. Pat Kociolek and held at the California Academy of Sciences in San Francisco. Participants recommended that due to limited resources, attempting to harmonize the taxonomies of contributed data sets should not be attempted initially. They further recommended that the data structure would allow for the future application of computer techniques to allow users to extract data using one or more taxonomic schemes. Therefore, in order to meet the needs of the paleoclimatological community as quickly as possible, the first priority for the DPDC was to form a flexible database structure and add as much basic data as possible.

There are ongoing research projects which hold out the promise of increased consistency between laboratories regarding taxonomic consistency in identification and nomenclature. As taxonomic synonymy tables are computerized, their application to the existing structure of the DPDC will be a fairly straightforward database operation.

For the present, the current database structure is capable of recording extensive information about the taxonomic views of the contributing researchers - the reference used for each and every taxon entity can be recorded along with notes, location of slide archives, notes on synonymy, a contributor's sense of their overriding taxonomic philosophy, etc. There is room in the database to give a complete picture of the contributor's sense of taxonomy.

Back to top

Is there a current 'taxonomy' being used by the DPDC?


The DPDC taxon list simply records all names (with authors) that are submitted to the database. In this sense, the contributors' taxonomy will always be preserved and retrievable in the basic data. These entries will contain 'errors' (of synonymy, nomenclature, misidentification, etc.) and, of course, simple differences of opinion with future users. Future investigators using the DPDC and attempting to combine data from different sources will need to take this into account.

Back to top

© 1998 - 2017 All Rights Reserved,
The Academy of Natural Sciences of Drexel University, 1900 Benjamin Franklin Parkway, Philadelphia, PA 19103