Due to the importance of agriculture in the North and Central-West Region, distribution sites
of the species Podocnemis expansa, the objective was to study if the impacts caused by the
advancement of agriculture and livestock can affect the environment to the point of interfering
with the optimal temperature of performance of these animals. With this, the performance
curve of this species was elaborated, in order to understand the optimum temperature for its
performance, comparing individuals of natural environment and commercial production. In
addition, the analysis of land use and occupation in the Araguaia Basin was conducted
between 1985 and 2017 to show the progress of the agricultural sector. An analysis was also
made of the variations in flow and precipitation levels in the Alto Araguaia Basin, in the same
time cut, in which it was possible to identify possible changes in the flow caused by the
agricultural practice. The ecophysiological study was carried out in the municipality of Lagoa
da Confusão - OT in the period of ebbing season of 2018. Animals were collected from
natural environment and captivity, these individuals were submitted to low and high
temperatures aiming to find the minimum and maximum critical, respectively, in addition to
be submitted to 6 test batteries at 3 different temperatures to compose the locomotor
performance curve. Each battery consisted of timing the swim time on a 2 meter course. With
the value of the minimum and maximum critical temperature it was possible to compose the
graph along with these results. For the analysis of land use and occupation, maps of the years
of 1985, 1996, 2006, and 2017 of the Araguaia River Basin were elaborated. The maps were
obtained through the MapBiomas Project, processed and treated in Qgis software. For the
analysis of flow and rainfall, rainwater and rainfall data were collected from 24 and 34
stations, respectively, on the HidroWeb platform of the National Water Agency, inserted in
the Alto Araguaia Basin, in order to obtain the time series decomposition, detecting the
effects of seasonality and trends in flow and precipitation variation. The data were corrected
using Amelia package and tested by means of mixed effects linear models (LMMs) the ratio
of river flow with the percentage area occupied by agriculture in the ANA level 4 ottobacias.
The result obtained with regard to the locomotor performance of the P. expansa turtle
indicates a significant difference (P <0.001) in the locomotor performance curve between
individuals from both environments. Commercial turtle turtles showed inferior performance
compared to wild-type animals, however, it was observed that captive animals had a better
performance at higher temperatures. Concerning the use and occupation of the soil in the
Araguaia River Basin, an increase of over 8 million ha was observed. There was a significant
difference between the flow and precipitation levels over the years, and a significant negative
relation between the area occupied by agriculture and the average flow of the Alto Araguaia
Basin. From the results obtained, it was known that the advance of the area occupied by
agriculture affects the environment of survival of P. expansa and that the species presents a
thermoforming behavior, indicating that a severe increase in temperature could lead the
species to extinction, since it does not have thermoregulatory behavior.
|
