Litter decomposition in a remnant of Atlantic Rain Forest and bamboo dominance

Abstract

Aim of study: We compared the decomposition rate of the accumulated litter, the stock, and the return of nutrients to the soil, between an area dominated by bamboos in the understory and an area where this dominance does not occur.
 Area of study: Fontes do Ipiranga State Park, an Urban Fragment of Atlantic Forest at the Municipality of São Paulo, Southeastern Brazil.
 Materials and methods: The decomposition rates were measured over one year (0, 3, 6, 9, and 12 months), avoiding litter addition through nylon nets over the soil. The collected material was separated into the following fractions: bamboo leaves and branches (bamboo material); other leaves and branches (other material); very decomposed material not identifiable (unidentifiable). The content of macro (N, P, K, Ca, Mg, and S) and micronutrients (B, Cu, Fe, Mn, and Zn) were determined.
 Main results: The litter accumulated was significantly higher in the mature area than in the bamboo area. The decomposition rates did not differ significantly between the two areas. Except for K and Mn, the concentrations of macro and micronutrients were equal to or greater in the mature forest.
 Research highlights: Unlike reported in other areas, there is no greater litter accumulation in the bamboo-dominated understory nor a slower decomposition rate. The nutrient content is lower in the bamboo-dominated disturbed area.

Impacts of bamboo dominance and die‐off on seedling dynamics in a tropical secondary forest (Brazil)

“…Bamboo super‐dominance is a response to different levels of disturbance that changes forest dynamics and structure as well as altering community interactions (Buziquia et al., 2019; Campanello et al., 2007; Rother et al., 2016, 2018). In general, studies have showed that changes in biotic and abiotic conditions after bamboo die‐off (such as decreases in invertebrate abundance, higher light penetration, higher temperatures and less moisture) can boost opportunities for seed overstorey germination and seedling growth (Abe et al., 2005; Austin & Marchesini, 2011; Caccia et al., 2015; Giordano et al., 2009; Takahashi et al., 2007; Vieira et al., 2022). This positively affects tree seedling dynamics and richness and promotes successful forest regeneration and stabilization (Budke et al., 2010; Capellesso et al., 2016, 2022; Marchesini et al., 2009).…”

“…Our study was carried out in the Fontes do Ipiranga State Park (hereafter PEFI), a tropical forest fragment of Atlantic Forest located in southeastern Brazil (23°38′08″–23°40′18″ S and 46°36′48″–46°38′00″ W; 759–837 m a.s.l.). The predominant soil types in the area are Inceptisols and Oxisols (Vieira et al., 2022). The regional climate is classified as Cwa in the Köppen system (1948), with an average annual temperature of 18.7°C and total annual rainfall of 1412.3 mm (data from 1933 to 2017, IAG–Instituto Astronomico e Geofisico, 2017).…”

“…Woody bamboos are perennial plants that propagate vegetatively with persistent underground rhizomes, displaying fast‐growing rates after which they exhibit a massive synchronized and widespread flowering with abundant seed production followed by death (Janzen, 1976; McClure, 1993). This subsequent die‐off promotes conspicuous changes in abiotic and biotic conditions that can exert both positive and negative effects on tree seedling dynamics and composition (Budke et al., 2010; Caccia et al., 2015; Giordano et al., 2009; Holz & Veblen, 2006; Marchesini et al., 2009) by increasing light availability to forest understory, reducing invertebrate abundance (herbivory; Abe et al., 2005; Caccia et al., 2015) and/or by altering nutrient cycling (Austin & Marchesini, 2011; Marchesini et al., 2009; Takahashi et al., 2007; Vieira et al., 2022). The change of initial conditions after the bamboo die‐off (Budke et al., 2010; Montti, Campanello, Gatti, et al., 2011; Montti, Campanello, & Goldstein, 2011; Santos et al., 2012) may be followed, after longer periods, by tree regeneration and stabilization of forest structure (Capellesso et al., 2016, 2022), or by a fast bamboo recolonization, interfering with the forest regeneration process (Lacerda & Kellermann, 2019; Montti, Campanello, & Goldstein, 2011).…”