Original paper
Cattle decreases plant species diversity in protected humid temperate savanna
Batista, William B.; Mochi, Lucía S.; Biganzoli, Fernando
Phytocoenologia Band 48 Heft 3 (2018), p. 283 - 295
65 references
published: Aug 17, 2018
published online: May 16, 2018
manuscript accepted: Feb 4, 2018
manuscript revision received: Jan 19, 2018
manuscript revision requested: Dec 29, 2017
manuscript received: Oct 20, 2017
ArtNo. ESP024004803001, Price: 29.00 €
Abstract
Question: Is domestic cattle an appropriate surrogate for fire in a protected humid temperate savanna? Study area: El Palmar Grande de Colón (31º52´ S, 58º17´ W), Argentina. Methods: We surveyed dense Butia yatay palm savannas in two neighboring protected areas, El Palmar National Park (EPNP), under cattle exclusion since 1970 with sporadic burning; and La Aurora Wildlife Refuge (LAWR), under moderate cattle density, and not burnt since 1997. In each area, we randomly selected ten dense savanna stands, established 500 m² plots and undertook floristic survey in spring and summer to produce exhaustive plant-species lists. We statistically compared the two samples in terms of: local and global diversities; compositional heterogeneity among stands; mean similarity to a historical record from the area; overall species composition; and abundance and numbers of species with different growth habits and origins. Results: Differences between our samples are clear-cut. Savannas at EPNP have significantly increased local and global species richness and exhibit decreased similarities with the historical record. They have a novel understory, with significantly increased abundances and species numbers of fire-resistant grassland shrubs and fire-sensitive trees, and a groundcover with significantly increased richness of subshrub and perennial graminoid species. Savannas at LAWR have virtually no woody understory, and exhibit a groundcover dominated by an impoverished suite of perennial grasses, with significantly increased abundances and numbers of annual and of exotic species. Conclusions: Our results suggest that large-scale, long-term cattle exclusion and sporadic fires have resulted in changes in the structure and composition of the savanna vegetation leading to increased plant species diversity. Apparently, conservation of these humid savannas in protected areas requires periodic fire, while domestic cattle are a poor alternative for maintaining their plant species diversity. Abbreviations: EPNP = El Palmar National Park; LAWR = La Aurora Wildlife Refuge Taxonomic reference: Anton & Zuloaga (2012) Submitted: 20 October 2017; first decision: 29 December 2017; accepted: 04 February 2018
Keywords
Campos region • cattle • fire • grazing • National Park • humid savanna • protected area • species diversity