Theme 08: Grazing Ecology
Description
Forty forage species samples were collected in September 1999, including grass, sedges, forbs, shrubs and trees. Seven hand-compounded mixtures of known botanical composition and dry weight were prepared. Five slides of each mixture were made and 20 frequency observations were recorded per slide. Two procedures were used to determine percent composition on a dry weight basis and their values were converted to correct the proportion of the unidentifiable fragments amongst species. Estimated and actual values differed significantly (P < 0.05) in 31.7%, 34.1%, 12.2% and 12.2% of the species for frequency addition (FA), density convertion (DC), frequency addition converted (FAC) and density convertion converted (DCC), respectively. The average similarity values between estimated and observed mixture were 90.2, 86.0, 94.2 and 93.3 for FA, DC, FAC and DCC, respectively. In conclusion, food habits by microscopic analysis may be described using any of the procedures tested because they rank important forage species for herbivores.
Included in
Test of a Conversion Equation to Increase the Accuracy of Microhistological Analysis of Herbivore Diets in the Pantanal
Forty forage species samples were collected in September 1999, including grass, sedges, forbs, shrubs and trees. Seven hand-compounded mixtures of known botanical composition and dry weight were prepared. Five slides of each mixture were made and 20 frequency observations were recorded per slide. Two procedures were used to determine percent composition on a dry weight basis and their values were converted to correct the proportion of the unidentifiable fragments amongst species. Estimated and actual values differed significantly (P < 0.05) in 31.7%, 34.1%, 12.2% and 12.2% of the species for frequency addition (FA), density convertion (DC), frequency addition converted (FAC) and density convertion converted (DCC), respectively. The average similarity values between estimated and observed mixture were 90.2, 86.0, 94.2 and 93.3 for FA, DC, FAC and DCC, respectively. In conclusion, food habits by microscopic analysis may be described using any of the procedures tested because they rank important forage species for herbivores.
