{ "currentVersion": 10.91, "cimVersion": "2.9.0", "id": 4, "name": "Current Probability of Occurrence", "type": "Feature Layer", "description": "

This dataset is one of a suite of products from the Nature\u2019s Network project (<\/SPAN>naturesnetwork.org<\/SPAN><\/A>). Nature\u2019s Network is a collaborative effort to identify shared priorities for conservation in the Northeast, considering the value of fish and wildlife species and the natural areas they inhabit. Brook Trout probability of occurrence is intended to provide predictions of occupancy (probability of presence) for catchments smaller than 200 km2 in the Northeast and Mid-Atlantic region from Virginia to Maine. The dataset provides predictions under current environmental conditions and for future increases in stream temperature. Brook Trout probability of occurrence (under current climate) is one input used in developing \u201cLotic Core Areas, Stratified by Watershed, Northeast U.S.\u201d that is also part of Nature\u2019s Network. Lotic core areas represent intact, well-connected rivers and stream reaches in the Northeast and Mid-Atlantic region that, if protected as part of stream networks and watersheds, will continue to support a broad diversity of aquatic species and the ecosystems on which they depend. The combination of lotic core areas, lentic (lake and pond) core areas, and aquatic buffers constitute the \u201caquatic core networks\u201d of Nature\u2019s Network. These and other datasets that augment or complement aquatic core networks are available in the Nature\u2019s Network gallery: <\/SPAN>https://nalcc.databasin.org/galleries/8f4dfe780c444634a45ee4acc930a055.<\/SPAN><\/A><\/P>

Intended Uses<\/SPAN><\/P>

In the context of Nature\u2019s Network, this dataset is primarily intended to be used in conjunction with the product \u201cLotic Core Areas, Stratified by Watershed, Northeast U.S.\u201d to better understand the importance of core areas to Brook Trout. It also can be used on its own to identify priority watersheds for Brook Trout. <\/SPAN><\/P>

The dataset was originally developed for and is part of the Interactive Catchment Explorer (ICE). ICE (<\/SPAN>http://ice.ecosheds.org/) <\/SPAN><\/A>is a dynamic visualization interface for exploring catchment characteristics and environmental model predictions. ICE was created for resource managers and researchers to explore complex, multivariate environmental datasets and model results, to identify spatial patterns related to ecological conditions, and to prioritize locations for restoration or further study. ICE is part of the Spatial Hydro-Ecological Decision System (SHEDS).<\/SPAN><\/P>

Description and Derivation<\/SPAN><\/P>

The dataset provides predictions under current environmental conditions and for future increases in stream temperature of 2, 4, and 6 degrees Celsius. It employs a logistic mixed effects model to include the effects of landscape, land-use, and climate variables on the probability of Brook Trout occupancy in stream reaches (confluence to confluence). It includes random effects of HUC10 (watershed) to allow for the chance that the probability of occupancy and the effect of covariates were likely to be similar within a watershed. The fish data came primarily from state and federal agencies that sample streams for Brook Trout as part of regular monitoring. A stream is considered occupied if any Brook Trout were ever caught during an electrofishing survey between 1991 and 2010. The results are based on more than 15,000 samples from more than 13,000 catchments from all 13 Northeast states.<\/SPAN><\/P>

Factors that had a strong positive effect on Brook Trout occupancy included percent forest cover and summer precipitation. Factors that had a strong negative effect on occupancy included July stream temperature, percent agriculture, drainage area, and percent upstream impounded area.<\/SPAN><\/P>

Estimates of the probability of occupancy for each catchment with increases in stream temperature of either 2,4 or 6 degrees C are also provided. To provide these estimates, the input values for mean July stream temperature were simply increased by 2, 4, or 6 C and estimated occupancies recorded.<\/SPAN><\/P>

More technical details about the Brook Trout probability of occurrence product are available at: <\/SPAN>http://conte-ecology.github.io/Northeast_Bkt_Occupancy/. <\/SPAN><\/A>Technical details about the regional stream temperature model, which is used in predicting Brook Trout occupancy, are available at: <\/SPAN>http://conte-ecology.github.io/conteStreamTemperature_northeast/.<\/SPAN><\/A><\/P>

Known Issues and Uncertainties<\/SPAN><\/P>

As with any project carried out across such a large area, this dataset is subject to limitations. The results by themselves are not a prescription for on-the-ground action; users are encouraged to verify, with field visits and site-specific knowledge, the value of any areas identified in the project. Known issues and uncertainties include the following:<\/SPAN><\/P>