Treesearch

Tropical dry forests in the Caribbean have an uniquely short, shrubby structure with a high proportion of multiple-stemmed trees compared to dry forests elsewhere in the Neotropics. Previous studies have shown that this structure can arise without the loss of main stems from cutting, grazing, or other human intervention. The Caribbean has a high frequency of hurricanes, so wind may also influence forest stature. Furthermore, these forests also tend to grow on soils with low amounts of available phosphorus, which may also influence structure. The objective of this study was to assess the...

We studied the ecological characteristics of 45.50-yr-old subtropical dry forest stands in Puerto Rico that were growing on sites that had been deforested and used intensively for up to 128 yr. The study took place in the Guánica Commonwealth Forest. Our objective was to assess the long-term effects of previous land use on this forest.i.e., its species composition, structure, and functioning. Previous land-use types included houses, farmlands, and charcoal pits. Stands with these land uses were compared with a nearby mature forest stand. The speed and path of forest recovery after deforesta...

We studied physiognomy-specific (i.e., gaps vs. understory) responses of birds to low harvest (18.7 m3/ha), reduced-impact logging by comparing 3500 mist net captures in control and cut blocks of an Amazonian terra firme forest in Brazil at 20–42 mo postharvest. Species richness did not differ significantly between control (92 species) and cut (85) forest based on rarefaction to 1200 captures. Fifty-six percent of all species were shared between control and cut forest, compared to the 64 percent shared between control blocks. Higher captures of nectarivores and frugivores in cut forest...

Summary Actual evapotranspiration (aET) and related processes in tropical forests can explain 70% of the lateral global energy transport through latent heat, and therefore are very important in the redistribution of water on the Earth’s surface [Mauser, M., Scha¨dlich, S., 1998. Modelling the spatial distribution of evapotranspiration on different scales using remote sensing data. J. Hydrol. 212–213, 250–267]. Unfortunately, there are few spatial studies of these processes in tropical forests. This research integrates one Landsat Thematic Mapper (TM) image and three Moderate Resolution...

Nitrogen (N) and phosphorus (P) are the nutrients that most commonly limit tree growth. Interactions between fertilization and soil type are well known, and in soils with moderate or low N availability, N-fertilization is frequently recommended to improve tree nutrition. The aim of this paper was to analyze how different doses of P and N applied in three different types of soils affect dry mass and nutrient accumulation and partitioning in Eucalyptus grandis young plants, and if fertilization with P may increase N uptake. Fertilization was applied as 1, 2 and 4 g of urea (46% of N) or 6,...

The ability to resist hurricane damage is a property of both individuals and communities, and can have strong effects on the structure and function of many tropical forests. We examined the relative importance of tree size, species, biogeographic origin, local topography, and damage from previous storms in long-term permanent plots in a rehabilitated subtropical moist forest in Puerto Rico following Hurricane Georges in order to better predict patterns of resistance. Severe damage included uprooted trees, snapped stems, or crowns with greater than 50 percent branch loss. Hurricane induced...

Five permanent plots were established along an elevational gradient in the San Patricio urban forest. At the time of the study (August, 2004) we found 29 forest species in a 0.19 ha area. Of these, seven were introduced and dominated the mogote valley where there had previously been a military base. The slopes and top of the mogote were dominated by native species, particularly Coccoloba diversifolia. Regeneration included foreign and native species that dominated the valley and the high areas of the mogote, respectively. The structure of the five stands was similar to tree densities...

We studied an urban forest established in 1988 by residents of the El Paraíso urbanization. In 2007 the forest had 37 forest species (9 native and 28 introduced) with diameter at breast height (dbh) ≥ 4 cm in a 1.0785 ha area. The most common species was the hybrid mahogany (Swietenia macrophylla x mahagony) with an Importance Value of 24.3 percent. The forest had two species endemic to Puerto Rico (maga or Thespesia grandiflora and the royal palm or Roystonea borinquena) as well as native primary forest species such as bulletwood or ausubo (Manilkara bidentata) and lignum vitae or...

From 1995 to 2003 we measured growth in basal area and height of all trees with a diameter at breast heigh (1.3m) of ≥ 2 and < 4cm (understory trees) and ≥ 4cm (canopy trees) in a secondary forest located in Utuado’s coffee zone. The forest is in the subtropical wet life zone transitioning to humid in the Jácana sector of Caguana Ward. During September 21-22, 1998, hurricane Georges passed through the stand with maximum sustained winds of 184 km/h and gusts of 240 km/h. Growth rates were analyzed during three stages: before the hurricane, immediately after the hurricane, and four years...