Agriculture can be an ally to biodiversity conservation
January 22, 2014
By Karina Toledo
Agência FAPESP – In addition to producing food, services and energy, agricultural pastures have a secondary but equally important role, a role that should be strengthened: the conservation of biological diversity.
Professor Luciano Martins Verdade, of the Center for Nuclear Energy in Agriculture at Universidade de São Paulo (CENA/USP), discussed this topic during the last meeting of the 2013 BIOTA-FAPESP Education Conference Cycle, organized by the FAPESP Research Program for the Characterization, Conservation and Sustainable Use of Biodiversity (BIOTA-FAPESP). Held on November 21, 2013 at FAPESP’s headquarters, the theme was “Biodiversity in Urban and Rural Anthropic Environments.”
“The production sector and conservationists are at odds. But production must take into consideration the importance of preserving biodiversity, which is already there and could be even richer. Conversely, environmental initiatives linked to conservation should consider the role that agriculture plays in civilization. Seven billion people could not simply go back to being gatherers. The role of agriculture is too important to allow the luxury of being against it,” argued Verdade.
The USP professor, who is also a member of the BIOTA-FAPESP coordination team, has just concluded a Thematic Project in which he studied the historical change in the agricultural landscape from the 1850s – when the first private properties emerged – and the consequences for the current standards of biological diversity.
“The history of this land structuring determined the structure of the landscape. Large landholdings were split, and cities emerged as result of the trade from these properties. This is all reflected in the current structure of agricultural landscapes, which have a particular biological diversity,” said Verdade.
According to Verdade, pastures for cattle raising are currently predominant in São Paulo State, followed by sugarcane plantations for ethanol production and eucalyptus forests for paper and pulp production.
“There are more remnants of forests on these properties than in the State Conservation Units (UCs), and when we began the project, the agricultural landscapes were not even considered habitats by environmentalists. They said that there were no animals to be preserved there, but anyone who has been to a sugarcane field or a eucalyptus grove know this was not true,” he said.
According to the results of the Thematic Project, São Paulo agricultural landscapes have 27 different species of medium-sized and large mammals, 202 species of birds, 18 reptiles, 31 amphibians and 55 fish.
“The majority are generalist species or, rather, those that use the landscape as a whole and are not restricted only to fragments of the native vegetation,” explained Verdade.
Still, according to data from the Thematic Project, the eucalyptus plantations are less welcoming to birds than are the pastures, but they are more inviting to mammals and amphibians. Frequently present in eucalyptus groves, for example, are the giant anteater (Myrmecophaga tridactyla) and the cougar (Puma concolor). In the pastures, it is possible to observe the presence of the red-legged seriema or crested cariama (Cariama cristata) and the toco toucan (Ramphastos toco), for example.
“Mid-sized and large mammals such as the crab-eating fox (Cerdocyon thous) are less abundant in pastures but common in sugarcane fields. Rodents and their predators are more frequent in sugarcane fields than in fragments of native vegetation,” said Verdade.
“One of the main conclusions of the project is that this diversity cannot be seen at a single time point. It is not the fruit of today’s spatial structure but rather of the historical process that formed it. The standards of biological diversity change as land use changes. And land use is changing in São Paulo State,” affirmed Verdade.
According to Verdade, there is currently heavy socioeconomic pressure favoring the replacement of low-productivity pastures with sugarcane fields and silviculture. This change would have a major impact on the physical landscape and the species that inhabit it.
“There will be, for example, greater use of fertilizers, agricultural inputs and other chemical products, which are practically nonexistent in pastures. It is impossible to know whether the change will be good or bad. We will begin to have the capacity to forecast these scenarios when we understand these historical, socioeconomic, cultural, evolutionary and ecotoxicological processes that determine the standards of biological diversity,” explained Verdade.
In the USP Professor’s assessment, in addition to expanding the knowledge of the processes that determine standards of biological diversity, individuals involved in conservation must invest in technological innovation.
“With the expansion of the conceptual basis and with technological innovation, we will be able to help in the decision-making process for governance. In fact, we will be able to attribute to agricultural landscapes a multifunctional mission, retaining their role in producing domesticated species while adding a secondary (and not less relevant) mission, which is to promote the conservation of wildlife species,” he added.
The diversity of fauna in urban anthropic environments was the topic of a lecture by Elisabeth Höfhling, a faculty member at the USP Biosciences Institute (IB/USP). According to the researcher, insects represent the most diverse group of fauna in cities, but there are also many species of birds, spiders, reptiles, mammals, amphibians and even marsupials.
The vegetal diversity of each region is, according to Höfhling, the most important determinant of the diversity of urban fauna. However, the availability of food, shelter, water and construction materials for nests are also important factors.
Among the factors that contribute to the decline in animal species in urban areas are chemical pollution of air, water and vegetation, along with sound pollution (which causes hearing loss, stress and alterations in sound communication), and artificial lighting (which affects biological cycles associated with day and night).
Among the species introduced by humans that have become common in urban environments are the house sparrow (Passer domesticus), the rock dove (Columba livia) and the common waxbill (Estrilda astrild).
According to the survey coordinated by Höfhling and published in the book Aves no Campus [Birds on the Campus], there are roughly 161 species of birds at the USP campus in the West End of São Paulo.
The diversity of flora in urban environments was the topic of a lecture given by Roseli Buzanelli Torres, of the Campinas Agronomy Institute (IAC). The researcher stressed the importance of tree planting in cities to increase air humidity levels and to reduce the temperature, the wind speed and heavy rainfall, thereby conserving asphalt, retaining pollutant particles and improving the psychological well-being of residents.
“It is estimated that trees with dense crowns can retain up to 98% of solar radiation; and trees with thin crowns, between 60% and 80%. Additionally, they can retain up to 60% of the water in the first two hours of rainfall. All this reduces the risk of flooding and facilitates the storage of rainfall in ground water,” he affirmed.
At the end of the event, BIOTA-FAPESP Coordinator Carlos Alfredo Joly announced a new cycle of educational conferences in 2014. The purpose of the initiative is to contribute to improving science teaching, primarily in high schools.
Among the topics are “Ecosystem Services – concept and values” (2/20), “Biodiversity and Pollination” (3/20), “Biodiversity and Protection and water resources” (4/24), “Biodiversity and Climate Change and Biodiversity” (5/22) and “Biodiversity and Nutrition Cycling” (6/26).