Mamoní Land Use Classification Primer
In the process of assessing interventions to enhance the quality of Mamoní Valley forestation, we consider the following 17 classes of land cover. Nine of these classifications deserve some level of intervention.
Primary forest sites are areas with little or no human intervention and large (200+cm diameter) trees. Forests have fully closed canopies and a well-developed canopy structure. Typically dominated by later-successional tree species, and found in only the most remote, inaccessible portions of the Valley, these are high conservation value lands. Potential uses include Watershed protection, Non-Timber Forest Product Extraction, Selective Logging, and Eco-tourism.
Mature Secondary Forest
Mature Secondary Forest sites are areas that have been intervened in the last 50 years but are still well-developed forests with many larger (30-250cm) trees. They are closed canopy except for any sites of human intervention to harvest larger, valuable trees. These forests have a developed canopy structure with a mixture of taller pioneer trees (often senescent) with a younger age cohort of mid-story and understory trees from later-successional tree species and understory palms and shrubs covering much of the forest floor. Potential uses include Watershed protection, Non-Timber Forest Product Extraction, Enrichment Plantings, Selective Logging, and Eco-tourism.
Young Secondary Forest
Young Secondary Forest sites are one of the most common land cover classes in the Valley. These are areas that have regrown from pastures in the last decade or two and have fully colonized a site with 100% canopy closure. These forest structures are still relatively young, with mostly smaller trees (10-25cm diameters), and a few larger specimens of early successional trees. Young secondary forests demonstrate a “stem exclusion phase” of stand development, in which there is fierce competition between a large number of trees for limited growing space. Selective thinning and pruning can provide for higher quality timbers and the allocation of growing space and tree volume to desired species. This land cover class is also a good candidate for enrichment plantings of later-successional species as well as several crops. These are for the most part closed canopy sites, though there may be opportunity for clearing interventions in less dense areas. Potential uses include Watershed Protection, Enrichment Plantings, and Source for Deadwood Posts for fencing.
High Closed Rastrojo
High Closed Rastrojo is encountered in areas that have been left to recuperate from 4-7 years with smaller disaggregated trees 10-15cm in diameter. This land cover class typically has a very high density of individuals competing for growing space, with many of the crowns touching with a total canopy closure of 60-100%. The trees are typically 3-7 meters in height. All trees are early successional species with fast growth and typically low wood quality. These sites have very little presence of cattle as there is almost no light penetration to the ground and no grasses for grazing. This is the last stage of field colonization before the site becomes classified as a forest, and this is the worst land cover class in terms of being able to move through it, as it is an intermeshed mess of biomass, including vines, shrubs and small trees with no gaps. These are the most important lands to clear for planting in order to ultimately create a higher quality forest. Potential short term uses include Enrichment Planting, Agroforestry, Agriculture, and Cattle Raising.
High Open Rastrojo
High Open Rastrojo is encountered in areas that have been left to recuperate from 4-7 years with the presence of cattle grazing. The sites are typified by clumps of smaller trees 10- 15cm in diameter with 20-60% forest cover. Within the treed clumps there is a very high density of individuals competing for growing space, with many of the crowns touching. This land cover class has been maintained by cattle, and as such has ample grazing lands interspersed. The trees are typically 3-7 meters in height and are early successional species with fast growth. High Open Rastrojo is high priority for fencing and clearing for cattle operations and later planting before it reverts to low-quality forest. Potential short-term uses include Enrichment Planting, Agroforestry, Agriculture, and Cattle Raising.
Low Closed Rastrojo
Low Closed Rastrojo describe areas that have been left to recuperate naturally for at least two (2), and up to four (4) years with little or no presence of cattle and 60-100% forest cover. The smallish trees are mixed in a matrix of shrubs, vines, herbaceous plants and often ferns and tall grasses, and this dense foliage makes this one of the most impenetrable plant communities in the Valley. The trees in this mix are typically 2-4 meters in height and are early successional species with fast growth. Low Closed Rastrojo is a high priority for fencing and clearing for cattle operations with the option to then convert the sites to the plantings of choice.
