Novel dry forests in southwestern Puerto Rico

We report results of new research on (1) community composition of novel subtropical dry forests developing on abandoned pastures and agricultural fields in both private and protected public lands and (2) seed germination and growth rates of plantings of native tree species on degraded soils. We found that novel dry forests were dominated by introduced species, which accounted for 59 percent of the Importance Value (IV) of stands. These forests had high species dominance, with the most dominant species averaging 51 percent of the IV but reaching values as high as 92 percent. The floristic similarity between novel and mature native forests was low (5.6 percent) compared with the similarity among novel forest stands (26 percent). Collectively, the emerging novel forests had relatively high species richness (39 species/1.2 ha). After 45-60 years of growth and development, novel forests lagged mature native forests in basal area, tree density, and species richness, and lagged stands of similar age and past land use inside a protected area. Novel forest stands inside the protected Guánica Forest had higher species richness than those located outside in private lands. Most regeneration was from seed (67 percent of the new stems were single stems). The results from the germination and planting experiment show that seeds of 17 of 21 native tree species germinated in the laboratory and grew successfully in abandoned pastures when planted and watered for a period of 13 months. Our research shows that after the initial invasion and dominance of introduced species on degraded sites, the stands diversify with native species thus evolving towards new forest types with novel species combinations.     

Diversity and composition of tropical secondary forests recovering from large-scale clearing: results from the 1990 inventory in Puerto Rico

The extensive recovery from agricultural clearing of Puerto Rican forests over the past half-century provides a good opportunity to study tropical forest recovery on a landscape scale. Using ordination and regression techniques, we analyzed forest inventory data from across Puerto Rico’s moist and wet secondary forests to evaluate their species composition and whether the landscape structure of older forest affected tree species composition of recovering forests at this scale. Our results support conclusions from studies conducted in Puerto Rico at smaller scales and temperate forests at larger scales that timing of abandonment and land use history are of overwhelming importance in determining the species composition of recovering forests. Forest recovery is recent enough in Puerto Rico that previous land use is clearly evident in current species composition, and creates new forest communities. As demonstrated in other work, physical factors such as elevation and substrate co-vary with land use history, so that the species composition of the forest landscape results from the interplay between biophysical and socioeconomic forces over time. Our results also indicate that increasing the distance to the largest forest patches occurring in the landscape 12 years previous had a small negative impact on species richness but not species diversity or community composition. We conclude that land use history has as much influence in species composition as biophysical variables and that, at the scale of this study, there is no large influence of forest landscape structure on species diversity or composition.     

Foliar pathogen and insect herbivore effects on two landslide tree species in Puerto Rico

To better understand pathogen/herbivore interactions and landslide regeneration, percent leaf area lost to disease and herbivory on two Puerto Rican trees over a 1-year period was sampled. Cecropia schreberiana saplings lost from 1 to 3% leaf area to pathogens and from 1 to 7% to herbivores. For Inga vera, both sapling and seedling losses to pathogens were minimal, but Inga herbivory losses reached 25% for saplings and 34% for seedlings. The most common fungi on Cecropia leaves were species in the genera Phoma and Phyllosticta, and on Inga leaves was Colletotrichum gloeosporioides. Percent survivorship after 1 year in the field varied among species and life-form (46% for Cecropia saplings, 15% for Inga saplings, 0% for Inga seedlings). There were no effects of pathogens or herbivores on survivorship or growth, but increased levels of herbivory did significantly correlate with total phenolics and condensed tannins in both Inga seedlings and saplings. For both seedlings and saplings of two trees on the neotropic island of Puerto Rico: (1) leaf herbivory was modest and leaf losses to pathogen disease were small; (2) these mechanisms did not affect survivorship or growth; (3) a neotropical tree (I. vera) displayed increased levels of secondary chemicals in its leaves, correlated with increased levels of insect herbivory.     

Ecological rhythms and the management of humid tropical forests: Examples from the Caribbean National Forest,Puerto Rico

A common premise in modern forest management is that land management should operate over large enough spatial and temporal scales that common natural disturbances are present and implicitly considered. Less emphasis has been focused on managing humid tropical forest ecosystems with the periodic ecological processes that occur between disturbances. The central premise of this paper is that timing management activities to periodic ecological processes that occur between disturbances is an additional prerequisite for the effective management of humid tropical forests. Ecological rhythms are defined here as biological or biogeochemical processes that have definable periodicities and include phenological, circadian, biogeochemical, and behavioral processes. The paper documents the use of ecological rhythms in the management of endangered species and water resources in the Caribbean National Forest of Northeastern Puerto Rico. While this type of dynamic management has proven benefits, managers and regulatory agencies have been hesitant to utilize complex, ecologically based dynamic management schedules because they can be difficult to monitor and regulate. Fortunately, recent technological advantages greatly increase the ability to conduct complex real-time, spatially explicit management. Identifying important ecological rhythms and developing administrative structures that can integrate them into management will be a major challenge in both tropical and temperate environments in the coming decades.     

