Tropical Ecology and Conservation [Monteverde Institute]

Files

Download

Download Full Text (571 KB)

Publication Date

September 1999

Abstract

Fallen tree logs provide an ideal moist habitat for Arachnids in the Order Opiliones. This study compares pasture and forest logs to determine which of the two habitat types Opiliones prefer. Log size and degree of decomposition were examined to determine their effect on Opilion abundance and species richness. Logs in pasture and forest sites at Monteverde and Cañitas, Costa Rica were overturned and searched for Opiliones. Opiliones were found to be more abundant and species rich in the pasture than in the forest. However, forest logs have a higher index of diversity than pasture logs. A positive correlation was found between volume (size) and species richness (forest: p = 0.024, r = 0.0207; pasture: p = 0.001, r = -0.295) and between volume and Opilion abundance in pasture logs (p < 0.0001, r = 0.401) but not in forest logs (p = 0.063, r = 0.171). No correlation was found between degree of decomposition and Opilion abundance (forest: p = 0.839, r = 0.019; pasture: p = 0.598, r = 0.048) or species richness (forest: p = 0.916, r = 0.01; pasture p = 0.875, r = 0.014). Negative effects of deforestation on Opilion diversity were looked at in global terms and reasons for these effects were hypothesized and discussed. Arboles caídos provén un hábitat ideal para invertebrados en la Orden Opiliones. Este estudio compara troncos en el potrero y troncos en el bosque para determinar cuál de los dos hábitats prefieren. También examina el tamaño y el grado de descomposición de troncos en el suelo para determinar el efecto de estos factores a la abundancia de Opiliones. Troncos en sitios de potrero y bosque fueron examinados por Opiliones. Fue descubierta que hay más Opiliones y más especies de Opiliones en el potrero que en el bosque. Sin embargo, troncos en el bosque tiene un índice de diversidad más grande que troncos en el potrero. Una correlación positiva fue descubierta entre volumen (tamaño) y cantidad de especies (bosque = 0.024, r = 0.0207; potrero: p = 0.001, r = -0.295) y entre volumen y la abundancia de Opiliones en el potrero (p < 0.0001, r = 0.401) pero no en el bosque (p = 0.063, r = 0.171). No descubrí una correlación entre el grado de descomposición y la abundancia de Opiliones (bosque: p = 0.839, r = 0.019; potrero: p = 0.598, r = 0.048) o la cantidad de especies de Opiliones (bosque: p = 0.916, r = 0.01; potrero: p = 0.875, r = 0.014). Los efectos negativos de deforestación fueron examinados en términos globales y razones por estos efectos fueron discutidos.

Description

Student affilliation: Department of Biology, Occidental College Born Digital

Genre

Reports

Holding Location

Monteverde Institute MVI

Identifier

M39-00013

Opiliones abundance and species diversity in pasture and forest logs

Share

COinS
 
 

To view the content in your browser, please download Adobe Reader or, alternately,
you may Download the file to your hard drive.

NOTE: The latest versions of Adobe Reader do not support viewing PDF files within Firefox on Mac OS and if you are using a modern (Intel) Mac, there is no official plugin for viewing PDF files within the browser window.