Author(s)

Deodato do Nascimento Aquino¹, Eunice Maia de Andrade^2*, Andréa Dardes de Almeida Castanho³, Lécio Resende Pereira Júnior², Helba Araújo de Queiroz Palácio⁴

¹Instituto Nacional de Colonização e Reforma Agrária, Fortaleza, Brazil.
²Department of Agricultural Engineering, Federal University of Ceará, Fortaleza, Brazil.
³Woods Hole Research Center, Falmouth, USA.
⁴Federal Institute of Education, Science and Technology, Iguatu, Brazil.

The aim of this study was to quantify the dynamics of herbaceous biomass and fine root productivity, and their relationship to stocks of carbon and nitrogen, in the Vertisols of two adjacent watersheds of a seasonally dry tropical forest (SDTF) under two different types of ground cover. The two watersheds are located in the county of Iguatu in the State of Ceará, Brazil. The control watershed of 2.1 ha, has been under regeneration for 35 years (RC₃₅), while the second watershed (1.1 ha) was subjected to thinning for a period of 5 years (TC₅). The sampled variables were herbaceous shoot biomass, fine roots, gravimetric moisture, the isotope δ¹³C (‰), total soil carbon (TSC) and total nitrogen (TN) in the 0 - 20, 20 - 40 and 40 - 60 cm layers, between April 2013 and March 2014. To quantify herbaceous shoot biomass, samples were taken monthly. For TSC and TN, the campaigns were held every two months. The data underwent analysis of means and were compared by t-test (p < 0.05). Under TC₅, there was an increase in the stocks of TSC and TN of 151 and 137% respectively in the 40 - 60 cm layer, in relation to RC₃₅. The implementation of thinning in a SDFT is seen as a management alternative to be considered in sustainability programs in the semi-arid region, contributing to maximising the production of herbaceous forage for feeding large and small ruminants, and for bee pasture, in addition to increasing the stock of carbon in the soil of SDFT and reducing global warming.

Carbon Sequestration, Dry Forests, Isotope δ¹³C, Herbaceous Plants

do Nascimento Aquino, D., de Andrade, E.M., de Almeida Castanho, A.D., Pereira Júnior, L.R. and de Queiroz Palácio, H.A. (2017) Belowground Carbon and Nitrogen on a Thinned and Un-Thinned Seasonally Dry Tropical Forest. American Journal of Plant Sciences, 8, 2083-2100. doi: 10.4236/ajps.2017.89140.