Plotting a future for Amazonian canga vegetation in a campo rupestre context

Abstract

In order to establish effective conservation strategy, drivers of local and regional patterns of biodiversity need to be understood. The composition of local biodiversity is dependent on a number of factors including evolution and redistribution of lineages through dispersal and environmental heterogeneity. Brazilian canga is characterised by a ferrugineous substrate, found both in the Iron Quadrangle of Minas Gerais and in the Carajás mountains in Amazonia. Canga is one of several specialised habitat types comprising Brazilian campo rupestre , a montane vegetation found within or adjacent to several major Brazilian bioregions, including the Atlantic Forest and Amazonia, with exceptionally high levels of diversity and endemism arising from both history of dispersal and environmental variation. In order to inform biodiversity conservation for canga , and more broadly for campo rupestre , we performed floristic and phylogenetic analyses investigating affinities between 28 sites on different substrates ( canga and quartzite) and geographic locations (Carajás, Pará [Amazonia]; Cadeia do Espinhaço, Minas Gerais; Chapada Diamantina, Bahia). Through analysis of 11204 occurrences of 4705 species of angiosperms, we found that Amazonian Carajás canga plant communities formed a cohesive group, distinct from species assemblages found in Eastern Brazil (Minas Gerais, Bahia), either on canga or quartzite. The phylogenetic megatree of species across all sites investigated shows associations between certain clades and Amazonian canga , with few shared species between the Amazonian Carajás and Eastern Brazil sites, while the floristic comparison shows high levels of heterogeneity between sites. The need for reserves for Amazonian Carajás canga has been recognized and addressed by the creation of a national park. However, current sampling does not provide sufficient reassurance that the canga areas now benefitting from full legal protection adequately represent the regional canga flora.

Combining genotype, phenotype, and environmental data to delineate site‐adjusted provenance strategies for ecological restoration

“…Although mixing individuals from different management units could result in outbreeding depression (Hufford & Mazer, 2003; Weeks et al., 2011)⁠, the risk is probably marginal for these study species, which are widely distributed across the continent (Dutra & Morim, 2015; Queiroz, 2015)⁠. Moreover, environmental conditions and plant communities show remarkable similarities across the Carajás Mineral Province when compared to other campo rupestre formations (Zappi et al., 2019)⁠. Such a regional admixture provenancing approach (Bucharova et al., 2019)⁠ would represent a significant improvement over introducing exotic species, which are currently being used in mine reclamation programmes due to the availability of seeds in large quantities and their ability to quickly colonize mine environments to prevent soil erosion (D'Antonio & Meyerson, 2002; Gastauer et al., 2019; Silva et al., 2018)⁠.…”

Seed Functional Traits Provide Support for Ecological Restoration and ex situ Conservation in the Threatened Amazon Ironstone Outcrop Flora

“…Ironstone outcrops represent harsh environments under the influence of strong abiotic filters that include high soil temperatures, shallow, metal-rich and nutrient-impoverished soils that restricts establishment by many generalist species, but create conditions for the survival of edaphic specialists (Rajakaruna, 2018;Zappi et al, 2019;Corlett and Tomlinson, 2020). Mining activities pose significant threats for these edaphic endemics, while create opportunities for seed-based restoration strategies.…”

“…Mining activities pose significant threats to canga endemics (Zappi et al, 2019), and have negative repercussions that extend to areas far beyond operational lease boundaries (Sonter et al, 2017). Extensive land-use changes result from an increasing global demand for steel (Sonter et al, 2014) suggest an uncertain future for canga endemics (Fernandes et al, 2018).…”

“…Our focus here was on the endemic and threatened flora growing on ironstone outcrops (banded iron formations locally known as cangas) which are extensively explored for open cast iron mining (Viana et al, 2016;Mota et al, 2018). Owing to a high degree of endemism and newly discovered species (Viana et al, 2016;Mota et al, 2018;Giulietti et al, 2019), knowledge gaps on the ecology of ironstone endemics need to be filled to implement appropriate conservation and management programs (Zappi et al, 2019). Giulietti et al (2019) concluded that 38 of the 856 species registered by Mota et al (2018) are edaphic endemics restricted from the cangas.…”

Plant species on Amazonian canga habitats of Serra Arqueada: the contribution of an isolated outcrop to the floristic knowledge of the Carajás region, Pará, Brazil

“…Recent studies of the flora and vegetation growing on canga in Brazil have provided insights into their richness and endemism (Jacobi et al 2007;Viana et al 2016;Carmo et al 2018;Mota et al 2018;Giulietti et al 2019;Zappi et al 2019).…”