The climatic variables showed a high variation in the Brazilian territory (Fig. 6). The mean air temperature ranged from 13.1 ° C to 28 ° C with the highest values in the north of the country and the lowest in the south (Fig. 6A). The state of Pará, located in the northern region, obtained the highest values of air temperature, with an average of 27.5 (0.49) ° C. The states of Santa Catarina and Rio Grande do Sul stood out as the coldest in the country, with an average of 18.0 ° C. The locations of Belém - PA and Bom Jardim da Serra - SC were the warmest and coldest in the country, respectively, as also observed by Alvares et al. (2013).
Precipitation varied widely between regions of the country (Fig. 6C). The annual rainfall in Brazil was 1467 (± 46.91) mm, with the states of Amapá and Amazonas having the highest volumes, with averages of 2999.78 (± 152.15) and 2665.03 (± 67.44 ) mm, respectively. On the other hand, the states of Rio Grande do Norte and Paraíba had the lowest average volumes of only 800.86 (± 59.83) and 852.62 (± 52.78) mm values similar to that found by Medeiros et al. (2019) and Santos et al. (2019). The potential evapotranspiration (PET), the average for Brazil was 980.09 (± 22.32) mm (Fig. 6B), with the highest values being concentrated in the South and North regions of the country, and the states with the highest averages were the Rio Grande do Sul and Amazonas, with 1297.20 (16.74) and 1258.04 (± 14.64) mm, respectively. While the states of Rio Grande do Norte and Ceará showed the lowest PET values, with 670.90 (± 31.17) and 680.31 (± 39.19) mm.
The altitude spatialization demonstrated its variability across the Brazilian territory (Fig. 6D). The altitude in Brazil varied from 0 to 1601 m, with the extremes of the country having altitudes below 200 m. On the other hand, the southeast regions showed an average of 645.8 m, locating the highest municipalities in the country, Campos do Jordão - SP, Itamonte - MG, and Marmelópolis - MG, with altitudes of 1601, 1592, and 1570 m. Locations with high altitudes generally have a temperature below the regional average, considering that with the increase in altitude, the volume in the atmosphere is reduced, making it difficult to stir air molecules, thus having an inversely proportional relationship between temperature and altitude as observed by Lancaster (1980).
Brazil has shown a great variation for biotemperature, with an average of 22.9 (± 1.83) ° C (Fig. 7). Biotemperature decreases in the north-south direction of Brazil, and the northern region was almost entirely classified in the biotemperature class greater than 24 ° C and less than or equal to 26 ° C. A small part of northeastern Pará, southeastern Amapá, and northern Maranhão were the regions classified in the highest biotemperature class (greater than 26 ° C). The states with the highest values of biotemperature were Pará, Maranhão, and Amapá, with 27.48 (± 0.94) ° C, 27.28 (± 0.82) ° C and 27.09 (± 1.16) ° C, respectively. On the other hand, the states of Rio Grande do Sul, Santa Catarina, and Paraná, the states of the southern region of the country, had the lowest biotemperatures, 17.96 (± 2.80) ° C, 18.02 (± 3.30) ° C and 19.08 (± 2.80) ° C, respectively. In these colder regions, some crops have great representativeness, such as English potatoes, grapes, and apples (IBGE 2018).
Basal biotemperature ranged from 16 ° C to 28.6 ° C, with an average of 24.9 ° C, with higher values concentrated in the northern region of the country, while the lowest values were in the southern region (Fig. 7B). The states with the highest and lowest biotemperatures were Pará and Rio Grande do Sul, with an average of 28.1 (0.2) ° C and 20.0 (1) ° C, respectively. The ratio between PET and P, after spatialization, showed that the most humid regions of the country are located in the north, on the other hand, the northeast stands out with the driest region (Fig. 7C).
Brazil demonstrated 3 altitudinal belts, basal, premontane, and low montane (Fig. 8A). In the country, 66.24% were found to belong to the basal elevation belts, concentrating a large part of the North, Northeast, and Midwest regions. The premontano belts corresponded to 29.95% of the national territory, going from the central region to the south of the country. The mountainous low belts only 3.79% of the territory of Brazil, located mainly in the South and regions of high altitudes in the Southeast. These regions are problematic for the cultivation of some crops such as soy, maize, and sugarcane, however, it is the regions with the greatest aptitude for the cultivation of seasoned fruits such as apple, pear, plum, and grapevine (Pio et al. 2018).
Three latitudinal regions were found in Brazil, Tropical, Subtropical, and Hot temperate (Fig. 8B). The most representative latitudinal region was the tropical region, with 90.13% of the total area, which is found in the North, Midwest, Southeast, and Northeast regions. With 9.51%, the subtropical latitudinal region was the second most found in Brazil, present mainly in the coastal states of the Southeast region and the south region, results according to Derguy et al. (2019) on the border between the state of Paraná and Argentina. The warm temperate latitudinal region represented 0.35% of Brazil's surface, being restricted to the extreme south of the State of Rio Grande do Sul.
