Zornia subsessilis (Zornia subsessilis)

Mohamed bin Zayed Species project number 220528913

Conservation of Zornia subsessilis (Leguminosae: Papilionoideae: Dalbergieae), endemic species from Espinhaço Range of Minas Gerais, Brazil

The comprehensive study undertaken to assess the status and conservation implications of Zornia subsessilis in the state of Minas Gerais, southeastern Brazil, has yielded critical insights into the ecological dynamics of the species and the challenges it faces. As Brazil holds the global record for biodiversity, the Cerrado phytogeographic domain, particularly the Campo rupestre vegetation within the Espinhaço Range, emerges as a hotspot of diversity but simultaneously faces significant threats.

The Southern Espinhaço Range, specifically the Serra do Cabral region, stands out for its distinctive vegetation, hosting many endemic species, including Zornia subsessilis. However, the area faces severe threats, mainly from anthropogenic activities such as arson, expansion of agricultural lands, and industrial activities such as coal-fired power plants.

In the course of this research initiative, the acquisition of 12 additional unique hotspots of Zornia subsessilis provided a more nuanced understanding of its distribution and ecological requirements. Prior to the expeditions of this project, knowledge of its distribution was based on only four occurrence points.

During the expeditions, it was also possible to observe a remarkable adaptive feature of post-fire regeneration mediated by xylopodium, but its critically endangered status still persists. The habitat of Zornia subsessilis is particularly vulnerable to habitat loss due to agricultural and livestock expansion.

Furthermore, the limited dispersal abilities of Zornia subsessilis became evident during expeditions to regions surrounding its central occurrence, where no collection records were obtained. This scarcity is attributed to factors such as the species' minimal seed production—indicated by the fruit with only three articles—and its exclusive occurrence at elevations of 1,300 meters or more. The geographic isolation of Serra do Cabral from the rest of the Espinhaço range further restricts the species' dispersal to other areas.

Following the fieldwork, modeling analyses conducted with the expanded dataset revealed alarming predictions for the future of the species. In optimistic, intermediate and critical scenarios, analyses consistently predict a 100% loss of the species’ range. This dire prognosis underscores the urgency of conservation efforts and highlights the precarious situation of Zornia subsessilis.

Serra do Cabral State Park, designed as a conservation area, faces the dual challenges of arson and encroaching agricultural activities. This is particularly disconcerting given the significant proportion of endemic species, including Zornia subsessilis, within the park. Consequently, the study’s findings underscore the immediate need for targeted conservation actions to protect not only the unique biodiversity of the Serra do Cabral region, but also the long-term survival of Zornia subsessilis. These results contribute valuable insights to the broader discourse on biodiversity conservation, emphasizing the imperative of proactive measures to mitigate anthropogenic threats and preserve critical habitats amidst increasing environmental challenges.