About the study site

The east slope of the Cordillera Oriental near Villavicencio is an area of high biodiversity and endemism. The forest is categorized as very humid tropical lowland forest with rainfall averaging 4,400 mm per year. The dry season occurs during the January and February when it usually rains less than 100 mm/month. The transition to the rainy season starts around the middle of March and the rains taper off in December. Average yearly daily temperature is 26.5° C. The river systems are all Orinoco drainage up to the Sierra de la Macarena.

The study area is a little fragment of tropical forest located behind the lab (my house) a few kms from the town of Villavicencio, Colombia at 04° 03′ N, 73° 42′ W and 495 m above sea level. The wooded area is 30 m wide x 100 m long and covers an intermittent stream. The site is isolated on the two long sides by an agricultural land matrix but the linear forest strip is continuous to the north following the stream. This protective tree cover over the stream plus some hedgerows here and there produce a faunal corridor that leads to a 30 hectare fragment of forest on a neighboring farm 800 m away. The neighbor’s forest is then connected by corridors to the larger forest on the slope of the mountain some 2 km distant. The forest canopy is between 15 and 20 meters in height and consists of about a dozen old trees with a diameter greater than 50 cm scattered throughout the site and a larger number of younger trees with a diameter of 10-30 cm. The large edge/area ratio allows entrance to pioneer species like Cecropia, Vismia and especially Miconia which are a common species in the forest. In the past, before the survey was started, the understory plants were clear cut as is custom in the region but now the uncut understory is a luxuriant carpet of plants. In the low swampy areas grow thickets of  Calathea (Marantaceae) and in the higher areas are many species of Rubiceae, Solanaceae, Araceae, ferns and grasses.

Weather data is collected on a daily basis. Rainfall is measured with a wireless Acu-rite rain gauge and the temperature and humidity in the forest is transmitted from a Lascar data logger via Wifi to my computer.

Looking at the edge of the woods from the stream

A satellite view of the area around the study site. The lighter green areas are agricultural land, mostly pastures, and the dark green areas are forest fragments. For reference, the dark patch of forest above the study site is about 30 hectares.