With the increase in temperature, there was a reduction in the subtropical and temperate latitudinal region in the south and southeast of the country and expansion of the tropical region in other locations. For the altitudinal belts, there was an expansion of the basal belt due to the increase in the average biotemperature of the region. The precipitation variation scenarios remained identical to the current scenario for the altitudinal belts (Fig. 8A) and latitudinal regions (Fig. 8B).
Regarding the humidity provinces, Brazil presented only four types, super-humid, humid and sub-humid, and semi-arid (Fig. 8C). Most of the country was classified as wet, encompassing 58.16% of the Brazilian territory, concentrating the South, Midwest, Southeast, and part of the other regions, providing good agricultural development in much of the country (Tweed et al. 2018). The super humid province was registered in 32.93% of the Brazilian territory with the highest concentration in the northern region and one occurrence in the southern region. The provinces and sub-humid and semi-arid were less significant, representing around 8.66% and 0.22%, respectively concentrated in the northern region of Minas Gerais and the northeast region of the country. The northern region was the region that most demonstrated the super humid province, mainly in the states of Amapá, Rondônia, and Roraima, which were classified as super humid, due to those with higher levels of precipitation. Part of the northeast region, mainly the interior, concentrated the only areas of the sub-humid and semi-arid province, with emphasis on the state of Bahia, which has 62.22% of its territory belonging to the sub-humid province and 2.79% to the semi-arid province. Bahia is a major producer of soybean, maize, and cotton (IBGE 2018).
In the 1.5 ° C and 3 ° C temperature rise scenarios there was a predominance of super humid provinces in the north of Amazonas and Amapá, semi-arid and sub-humid provinces in the northeast region. With the 30% reduction in rainfall, there is a predominance of arid, semi-arid, and sub-humid provinces in the northeast region and humid provinces in the rest of the country. The 30% increase in rainfall is predominant in the super humid provinces in the northern and southern regions, and the humid and sub-humid provinces in the northeastern region.
Brazil presented for the current scenario (S1) a total of 15 approximate life zones (Fig. 9A) and 30 life zones including transition regions (Fig. 9B) in the current scenario, 5 less compared to the work of Tres et al. (2020), in which he presented 35 life zones. Of the 15 approximate life zones (Fig. 9A) there is a predominance of the 60.57% basal tropical rainforest zones (Table 1) with the highest concentration in the north of the Midwest region, most of the North and Northeast regions including the coast. E Premontane tropical rainforest in 17.30% (Table 1) of the Brazilian territory with predominance in the south of the Midwest region, and most of the Southeast region, and the State of Acre. Considering the transition zones (Fig. 9B), there is a predominance of the life zones in the basal tropical rainforest in 29.67% of the Brazilian territory with the highest occurrence in the north of Mato Grosso, Rondônia, and the extreme north of the northern region in the state of Amapá, and the zone due Rainforest basal humid corresponding to 15.45% located in the center of the State of Mato Grosso and east of the North region.
The Midwest, Northeast, and Northeast regions of the Southeast showed tropical climates, classified as Basal tropical rainforest and Premontane tropical rainforest (Fig. 9A) corresponding to the main life zones in the country, concentrating 60.57% and 17, 30% (Table 1) of the Brazilian territory respectively. These regions are major producers of Soy, Corn, and Coffee (IBGE 2018). The South region presented subtropical climates where the most present areas of life were the humid premontane subtropical forest and the low humid subtropical montane forest, which represent 51.71% and 26.50% of the region, respectively.
The capital of Brazil, Brasília, presented the zone of life, humid premontane rainforest. Other capitals such as São Paulo and Rio de Janeiro were classified as humid premontane subtropical forests. The warmest and coldest locations in the country, Belém - PA and Bom Jardim - SC da Serra, were classified as Basal humid tropical forest and Low humid subtropical montane forest, respectively. The two municipalities are located at the extremes of the country, to the north and south, in addition to having a large difference in altitude, demonstrating the impact of latitude and altitude on air temperature (Reynolds et al. 2018; Sunday et al. 2019).
The sensitivity analysis demonstrated the impact of rainfall and air temperature on the Holdridge (1967) classification system and can be seen in Fig. 10 (S2 S3 S4 S5). The increase of 1.5°C and 3.0°C in the average air temperature caused a variation between the number of life zones to 18 and 11, respectively. It also reduced the area of the humid basal subtropical forest living area to 48.92% and 48.95% (Table 1) and an increase in the area of the dry basal tropical forest area, surpassing that which was the largest in the current scenario, representing only 21.96% and 34.58%, (Table 1) respectively.
