Litterfall and Nutrient Returns in Isolated Stands of <i>Persea gratissima</i> (Avocado Pear) in the Rainforest Zone of Southern Nigeria

Abstract

This study assesses litterfall and nutrient returns to the soil in isolated stands of Persea gratissima in the rainforest zone of southern Nigeria. The study examined litter production, the concentrations of nutrients in litterfall, the returns of nutrient elements to the soil via litterfall, the relationship between litter production nutrient returns via litterfall, and determined the seasonal variations in litter production and the returns of nutrient elements via litterfall respectively. Data collection was on litterfall which was collected from February 2010 -January 2011. Data collected were statistically analyzed using the SPSS 15.0 version. Average litter production was 60.23 g/m²/yr and 77.31 g/m²/yr for the Persea gratissima and adjoining rainforest. Results of the Independent Samples T-Test revealed that there are significant differences between Persea gratissima and adjoining rainforest in litter production and returns of nutrient elements via litterfall. Except for Nitrogen, the concentrations of nutrient elements were similar. Results of Pearson's bivariate analyses showed that significant positive relationships exist between litter production and nutrients returned to the soil through litterfall at the 5% levels. However, litter production and the returns of nutrient elements vary with the seasons of the year, but the trend in the seasonal patterns of nutrient returns from Persea gratissima and adjoining rainforest is similar for K, Ca, Na and Mg. Persea gratissima return nutrients to the soil through litterfall, therefore its production should be encouraged to help in improving the soil nutrient status in rainforest areas.

Canopy dynamics in a tropical Atlantic forest mosaic in southeastern Brazil

“…Leaf litter production is directly related to climatic conditions (Mason 1980), and they can vary in importance on temporal and spatial scales according to the ecosystem under consideration (Lavelle et al 1993). In general, leaf litter production is negatively correlated with low temperatures, rainfall, and humidity and positively correlated with the maximum temperature-resulting in a marked seasonality (Austin and Vitousek 2000;Pragasan and Parthasarathy 2005;Bhat et al 2009;Ndakara 2011) and increased leaf litter production in the dry season (Thomas et al 2014). Other studies undertaken in Brazilian seasonal semideciduous forests have corroborated these observations, with consistent reports of the highest leaf biomass production the middle to the end of the dry season (Morellato 1992;Pagano and Durigan 2001;Werneck et al 2001;Arato et al 2003;Pinto et al 2008).…”

Aboveground carbon stocks, woody and litter productivity along an elevational gradient in the Rwenzori Mountains, Uganda

“…The increase in litter productivity in dry months has been attributed to leaf abscission, a mechanism to regulate transpiration rates in plants and omit high water stress (Ndakara, 2011; Valentini et al, 2008). In addition, in the wet tropics, the shedding of senescent leaves occasionally coincides with the production of new leaves (Descheemaeker et al, 2006; Zalamea & González, 2008), hypothesized a mechanism to evade the high humidity periods with higher pathogen, fungal and insect herbivory pressure on tender leaves (Givnish, 1999).…”

“…Ultimately, in such ecosystems, the total seasonal pattern is the result of the overlapping of seasonal patterns of individual groups leading to the spreading‐out of litter productivity peaks. This can lead to the dampening of the intensity of seasonal variability (Ndakara, 2011; Zalamea & González, 2008; Zhang et al, 2014). Additionally, lack of a significant water limitation may also contribute to low seasonality in litter productivity.…”

A gridded dataset of a leaf-age-dependent leaf area index seasonality product over tropical and subtropical evergreen broadleaved forests

“…Litterfall is closely related to the seasonal dynamics of old leaves (i.e., LAI old ; Yang et al, 2021). Previous analyses indicated that, in general, a sharp decrease in LAI old corresponded to a peak in litterfall (Pastorello et al, 2020;Midoko Iponga et al, 2019;Ndakara, 2011;Barlow et al, 2007;Dantas and Phillipson, 1989). Based on this causal relationship between litterfall and LAI old , we compared the time of seasonal litterfall peak with the time of abrupt drops in LAI old to indirectly evaluate the simulated LAI old seasonality.…”