Disordered anthropic action causes relevant impacts on different ecosystems. This may endanger key species and the compounds they produce, which have potential for commercial development. We collected environmental samples from the Bela Vista Biological Refuge, belonging to ITAIPU/Brazil, over a period of three years. A total of 181 fungal species were isolated and evaluated for cellulases and xylanases, 74% of which were classified as good enzymatic producers, with a production of up to 50 U/mL of xylanase and 7 U/mL for cellulase. A total of 34 isolates were selected and identified by amplification of internal transcribed spacer regions and then analyzed in BLASTn with 89-99% similarity/identity with others deposited in GenBank; the genera found were Aspergillus, Penicillium, Chaetomium, Clonostachys, Fusarium, Hypocrea, Paecilomyces, Thermoascus, Thermomyces, and Trichoderma. The enzymatic data reveals details of the roles of this biological community. The ability of these fungal species to utilize plant cell wall compounds discovered based on bioprospecting analysis of this biome is a pioneering study for this purpose in this region and points out important microorganisms that have potential for enzymatic production in biological biomass depolymerization, resulting in biotechnologically useful products.