To scenario S4 (30% reduction in average precipitation), there were 16 life zones, with an emphasis on the life zones Dry basal tropical forest, with 49.87% (Table 1) of all Brazilian territory in the regions to the north of the Midwest, most of the North region encompassing the entire state of Rondônia and the western and coastal regions of the Northeast. The wetland premontane tropical forest with 13.13% (Table 1) had the highest occurrence in the west of the North region, South of the Midwest region, and west of Minas Gerais. S4 has a higher percentage in dry life zones compared to S1, totaling 65.57% of the surface, whereas in S1 these life zones have low representation.
The scenario with an increase of 30% in average precipitation (S5) showed great variation to the scenario S1 with 19 life zones, 4 is more than the current scenario (S1) (Fig. 10A). The most prevalent area of life in this scenario was a humid basal tropical forest with 50.12% of all Brazilian territory (Table 1), concentrated in a large part of the northern region and the northern part of the Midwest. The wetland Premontano tropical rainforest was the second largest in territorial extension with 10.09%, mainly to the west of the North region, southeast of the Midwest region, south of Minas Gerais, and little occurrence in the central region of Paraná and Litoral de São Paulo, Rio de Janeiro and Paraná.
In all the scenarios evaluated, the tropical life zones were concentrated in the Amazon biome in the north of the country, Cerrado, Caatinga, Pantanal, and Atlantic forest in the Midwest, North, Southeast, and Northeast regions, whereas the subtropical life zones are located in a great part of the Atlantic Forest biomes in a strip that extends from the south of the country to the coast of the Southeast region, the hot temperate life zones occurred in the pampa biome in the extreme south of the country with a small strip in the south of the State of Rio Grande do Sul (Fig. 11).
Table 1
The proportion of occurrences of Holdridge life zones (1967) for each scenario of climate change in the Midwest.
LIFE ZONES
|
(CURRENT)
|
S2
|
S3
|
S4
|
S5
|
Subtropical basal dry forest
|
-
|
0.00151
|
0.000713
|
-
|
-
|
Subtropical basal moist forest
|
-
|
-
|
0.000247
|
-
|
-
|
Subtropical lower montane dry forest
|
-
|
-
|
-
|
0.008221
|
-
|
Subtropical lower montane moist forest
|
3.000557
|
0.207612
|
0.108458
|
3.117392
|
0.259522
|
Subtropical lower montane wet forest
|
0.124963
|
0.389767
|
-
|
-
|
2.865908
|
Subtropical premontane dry forest
|
0.047651
|
0.00203
|
-
|
2.148529
|
0.025002
|
Subtropical premontane moist forest
|
5.754455
|
3.782774
|
3.134764
|
4.23937
|
2.667315
|
Subtropical premontane wet forest
|
0.58654
|
0.71189
|
0.705652
|
-
|
3.69572
|
Tropical basal dry forest
|
1.376475
|
21.96326
|
34.58323
|
49.87651
|
9.570618
|
Tropical basal moist forest
|
60.57437
|
48.92394
|
48.9537
|
11.09982
|
50.12662
|
Tropical basal thorn woodland
|
-
|
0.515753
|
-
|
0.057943
|
-
|
Tropical basal very dry forest
|
4.374661
|
8.337951
|
4.806903
|
5.290974
|
3.045076
|
Tropical basal wet forest
|
-
|
-
|
-
|
-
|
3.58313
|
Tropical lower montane dry forest
|
-
|
-
|
-
|
0.002012
|
-
|
Tropical lower montane moist forest
|
0.267617
|
0.147788
|
0.015253
|
0.265419
|
0.053773
|
Tropical lower montane wet forest
|
-
|
0.041119
|
-
|
-
|
0.213774
|
Tropical premontane desert scrub
|
-
|
-
|
-
|
0.03421
|
-
|
Tropical premontane dry forest
|
4.680224
|
1.922695
|
0.443228
|
8.213867
|
4.059556
|
Tropical premontane moist forest
|
17.30891
|
12.92914
|
6.985021
|
13.13398
|
8.557078
|
Tropical premontane rain forest
|
-
|
-
|
-
|
-
|
0.631127
|
Tropical premontane thorn woodland
|
0.323096
|
0.006781
|
-
|
2.158418
|
0.200982
|
Tropical premontane wet forest
|
1.227129
|
0.098611
|
0.262841
|
-
|
10.09184
|
Warm temperate lower montane moist forest
|
0.352374
|
0.016975
|
-
|
0.35236
|
0.218477
|
Warm temperate lower montane wet forest
|
-
|
-
|
-
|
-
|
0.133514
|
Warm temperate premontane moist forest
|
0.000975
|
0.0004
|
-
|
0.000975
|
-
|
Warm temperate premontane wet forest
|
-
|
-
|
-
|
-
|
0.000975
|