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“Nutrient cycling and CO2 emission in the semi-arid
region” |
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One of the oldest research projects developed at Fazenda Tamanduá is
that concerning “Nutrient cycling and CO2 emission in the semi-arid
region”, which has been proceeding without interruption since 2004.
Jacob Silva Souto and Patrícia Carneiro Souto, who are now both
professors, are continuing this work, a sum of scientific data
unprecedented in the sertão, and an incredible contribution to
the knowledge of this poorly studied eco-system. |
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A
study is being carried out in Fazenda Tamanduá’s Private Nature
Reserve, in the municipality of Santa Terezinha (PB), in order to
achieve a better understanding of the behavior of the caatinga
– a kind of vegetation typical to this region – in respect of nutrient
cycles and CO2 emission.
The Nature Reserve has an area of 381.6 ha. and is within the
semi-arid region of North-East Brazil, where low water supply and high
temperatures are predominant most of the year. |
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When
the study is concluded, it will become the doctoral thesis of Forestry
Engineer Patrícia Carneiro Souto. She is a CAPES scholar in the
Agronomy PhD Program at Paraíba Federal University, working under the
supervision of Professors Dr. Jacob Silva Souto and Dr. José Romilson
Paes de Miranda, of the Forestry Engineering Department, Patos (Paraíba)
Campus, Campina Grande Federal University (UFCG), with the
participation of CNPq scholarship students of Scientific Initiation
and volunteers from the Forestry Engineering Graduation Course.
It is
important to stress that work on the nutrient cycles in the
caatinga region is rare. It is common knowledge that the
absorption and return of nutrients, in annual terms, may
be greater in tropical forests than in other types of
vegetation. |
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These
nutrients (nitrogen, phosphorus, potassium, calcium,
magnesium, sulfur, etc.), originating mostly from dead
biomass (leaves, branches, flowers, fruit, trunks, dead
roots, etc.), are attacked by organisms from the soil.
The
knowledge of all this structure may be used as an
indicator of the way the system works, providing
information on the degree of deterioration or recovery
of a particular area.
The
execution of this work, which has the unlimited support of the owner
of Fazenda Tamanduá, Dr. Pierre Landolt, is of fundamental importance
for the region, considering that, for a period of two years, the
amount of leaves, branches, bark, flowers, fruit and other materials
that collect in gathering boxes distributed in the area will be
studied on a monthly basis, as well as the decomposition of this
material by organisms in the soil, using nylon bags containing litter
from the study area. |
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Forestry Engineer Patrícia Carneiro Souto
collecting
leaves, branches,
flowers, fruit, trunks, dead roots, etc |
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In
the same experimental area, data relating to CO2 emission
from the soil are also collected monthly, during the daytime and
nighttime periods. This information will be extremely important in
order to acquire better knowledge of the caatinga region, with
regard to carbon sequestration. |
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In order to quantify the CO2
rising from the soil, a solution of
KOH 0.5 N in glass containers, covered by plastic buckets,
is used |
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In order to quantify the CO2 rising from the soil, a
solution of KOH 0.5 N in glass
containers, covered by plastic
buckets, is used.
After a 12-hour period, from 7:00 a.m. to 7:00
p.m., and again from 7:00 p.m. to 7:00 a.m., corresponding to the
day and night periods, respectively, the samples are collected in
the field, hermetically sealed and then transported to the Soil
and Water Laboratory of the Forestry Engineering Department of the UFCG, to be titrated with a solution of HCl 0.1 N in order to
quantify the CO2 retained in each sample.
At the same time as the litter is collected, samples of soil are
taken in order to determine micro-organisms (bacteria and fungi)
and, using steel volumetric rings, soil + litter is collected in
order to extract and count the mesofauna (acarids, springtails,
beetles and other organisms up to 1.0 mm in length). |
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Tropi-Dry Research |
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Researchers from the Federal Universities of Pernambuco (UFPE) and
Campina Grande (UFCG) are carrying out research at Fazenda
Tamanduá in order to study the ecology and regeneration of the
caatinga bush country.
The research is part of a broad project of the Collaborative
Research Network (CRN) called “TROPI-DRY” (Tropical Dry Forests).
The TROPI-DRY network includes researchers from Canada, the United
States, Mexico, Cuba, Costa Rica, Venezuela and Brazil, who will
work on tropical deciduous forest ecosystems located in these 5
latter countries, over the next 5 years.
In Brazil, two areas will be studied, one in the North of the
State of Minas Gerais and another at Fazenda Tamanduá, in the
municipality of Santa Terezinha – State of Paraíba. |
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Participants
and collaborators of the Tropi-Dry Project in full activity
at Fazenda Tamanduá - PB. From left to right: Prof. Jacob Souto,
Patrícia Moura, Prof. Everardo Sampaio, Joab Araújo, Awesley,
Karina and Prof. Patrícia Souto. |
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A continuous and systematic effort will be made in order to
understand, integrate and compare information on tropical dry forests
in the Americas, at 3 basic levels: |
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in the context of
ecological and biological conservation;
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in the context of the
use of the soil and changes in the vegetation occurring in those
ecosystems that have been subject to intensive occupation;
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in the context of the
development of local and national policies that may contribute to
the preservation of these ecosystems.
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Another important contribution will come from information on the location,
size and state of forest areas in which a threat to biodiversity may be
identified in de-forestation frontiers, for later evaluation and for the
implementation of solutions to this problem. Thus, the challenge is to
create a scientific framework capable of facilitating the maintenance of
healthy ecosystems, and, at the same time, recognize and improve the
quality of human life in the regions where dry forests occur in the
Americas.
At Fazenda Tamanduá, four areas with vegetation at different stages of
regeneration were selected, in which 12 plots of 1800 sq. m. each were
marked out. These plots range from pasture areas, through caatinga areas
with about eight to ten years of regeneration, then other caatinga areas
about twenty years old, and lastly, a preserved caatinga area over 50
years old.
In these areas, several activities are being carried out to enhance
understanding of the ecological processes involved in the regeneration of
the caatinga. In the first place, a phyto-sociological survey of the areas
is being done, in order to characterize the evolution of vegetable species
diversity and the caatinga structure in the course of sequential stages.
In these same areas, studies are also being carried out for the evaluation
of both soil biology and the cycling of nutrients, carbon and water. It is
important to stress that studies of this kind usually face a great deal of
difficulty in finding preserved caatinga areas that will allow the
research to be carried out.
The research in question will generate knowledge that will help to
orientate conservationist actions aiming at the sustainable development of
the natural ecosystems and also the agro-ecosystems in the semi-arid
region. |
