Some ecological aspects of Myrick Marsh with an emphasis on animal populations

Abstract

The objectives of this study were to gain a comprehensive knowledge of the dynamics of the marsh with an emphasis on mammal populations. Attempts were made to study the dynamics on a biomass basis as they related to marsh habitats. Field work was conducted from February 1974 to January 1975. The 515 acres of the Myrick Marsh study area have a great complexity of marshland habitats including ponds, cattail marsh, and a great expansive area covered by reed canary grass. Gross environmental characteristics were determined for each of the six study units involved. Plant production in kilograms/hectare(kg/ha) was estimated by use of the clipping technique and it was concluded that Phalaris arundaceae (L.) and Typha latifolia (L.) constituted approximately 70% of the marsh vegetation. By utilizing known methods the relative densities of insect populations which inhabited smartweed, cattail and reed canary grass dominated areas were examined. It was found that the reed canary grass supported the highest overall populations; with Diptera being the most abundant insect order. Invertebrate populations were compared for the litter, soil and standing vegetation between a smartweed and a reed canary grass area. Mites and springtails were the most dominant organisms found in the litter and soil, while slugs and spiders were the most abundant in the standing vegetation. One hundred and sixty-eight small mammals were caught by use of snaptraps with an overall success rate of 4.7%. Twenty-one species wereeither trapped or observed. Only Microtus pennsylvanicus (Ord) and Peryomuscus leucopus (Fischer) exhibited large populations; while the high point of the study was the trapping of a least weasel (Mustela rixosa Rhoads).