Event Title

Exploring the Role of Fertilization oliar Nutrient Concentrations of a Tropical Rainforest

Advisor(s)

Silvia Alvarez-Clare, The Morton Arboretum

Ashley Wojciechowski, The Morton Arboretum and North Central College

Location

Room A113

Start Date

26-4-2019 10:45 AM

End Date

26-4-2019 11:00 AM

Abstract

Tropical rainforests are responsible for 30% of the total carbon dioxide exchange between the biosphere and atmosphere and store large amounts of carbon as biomass. Soil nutrient availability is an important regulator of forest carbon cycles by influencing tree growth and leaf nutrient concentrations. In this project, we studied how nitrogen (N) and phosphorus (P) added as fertilizer to the soils impact nutrient concentrations in the leaves of the most abundant tree (Pentaclethra macroloba) and tree palm (Socratea exorrhiza) seedlings as well as three other understory plants (palm Geonoma congesta, forb Calathea lasiostachya, and fern Polybotrya caudata) in a lowland tropical rainforest of Costa Rica. We collected 180 plants at EARTH University’s EFFEX experiment, where forest plots have been continuously fertilized with N, P, NP, or kept as controls for 11 years and then used an elemental analyzer and ash digestion to measure the leaf nutrients. We found that the N treatment increased N foliar concentrations but NP treatment did not increase N showing luxury consumption of N. Foliar N:P ratios show NP colimitation. This research will advance our understanding of the role that nutrients play on the carbon cycle in tropical forests. Using this knowledge we will be better equipped to predict changes caused by global change.

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Apr 26th, 10:45 AM Apr 26th, 11:00 AM

Exploring the Role of Fertilization oliar Nutrient Concentrations of a Tropical Rainforest

Room A113

Tropical rainforests are responsible for 30% of the total carbon dioxide exchange between the biosphere and atmosphere and store large amounts of carbon as biomass. Soil nutrient availability is an important regulator of forest carbon cycles by influencing tree growth and leaf nutrient concentrations. In this project, we studied how nitrogen (N) and phosphorus (P) added as fertilizer to the soils impact nutrient concentrations in the leaves of the most abundant tree (Pentaclethra macroloba) and tree palm (Socratea exorrhiza) seedlings as well as three other understory plants (palm Geonoma congesta, forb Calathea lasiostachya, and fern Polybotrya caudata) in a lowland tropical rainforest of Costa Rica. We collected 180 plants at EARTH University’s EFFEX experiment, where forest plots have been continuously fertilized with N, P, NP, or kept as controls for 11 years and then used an elemental analyzer and ash digestion to measure the leaf nutrients. We found that the N treatment increased N foliar concentrations but NP treatment did not increase N showing luxury consumption of N. Foliar N:P ratios show NP colimitation. This research will advance our understanding of the role that nutrients play on the carbon cycle in tropical forests. Using this knowledge we will be better equipped to predict changes caused by global change.