An NSF-sponsored intersite hydrology project titled 'Intersite hydrological comparison and synthesis at Long Term Ecological Research (LTER) sites' is currently being carried out by Dr David Post. Thus far, this study has concentrated on accumulating data from, and analysing the hydrologic response of five sites - H. J. Andrews (HJA), Coweeta (CWT), Hubbard Brook (HBR), Luquillo (LUQ), and Caspar Creek (CAS).
We now wish to extend this study by incorporating data from a number of other LTER and non-LTER sites, as well as to attempt to address some of the aims of the overall study. To this end, we have convened a workshop to address the objectives outlined below. Invited to the workshop are site representatives, leaders in relevant cross-LTER site fields (ie. climate and vegetation studies), and modellers involved in cross-site comparative analysis.

To examine the relative controls of climate and vegetation on catchment hydrology over a range of timesteps. This will be achieved by addressing the specific issues outlined below.

Climate
- Influence of the snowpack as a mechanism for storage of water. Hypothesised that water stored in the snow is less available for transpiration, producing higher runoffs. This may be mitigated by deep soils which can recharge as the snow melts (HJA). Comparison between high (HBR), medium (HJA), low (CWT) and no (LUQ) snow sites.
- Seasonality of amount, and form (ie snow vs rain) of precipitation. Hypothesised that where the available precipitation overlaps with the vegetation growing season, lower streamflows result. This can either result from the temporal distribution of the precipitation (HJA, CAS), distribution of the growing season (CWT vs LUQ), or form of the precipitation (HBR vs CWT).
- Precipitation amount. Impact where seasonality is the same. Impact at both highly seasonal (HJA vs CAS) and evenly distributed sites (CWT vs LUQ).
- Climate change. Impact of change and variability in total volume, form (snow vs rain), or seasonal distribution (HJA) of precipitation.

Vegetation
- Impact of coniferous Vs broadleaf vegetation on water yield (HJA, CAS Vs CWT, HBR), at annual, seasonal and daily timesteps.
- Impact of forestry treatments on streamflow - comparison between treatments in coniferous and broadleaf vegetation (HJA, CAS vs CWT, HBR).
- Comparison of vegetation water use between catchments at each site and impact on water yield. Requires detailed information on catchment scale vegetation (HJA, CAS, CWT, HBR, LUQ) as well as information on vegetation water use (plant physiology).

To facilitate interactions among the LTER and non-LTER sites on hydrology issues, in a similar way to that initiated by the climate, remote sensing, and stream ecology groups in the LTER network. One way of doing this will be through the production of a publication (with on-line access), describing the relevant landscape attributes of the small experimental catchments at each of the sites. In conjunction with this, access will be provided to on-line hydrology data bases from each of the sites for researchers interested in engaging in intersite hydrological analysis.