A decade of monitoring shows the dynamics of a conserved Atlantic tropical forest

Characterised with its immense biodiversity and high levels of endemism, the Atlantic Tropical Forest has been facing serious anthropogenic threats over the last several decades, demanding for such activities and their effects to be closely studied and monitored as part of the forest dynamics.

Cattle farming, expanding agricultural land areas and mining have reduced the Atlantic Forest to many small patches of vegetation. As a result, important ecosystem services, such as carbon stock, are steadily diminishing as the biomass decreases.

Brazilian researchers, led by Dr. Écio Souza Diniz, Federal University of Viçosa, spent a decade monitoring a semi-deciduous forest located in an ecological park in Southeast Brazil. Their observations are published in the open access Biodiversity Data Journal.

The team surveyed two stands within the forest to present variations in the structure and diversity of the plants over time, along with their dynamics, including mortality and establishment rates. They based their findings on the most abundant tree species occurring within each stand.

At the forest stands, the most abundant and important species for biomass accumulation are concluded to be trees larger than 20 cm in diameter, which characterise advanced successional stage within the forest.

“It is fundamental that opportunities to monitor conserved sites of the Atlantic Forest are taken, so that studies about their dynamics are conducted in order to better understand how they work,” note the scientists.

“The information from such surveys could improve the knowledge about the dynamics at anthropised and fragmented sites compared with protected areas.”

In order to encourage further research into the composition, diversity and structure of the Atlantic Forest over time and the subsequent contributions to the preservation of this threatened ecosystem, the authors made their data publicly available. The datasets, including species occurrences, are now openly accessible via the Global Biodiversity Information Facility(GBIF) and the biodiversity informatics data standard Darwin Core.

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Original source:

Diniz ES, Carvalho W, Santos R, Gastauer M, Garcia P, Fontes M, Coelho P, Moreira A, Menino G, Oliveira-Filho A (2017) Long-term monitoring of diversity and structure of two stands of an Atlantic Tropical Forest. Biodiversity Data Journal 5: e13564. https://doi.org/10.3897/BDJ.5.e13564

Effects of soil and drainage on the savanna vegetation in the northern Brazilian Amazonia

It is a well-known fact that environmental factors such as soil texture and drainage determine to a very large degree the vegetation appearance, richness and composition at any site. However, there has been little research on how these variables influence the flora in the marvellous savannas – large open areas characterised by a complex and unique network of natural resources and life forms.

Consequently, a Brazilian research team, led by Dr. Maria Aparecida de Moura Araújo, Universidade Federal de Roraima, investigated the hydro-edaphic conditions in the savanna areas in the northern Brazilian Amazonia. Their study, complete with an openly available and ready for re-use dataset, is published in the open access Biodiversity Data Journal.  

Image 1_Annonaceae_Xylopia aromatica_treeIn the course of the Program for Biodiversity Research, managed by the Brazilian government, the scientists sampled 20 permanent plots in two savanna areas in the state of Roraima, located in the northern of the Brazilian Amazon. As a result, the team reports a total of 128 plant species classified into 34 families from three savanna habitats with different levels of hydro-edaphic restrictions.

Amongst the various factors playing a role in the soil characteristics of the area, are the tectonic events and past climatic fluctuations which have occurred in the most recent period of the Cenozoic era. Paleo, as well as modern fires are likely to be other culprits for the specific conditions.

In conclusion, the authors suggest that the most restrictive savanna habitats – the wet grasslands, represent the home to less structurally complex plants, compared to the well-drained shrubby localities.

“The present study highlights the environmental heterogeneity and the biological importance of Roraima’s savanna regarding the conservation of natural resources from the Amazon,” say the scientists.

Image 2_Convolvulaceae_Merremia aturensis_herb“In addition, it points out the need for greater investment in floristic inventories associated with greater diversification of sites, since this entire ecosystem has been rapidly modified by agribusiness.”

Licensed under a Creative Commons License (CC-BY 4.0) and available in a Darwin Core Archive DwC-A format; the complete dataset is openly available via the Global Biodiversity Information Facility (GBIF).

 

Original source:
Araújo M, Rocha A, Miranda I, Barbosa R (2017) Hydro-edaphic conditions defining richness and species composition in savanna areas of the northern Brazilian Amazonia. Biodiversity Data Journal 5: e13829. https://doi.org/10.3897/BDJ.5.e13829