There is increasing interest in the restoration/regeneration of degraded tropical habitats yet the potential role of natural regenerators remains unclear. We test the hypothesis that the richness and functional diversity of terrestrial mammals differs between forest regrowth stages. We quantified the richness and functional diversity of eight terrestrial mammal seed-disperser species across a forest regrowth gradient in the eastern Brazilian Amazon. We installed camera-traps in 15 sites within small-holder properties with forest regrowth stage classified into three groups, with five sites each of: late second-regrowth forest, early second-regrowth forest and abandoned pasture. Species richness and functional dispersion from the regrowth sites were compared with 15 paired forest control sites. Multi model selection showed that regrowth class was more important for explaining patterns in richness and functional diversity than other variables from three non-mutually exclusive hypotheses: hunting (distance to house, distance to river, distance to town, small holder residence), land cover (% forest cover within 50 meters, 1 kilometer and 5 kilometers) and land use (regrowth class, time since last use). Differences in functional diversity were most strongly explained by a loss of body mass. We found that diversity in regrowth sites could be similar to control sites even in some early-second regrowth areas. This finding suggests that when surrounded by large intact forest areas the richness and functional diversity close to human small-holdings can return to pre-degradation values. Yet we also found a significant reduction in richness and functional diversity in more intensely degraded pasture sites. This reduction in richness and functional diversity may limit the potential for regeneration and increase costs for ecological regeneration and restoration actions around more intense regrowth areas.

Highlights The occurrence, density and biomass of adult arborescent palms were measured in a National Forest in the eastern Brazilian Amazon. Commercially important arborescent palms were rare. Density and biomass were related to hydrographic and topographic variables. Subsidised agroforestry practices are required to facilitate the commercialization of palm NTFPs. Published as:Norris, D., Chuma, V.J.U.R., Arevalo-Sandi, A.R., Paredes, O.S.L. and Peres, C.A., 2016. Too rare for non-timber resource harvest? Meso-scale composition and distribution of arborescent palms in an Amazonian sustainable-use forest. Forest Ecology and Management, 377,. oleracea, an economically important species. The presence, biomass, and density of palms were uncorrelated with geographic distances among plots. The hydrographic model significantly explained variation in palm presence and biomass, whereas density was only explained by the topographic model. Our findings indicate that arborescent palms are currently too rare to be efficiently harvested as NTFPs in the study area. Yet, comparisons with published estimates suggest that there is significant potential for agroforestry to facilitate the commercialization of palm NTFPs for community based extractive activities.

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Mammal groups have a vast variety of habitats, which include aquatic, aerial, arboreal, and terrestrial. For terrestrial habitats, camera traps are used as a common technique to record mammals and other vertebrates and have been recently utilized to observe arboreal animals as well. Here, we compare the difference in mammal diversity between floor and canopy strata and evaluate the use of camera trapping in a lowland forest in central Amazon. We installed nine paired camera traps, one in the canopy stratum and other in the floor stratum, in the Alto Cuieiras Biological Reserve (Brazilian Amazon). With a sampling effort of 720 camera-days, we recorded 30 mammal species: nine in canopy strata, 14 in floor strata, and seven in scansorial strata (sharing both strata). On the forest floor, the species with the greatest abundance was Myoprocta acouchy; in the canopy, Isothrix paguros had the greatest abundance; and among the scansorial species, Proechymis sp. was the most abundant. Our results show the differences in mammal diversity between floor and canopy strata; canopy strata contained more small and frugivorous mammals. Although we obtained a relatively low sampling effort with the camera-trap method compared with other studies utilizing different techniques, our results were especially similar to those of previous studies that worked with canopy and floor strata. Thus, camera trap can be very effective for recording short periods of time, and this method is less physically exhaustive and expensive for researchers to study vertical strata.