Ecological implications of twentieth century reforestation programs for the urban forests of São Paulo, Brazil: a study based on litterfall and nutrient cycling

Ecological Processes

Plínio Barbosa de Camargo¹  Karina Gonçalves da Silva¹  Raffaele Lafortezza²  Ana Paula Branco do Nascimento³  Marcelo Ferreira Barbosa⁴  Eduardo Pereira Cabral Gomes⁵  Edgar Fernando de Luca⁶  Maurício Lamano Ferreira⁷  Ulisses Bezerra França⁸ 

[1] Centro de Energia Nuclear na Agricultura (CENA/USP), University of São Paulo, Piracicaba, SP, Brazil;Department of Agricultural and Environmental Sciences, University of Bari Aldo Moro, Bari, Italy;Department of Geography, The University of Hong Kong, Centennial Campus, Pokfulam Road, Hong Kong, Hong Kong;Department of Civil Engineering, São Judas Tadeu University, São Paulo, SP, Brazil;Department of Health, Faculty of Biological Science, University Nove de Julho (UNINOVE), São Paulo, SP, Brazil;Institute of Botany (IBT/SP), São Paulo, SP, Brazil;Institute of Forestry (IF/SP), São Paulo, SP, Brazil;Master’s Program in Health Promotion, Adventist University of São Paulo, São Paulo, SP, Brazil;Master’s Program in Geoenvironmental Analysis, University of Guarulhos, Guarulhos, SP, Brazil;Prefeitura da cidade de São Paulo (Secretaria do Verde e Meio Ambiente), São Paulo, SP, Brazil;

关键词: Tropical forest;    Exotic species;    Nutrient dynamics;    Ecosystem functioning;   

DOI  :  10.1186/s13717-021-00292-7

来源: Springer

【 摘 要 】

The focus of this study was to investigate the wide use of Eucalyptus spp., an exotic plant with high allelopathic ability, in the reforestation programs of urban parks in São Paulo City, Brazil, over the last century. To understand the implications of using Eucalyptus spp. in the city’s parks, this study aimed to compare nutrient cycling and litter decomposition between a mixed composition of litter (i.e., native and exotic species) and the litter of a single species (i.e., Eucalyptus). To accomplish this, newly deciduous leaves were collected from two native and two exotic species that are commonly used in the afforestation of São Paulo as well as from Eucalyptus spp. The mixed composition of litter yielded a higher dry mass loss and return of macro- and micronutrients to the forest floor. The decomposition constant (k) values were 0.00322 and 0.00207 g g−1 day−1 for the mixed composition and Eucalyptus spp., respectively. The time required for decomposition of 50 and 95% of deciduous material was 215 and 931 days, respectively, and for the mixed litterfall 334 and 1449 days, respectively, for Eucalyptus spp. Therefore, the mixed litter exhibited greater dry mass loss and nutrient cycling in an urban forest of São Paulo City, since dry mass losses as well as speed and amount of nutrients returned to the forest floor were relatively higher compared to Eucalyptus spp. Nutrient cycling via Eucalyptus spp. litter was less efficient than mixed composition of litter, demonstrating that reforestation programs carried out in the twentieth century using only one species may have had little success. The results of this work emphasize the fact that in urban reforestation programs the City of São Paulo must consider the environmental and biogeographic characteristics of the species employed and use high levels of biodiversity, since the city lies in a megadiverse biome.

【 授权许可】

CC BY