Jalpan de Serra - Geography and Environment

Geography and Environment

The municipality is located in the north of the state of Querétaro. The municipality borders the municipality of Pinal de Amoles, San Joaquín, Landa de Matamoros and Arroyo Seco, with the state of San Luis Potosí to the north and east and the state of Hidalgo on the south. It is the second largest municipality with an extension of 1185km2.

The mountains of the municipality are the southern part of the Sierra Madre Oriental, as part of a sub province called the Huasteco Karst. These mountains began as sea bed 140 million years ago with coral reefs then layers of sand. This sea bed eventually became limestone and other types of rock as the mountains rose from the sea, starting 65 million years ago. This rising of the sea bed has also created the mountains which range in heights from 700 masl to 1500 masl. Between these, there are semi flat area called “intermountain valleys,” many of which contain the municipality’s principle roadways. Its altitudes vary between 200 meters above sea level in the canyon of the Santa María River to 2,440 masl at the peak of the Sierra Grande, located in the south of the territory.

Because of the sedimentary nature of the area’s rock, a phenomenon called karstification is prominent, where limestone dissolves slowly and forms pit caves and deep canyons such as in the Tancoyol valley, San Juan de los Durán, Valle Verde and Zoyapilca. Much of the erosion occurs during the rainy season in arroyos, creating canyons that can be as deep as 600 meters.

There are three main river basins in the municipality, Santa María, Extoraz, Moctezuma, which are all part of the Pánuco River basin, with over 96% of the rainfall directed to the Santa María River. The Jalpan River passes through the municipal seat, and contains the Jalpan Dam, which stores water for the various communities of the municipality. This river unites with the Del Real arroyo then empties into the Santa María. The Santa María and Extoraz rivers form the borders of the municipality with the states of San Luis Potosí and Hidalgo respectively. The Extoraz River separates it from San Joaquín.

The topography is the main determinant of climate within the municipality. The east of the territory has the highest altitudes, with an average rainfall of about 1500 mm per year, with some areas getting as much as 2000. It is one of the wetter zones of the Sierra Gorda because the area inclines toward the Gulf of Mexico, allowing moist air to reach it. Average temperatures range from 11 to 15C. Lower altitudes are present in the north in Valle Verde and the upper part of Santa María River Canyon. From here on south the area is drier with rainfall totals ranging from 800 to 500 mm per year. This makes up the majority of the municipality and the largest expanse of semi moist hot lands in the Sierra Gorda. However in the canyons of the Santa María, Moctezuma and Extoraz rivers, the climate is classified as hot and semi dry.

Flora is extremely varied due to the wide range of altitudes and climate conditions in the municipality. Over much of the territory, there are lowland deciduous rainforest with species such as : palo de arco (Lysiloma microphylla), tepehuaje (Lysiloma acapulcensis), guayabillo (Psidium sartorianum), jopoy (Esenbeckia berlandieri), chacas (Bursera lancifolia), aquiches (Guazuma ulmifolia), laurel (Phoebe tampicensis), órganos (Neobauxbamia polylopha), as well as various species of orchids and Bromeliaceae. Most of the vegetation loses its leaves during the dry season and regains them during the rainy season. In some canyon areas, leaf loss in the dry season is less.

The east side of the municipality is dominated by temperate ecosystems, especially in the higher altitudes. These areas are dominated by oaks, junipers, pines, white cedars and other conifers, with some other species such as palm trees and strawberry trees. At the foot of the mountains on the west, there is scrub brush. The northeast of the municipality around the communities of San Juan de los Durán, Valle Verde and La Cercada are dominated by mesophile forests, with has a very high level of biodiversity including a number in danger of extinction.

Wildlife is as diverse as the flora, with species types ranging from those adapted to near arctic to tropical conditions. Six feline species including the jaguar and ocelot are found here, as well as two species of deer and the peccary. Black bear have been sighted as well as porcupines and anteaters. In addition, there are about 300 species of birds, both year-round and migratory species and a wide variety of reptiles and amphibians.