Low Open Rastrojo
Low Open Rastrojo has been left for natural forest colonization for at least two (2) years or left abandoned for four (4) years with the continuous presence of cattle and 20-60% forest cover. The smallish trees are mixed in a matrix of shrubs, vines, herbaceous plants and often ferns and tall grasses, and this foliage is far less dense than the Low Closed Rastrojo, with large patches of open grass intermixed. The trees are typically 2-4 meters in height and are early successional species with fast growth. Low Open Rastrojo is great for cattle with the option for subsequent planting, as it already has ample pasture space having been maintained by livestock’s presence.
Pasture with Small Shrubs
Pasture with Small Shrubs has been left to recuperate naturally for at most two (2) years and most likely has a continuous presence of cattle. The smallish 0-2m shrubs are sparsely spread throughout the pastures, and are typically herbaceous, with some woody stemmed, baby trees. These sites are at most 20% forested and are great for cattle, with wide-open pasture space maintained by livestock, and typically human intervention as well. Ultimately they can be developed into anything that promotes the biocultural diversity of the Valley.
Pastures are mostly found where there is still active grazing and human site maintenance, typically via machete or spraying. Maintaining a pasture in the Mamoní Valley is a difficult exercise as most areas that have been left to recuperate naturally pass quickly to Pasture with Small Shrubs and then onto the various stages of rastrojo. These sites are great for cattle, and can also easily be planted provided there is adequate fencing.
Dense thickets of Ferns (Fam. Pterydophytae) can completely choke out sites and prevent forest succession by occupying all available growing space. These sites are notoriously snaky and in clearing them the utmost caution must be exercised. The dense growth is exceptionally difficult to clear and can cost $500+ per hectare to clear, burn, and return to a useable state for cattle or plantings. Ferns typically take-over in more acidic, degraded soils.
Aggressive Canal Grass (Saccharum spontaneum) is a non-native invasive species brought from SE Asia in the early 20th Century to help control erosion in the Panama Canal Watershed. It’s windblown seeds and incredibly thick growing style make it nearly impossible to control and it spreads quickly. Even more so than ferns, this grass completely chokes out sites and prevents forest succession by occupying all available growing space. The grass is the hardest plant to control in the Valley, and can cost $1000+ per hectare to remove. The goal is not so much to eliminate the Canal Grass but rather to prevent its spread. Grazing by aggressive goats is one method of control.
Wetlands are areas with standing water and specific plant communities dominated by evergreen herbaceous vegetation. They provide a high quality habitat for amphibians and serve as a filter for runoff from properties. These are high conservation value sites that merit protection.
Rivers and Streams
Stream corridors with “Gallery Forest” have a special treatment in Panamanian environmental legislation. All flowing watercourses are legally required to be forested on both sides of the river or stream to at least the width of the watercourse itself. These river corridors are important for the movement of animals through the settled landscape, and many monkeys frequent these corridors. Rivers and Streams are high quality habitat and these high conservation value sites must be protected and restored where inadequately forested.
Forest plantations are found throughout the Upper Mamoní watershed, varying in the management of their ultimate reversion to mature forests. One example is ForestFinance’s plantings in the eastern portion of the Valley.
Two new Guadua angustifolia Bamboo plantations have been established in the Valley on Mamomí 100 landholdings. There are also several patches of the native common bamboo, Bambusa vulgaris found at Centro Mamoní and other properties in the Valley. One property also has a species of Chusquea sp. bamboo along the roadway. Productive cultivation of Guadua bamboo offers watershed protection, forestry production, and material for local housing. When properly managed and planted with selected tree species, bamboo plantations can revert to high quality forests.
Several patches of annual and perennial crops are found in and around the Valley. These patches contain corn, cassava, breadfruit, taro, mango, guava, and avocado. Although often grown on illegally cleared land, these small uses of land for agriculture are important for food production for the local communities.
There are many sites of human habitation in the Valley. Besides the four villages and many active farmsteads, there are a number of abandoned sites in various stages of disrepair. These include old concrete slabs, ramshackle zinc panel buildings, and the remains of fence lines, corrals, and latrine slabs.