The Native Vegetation Protection Law of Brazil and the challenge for first-order stream conservation

First-order streams in Brazil are protected by the Native Vegetation Protection Law of Brazil (NVPL), which regulates the land-use in rural properties and is linked with aquatic conservation. We investigated the importance of the data-set resolution to identify first-order streams (State of Sao Paulo, Brazil) and estimated its length compared to other water bodies. We found that first-order streams represent around 58% of the total length of the drainage system. In addition, we compared this database with that of the Environmental Rural Registry (CAR in Portuguese). Compared with the lower resolution data-set, the length of first-order streams self-declared in CAR was 80% lower. We also found a concerning number of small dams in first-order streams, which severely changes their dynamics. Therefore, we recommend the use of finer resolution data-sets in order to create tools to support legal compliance that goes beyond the limited information provided by CAR.