Deposição de Fitomassa em Formações Secundárias na Floresta Atlântica do Paraná

Abstract

RESUMOEste trabalho objetivou avaliar a deposição de serapilheira em três formações secundárias com diferentes idades na Floresta Ombrófila Densa Submontana no Paraná. A serapilheira anual produzida foi avaliada mensalmente por 25 coletores (1 m 2 ) distribuídos sistematicamente em cada formação secundária (1 ha) e separada em frações (ramos, órgãos reprodutivos, miscelânea e folhas). Não houve diferença significativa entre as formações quanto à deposição anual de serapilheira, provavelmente devido às semelhanças entre elas com relação à estrutura da vegetação e às condições meteorológicas. A maior deposição de serapilheira total e frações ocorreu nos meses com maiores temperatura e precipitação. A fração folhas foi a mais representativa na serapilheira total em todas as formações, sendo que na floresta secundária menos desenvolvida (FS-1) houve contribuição de um menor número de espécies, quando comparada com a floresta secundária intermediária (FS-2) e a floresta secundária mais desenvolvida (FS-3).Palavras-chave: Floresta Ombrófila Densa, serapilheira, sucessão florestal. Litterfall in Secondary Forests in the Brazilian Atlantic Forest of Paraná State ABSTRACTThis research is focused in evaluating the litterfall in secondary forests of Dense Ombrophilous Submontane Forest in the coast of Paraná state. The annual litterfall produced was evaluated monthly by 25 collectors (1 m 2 ), systematically distributed in each secondary formation (1 ha) and separated into fractions (twigs, reproductive organs, remains, and leaves). There was no significant difference between the secondary formations on the annual litterfall, probably due to the similarities they both have with respect to the structure of vegetation and meteorological conditions. The highest deposition of total litter and fractions occurred in the months of highest temperature and rainfall. The fraction leaves were the most representative of total litterfall in all formations, with the less evolved secondary forests (FS-1) contributing with fewer number of species, when compared with the intermediate and more evolved secondary forests (FS-2) and (FS-3), respectively.

Litter production in a natural stand of Brazil nut trees (Bertholletia excelsa Bonpl.)

“…Meteorological factors are frequently included in research on litterfall, principally air temperature and precipitation (Bianchin et al, 2016;Chave et al, 2010;Ferreira et al, 2015;Santos Neto et al, 2015;Zhang et al, 2014) and also evapotranspiration (Wagner et al, 2016). Borchert et al (2015) related that insolation is also a relevant climatic factor for litter production.…”

Seasonality influence the nutrient content of litter fall in secondary forest in the Amazonian

“…The nutrients Cu and Mn showed the highest concentrations during the dry season. Bianchin et al (2016), the absence of a period with water deficit, together with the low occurrence of deciduous species in these environments, allows for greater deposition in higher precipitation and temperature, thus interfering with the concentration of nutrients.…”

Litterfall Production at Different Successional Stages in a Tropical Rain Forest in Southern Brazil

“…The references found in the specific literature with respect to annual amount of litterfall in Ombrophilous Dense Forest vary according to forest formation, ranging from 5.4 to 12.2 Mg ha -1 yr -1 in Submontane Ombrophilous Dense Forest (ARAÚJO et al, 2006;DICKOW et al, 2012;BIANCHIN et al, 2016;SLOBODA et al, 2017), from 4.9 to 5.6 Mg ha -1 yr -1 in Montane (GOMES et al, 2010;FREIRE et al, 2014), and from 6.1 to 7.1 Mg ha -1 yr -1 in Mixed Ombrophilous Forest (FIGUEIREDO FILHO et al, 2005;ANTONELI;THOMAZ, 2012;SANQUETTA et al, 2016). In studies carried out in old-grown forests in the north coast of Parana state, litterfall was estimated at 8.4 Mg ha -1 yr -1 (SLOBODA et al, 2017), and in advanced secondary forests in the southern region of Santa Catarina at 7.5 to 10.55 Mg ha -1 yr -1 (CITADINI-ZANETTE, 1995;SANTOS, 1997;ROSSO, 2011), being close to that sampled in AR in the present study, with 8.13 Mg ha -1 yr -1 .…”