Our forest

IMPORTANT BACKGROUND TO THIS FOREST:

Over the past several centuries, Puerto Rico’s original forests were extensively logged and converted for agricultural purposes, leading to significant loss of native forest cover. However, a decline in agricultural land use, combined with broader socio-economic changes, has allowed large areas to revert to secondary forest. Between 1980 and 2003, Puerto Rico reported a net forest gain of 211,650 hectares—making it one of the few regions globally to experience such extensive forest recovery. As of the early 2000s, forest cover reached approximately 57% of the island’s land surface, a substantial increase from a low of 17% in the 1930s (Brandeis et al., 2007).

Despite their ecological significance, secondary forests are frequently undervalued due to long maturation periods for timber species and perceptions of limited economic return. This misperception increases their vulnerability to degradation through clear-cutting, grazing, agricultural conversion, or poorly planned development.

Research into the sustainable management of tropical secondary forests is therefore essential—not only for conserving biodiversity and ecosystem function but also for supporting long-term economic viability. Enrichment planting, a silvicultural approach involving the introduction of high-value native tree species into existing forest stands through selective clearing, has proven effective in accelerating forest recovery while maintaining ecological integrity. This method mimics natural disturbance regimes and enhances soil protection, species diversity, and forest structure (Shono et al., 2007).

For over four decades, Las Casas de la Selva has served as a living laboratory for the application of enrichment planting as a core silvicultural practice. The ongoing work at this site underscores the critical importance of treating secondary forests as a renewable natural resource. Advancing sustainable forest management in Puerto Rico offers a scientifically grounded, ecologically responsible pathway toward increased self-sufficiency and reduced reliance on imported timber.

Geographic and Biophysical Description:

Located at 18° 4’ 0’’N, 66° 2’ 30’’W, the forest lies in the Sierra de Cayey in southeastern Puerto Rico, within the Municipality of Patillas. It borders the Carite State Forest and spans 930 acres). The property is part of the Río Grande de Patillas watershed and is bordered by the districts of Muñoz Rivera, Mulas, and Marín.

The topography is rugged and mountainous, with the majority of the land exhibiting steep slopes ranging from 40 to 60 degrees. Numerous tributaries and small creeks traverse the property, feeding into the Río Grande de Patillas. The site features striking natural elements including dense forest cover, cascading streams, and waterfalls.

This region is classified as a subtropical wet forest under the Holdridge Life Zone System and as very humid evergreen montano tropical forest under the Walsh classification. Elevation across the property ranges from 300 to 600 meters (980 to 1,970 feet) above sea level, supporting high biodiversity and a complex vertical forest structure characteristic of montane tropical ecosystems.

Climate:

The Río Grande de Patillas basin falls within the subtropical moist forest and subtropical very moist forest zones. The region experiences frequent and often heavy rainfall throughout much of the year, particularly in the Carite Forest. Rainfall distribution follows a bimodal pattern typical of Puerto Rico, with a relatively dry season from January to April, a pronounced rainy period in May, a secondary drier phase from June to August, and a return to heavy rains through December.

Average annual precipitation across the basin is approximately 81 inches (2.05 m), though it varies from 56 inches along the coastal areas to as much as 105 inches (2.66 m) in the higher elevations of the Carite Forest. In years of severe drought, total rainfall can drop to about 57 inches. Evapotranspiration accounts for approximately 60% of the annual rainfall, equating to around 48 inches in average years and 43 inches in drier years. The remaining 33 inches contributes to surface runoff or infiltrates into the groundwater system.

Temperature data from Cooperative Weather Station #66-6904 (Patillas Dam) indicate an average annual temperature of 78.0°F (25.55°C), with mean precipitation between 75 and 85 inches. At Las Casas de la Selva, 102 inches of rainfall were recorded between May 2009 and May 2010, illustrating the site’s high precipitation potential and hydrological significance within the watershed.

Hydrology:

The Tropic Ventures property lies within the Humacao–Río Seco Basin in the Río Grande de Patillas watershed in southeastern Puerto Rico, primarily in the municipality of Patillas, with some areas extending into Arroyo. At least five intermittent streams and tributaries cross the land, all contributing to the watershed.

The terrain is characterized by steep, forested hills reaching elevations up to 2,988 feet. To the north, the Carite State Forest—established in 1935 to protect critical headwaters—borders the property and supports the origins of major rivers, including the Río Grande de Patillas.

This river flows southward from Carite through the project site, passing through the Muñoz Rivera, Jagual, and Marín wards before reaching the broad alluvial valley and the Patillas reservoir (Lake Patillas). The reservoir, built between 1910–1914 and managed by PREPA, stores 18.5 million cubic meters (15,000 acre-feet) of water and supplies the region with water for domestic use and agriculture. It is fed by the Río Grande de Patillas and Río Marín and supports aquatic life including guabinas, chopas, dajaos, lobinas, and tilapia.

Soils:

This soil area, described as humid, is classified as an association known as Pandura Rocosa Tierra Patillas. According to the General Soil Map in the “Soil Survey of Humacao Area of Eastern Puerto Rico”, they range from shallow, moderate cliffs to big cliffs with good drainage and elevated plutonic lands.

There are 3 types of associated soils within these lands:

1. CbF2- Caguabo arcilloso lómico, from 20 to 60% slope with erosion potential.
2. LsF2- Los Guineos limoso arcilloso lómico, from 40 to 60% slope with erosion potential.
3. PaF2- Pandura lómico, from 40 to 60% slope with erosion potential.