Variation in aboveground biomass and necromass of two invasive species in the Atlantic rainforest, southeast Brazil

Abstract

RESUMO -(Variação da biomassa e necromassa aérea de duas espécies invasoras na Floresta Atlântica, sudeste do Brasil). Este trabalho descreve a variação da biomassa e necromassa aérea, e da produção primária líquida (NAGPP) de duas espécies invasoras Panicum maximum Jacquin (Poaceae) e Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae) em duas áreas da Reserva Biológica de Poço das Antas, no sudeste brasileiro. As duas espécies eram mono-dominantes nestas áreas, ambas localizadas na matriz entre fragmentos florestais. A matéria orgânica foi amostrada mensalmente durante dois anos, separada em biomassa e necromassa e a produção aérea primária líquida (NAGPP) foi calculada. Houve variação intra-sazonal bem marcada, para ambas as espécies; Pa. maximum geralmente apresentou os maiores valores para biomassa, necromassa, massa total e NAGPP (NAGPP, Pa. maximum = 3953 g m -2 ano -1 , Pt. arachnoideum = 2667 g m -2 ano -1 ). A NAGPP não variou entre as duas estações de crescimento para Pa. maximum, porém estas diferenças foram acentuadas para Pt. arachnoideum (2% comparados aos 44% de variação em relação a média). A segunda estação de crescimento foi mais seca e Pa. maximum produziu maior quantidade de necromassa do que na primeira estação de crescimento; Pteridium mostrou pouca variação sazonal de biomassa, mas uma maior produtividade na segunda estação de crescimento. Pteridium arachnoideum é aparentemente mais sensível ao clima, especialmente em relação à pluviosidade. Palavras-chave: fogo, Panicum maximum, plantas invasoras, Pteridium arachnoideumABSTRACT -(Variation in aboveground biomass and necromass of two invasive species in the Atlantic Rain Forest, Southeast Brazil). This paper describes the variation of the above-ground biomass, necromass, and net above-ground primary production (NAGPP) of two weed species, Panicum maximum Jacquin (Poaceae) and Pteridium arachnoideum (Kaulf.) Maxon. (Dennstaedtiaceae), at two sites in the Poço das Antas Biological Reserve, southeast Brazil. Both species form mono-dominant stands in the matrix surrounding forest fragments. The organic matter was sampled monthly from each site, separated into biomass and necromass, and net above-ground primary production (NAGPP) was calculated. There was marked intra-seasonal fluctuation for both species; Pa. maximum generally had the largest values for necromass, total mass and NAGPP (NAGPP, Pa. maximum = 3953 g.m -2 .y -1 , Pt. arachnoideum = 2667 g.m -2 .y -1 ). NAGPP did not vary between the two growth periods for Pa. maximum, but marked differences were found for Pt. arachnoideum (2% compared to 44% variation around the mean). The second growth year was drier and Pa. maximum produced much greater necromass in that year; Pt. arachnoideum showed little variation in biomass but much greater productivity in the drier second season. Pteridium arachnoideum appears to be more sensitive to climate, and especially rainfall.

Invasion impact by Pteridium arachnoideum (Kaulf.) Maxon (Dennstaedtiaceae) on a neotropical savanna

“…elliottii, studied by and Schizolobium parahyba, analyzed by Abreu et al 2014) or by bracken in other situations (Ghorbani et al 2006;Mack et al 2000;Portela et al 2009). In the study region, the very severe frosts that were able to damage the native Cerrado vegetation (Brando & Durigan 2004) may also have reduced the Pteridium arachnoideum population (Watt 1954).…”

“…Although bracken ferns of the Pteridium genus were already part of plant communities prior to human settlement and agriculture, they are currently regarded as a problem species in various regions of Brazil (Matos & Pivello 2009;Portela et al 2009) and other parts of the world (Marrs et al 1997;Marrs & Watt 2006). Characterized by large fronds and rapidly expanding rhizomes, brackens reduce the establishment of native vegetation (Marrs & Watt 2006), and act as an important ecological filter in the assembly of invaded communities (Matos & Belinato 2010).…”

“…Characterized by large fronds and rapidly expanding rhizomes, brackens reduce the establishment of native vegetation (Marrs & Watt 2006), and act as an important ecological filter in the assembly of invaded communities (Matos & Belinato 2010). Species of Pteridium produce large quantities of dry biomass, increasing the frequency and intensity of wildfires (Ghorbani et al 2006;Portela et al 2009;Silva & Matos 2006), and can also alter the soil seed bank and hinder the establishment of native species due to allelopatic compounds (Gliessman & Müller 1978).…”

“…Invasions by bracken have been the subject of several recent studies in Brazil, which have shown the negative impacts of bracken species on native ecosystems (Matos & Belinato 2010;Matos & Pivello 2009;Portela et al 2009;Salgado 2012), on economic activities (Furlan et al 2014), and on human health (Hojo-Souza et al 2010). However, one study demonstrated that bracken populations could diminish over time and possibly succumb to forest succession (Pinheiro & Durigan 2009).…”

Modelagem multi-hierárquica de distribuição potencial e seleção de filtros ambientais de espécies invasoras no Estado de São Paulo

“…Registros de invasão: Apesar de considerada cosmopolita, o gênero é reportado como invasor na região do Andes, no sudeste do Equador (Beck et al, 2008), na Inglaterra e no México (Colleen, 2011). No Brasil existem estudos descrevendo o gênero como invasor na Floresta Estacional Semidecidual (Silva, Matos & Belinato, 2010;Portela et al, 2009;Silva & Matos, 2006) e no Cerrado (Matos, Xavier, Tiberio, & Marrs, 2014;Miatto, Silva, Matos, & Marrs, 2011;Pinheiro & Durigan, 2009 Origem: Nativa do Himalaia e Sul da China.…”