Lithuanian forests and climate change: possible effects on tree species composition

Outputs from the HadCM3 Global Climate Circulation Model according to scenarios A2 and B1 were used for climate change predictions in Lithuania. According to scenario A2, the annual temperature will increase by approximately 4.0 °C from 2061 to 2090, while scenario B1 predicts an increase of 2.0 °C. In contrast to scenario B1, scenario A2 predicts an annual increase in precipitation of 15–20 % at the end of the century. Based on the predicted climatic data for the two scenarios and climate maps by European Food Safety Authority for the EU, we created climate analogues for Lithuania for 2031–2060 and 2061–2090. These areas were overlain by the digital map of native tree species distributions in Europe, which was created from the European Forest Genetic Resources Programme database. If climate changes occur according to scenario B1, in 2031–2060, Lithuania’s climate will become suitable for approximately five to six alien species, such as Acer campestre, Acer pseudoplatanus, Fagus sylvatica, Populus nigra, and Prunus avium. In 2061–2090, these species will be joined by Sorbus domestica and Tilia platyphyllos. If climate changes occur according to scenario A2, at the end of the twenty-first century, Castanea sativa, Quercus pubescens, and Sorbus torminalis could expand this list. With respect to species dispersal rates, there is a high probability that the species A. campestre, A. pseudoplatanus, P. nigra, and P. avium will become immigrants to Lithuanian forests at the end of the twenty-first century. Approximately 20 new species native to Europe will be suitable for cultivation (scenario A2). Climate change will affect the distributions of native species too. An increase in the proportion of deciduous tree species (except Alnus incana) and some reduction in the proportion of conifers, Norway spruce (Picea abies) and Scots pine (Pinus sylvestris), are expected in Lithuanian forests.     

Climate shapes the novel plant communities that form after deforestation in Puerto Rico and the U.S. Virgin Islands

Environmental and past land use controls on tree species assemblages on the Commonwealth of Puerto Rico and the U.S. Virgin Islands were characterized to determine whether biophysical factors or land-use history has been more important in determining the species composition of secondary tropical forests after large-scale forest clearing for agriculture, widespread species introduction, and landscape-scale forest fragmentation. Post-deforestation, secondary forest assemblages are comprehensively described, both as broad general assemblages and island-specific variations by calculating species importance values from forest inventory data. Hierarchical clustering and indicator species analysis defined species assemblages, and then correlations between species assemblages and environmental variables were explored with non-metric multidimensional scaling, analysis of variance and χ² testing. These assemblages are arrayed along environmental gradients of decreasing spring moisture stress, decreasing maximum temperatures, and increasing minimum temperatures. Land-use history is not as important to determining variation in species composition across climatic zones, although several species assemblages are associated with certain geology types or land-use histories. Naturalized tree species are prominent in these secondary forests and contribute to the formation of some novel assemblages, but native late and early successional species also colonize former agricultural land, all influenced by the degree of disturbance. We conclude that environmental factors have an overarching effect on forest species composition across the broader range of climatic, geologic and topographic conditions and larger geographic scales, while land-use history influences subtropical secondary forest species assemblages within a specific climatic zone or set of relatively narrow environmental conditions.     

Tree species composition affects productivity and carbon dynamics of different site types in boreal forests

The objective was to analyse how differences in the initial proportions of tree species and site fertility affect carbon sequestration in living biomass and soil. We used the individual-based simulation model EFIMOD, which is able to simulate spatially explicit competition between trees for light and nutrients. Simulations were carried out for three site types with distinct initial stocks of soil nutrients. For each site, the 100-years undisturbed dynamics of monocultures and mixtures of three tree species (Betula pendula Roth, Pinus sylvestris L. and Picea abies (L.) H. Karst.) was predicted. Changes in the proportions of competing tree species were dependent on the fertility of the site: on poor sites, pine was the most competent species, while on rich sites, spruce increased its proportion during stand succession. Net primary production (NPP) and soil respiration were the highest in stands of two coniferous species and in stands with a high initial proportion of pine. Mixed stands were more productive than monocultures; the highest overyielding was observed with mixtures of two coniferous species. Simulated NPP and carbon stocks in all pools increased from poor to rich sites. The highest carbon stocks in standing biomass were observed for mixtures of conifer species and three-species mixtures; the greatest accumulation of forest floor occurred in stands with high proportions of pine.     

Structure and composition of the seed bank in monospecific and tree species-rich temperate broad-leaved forests

How tree species diversity affects ecosystem functioning is a topic of intensive research. This study compares monospecific and species-rich broad-leaved forests under similar bedrock and climate conditions for the size and composition of their seed bank. We tested the hypotheses that (i) the actual herb-layer vegetation has an only weak influence on the composition of the seed bank, (ii) the species diversity of the seed bank increases with tree-layer diversity, and (iii) tree species forming a more persistent litter layer reduce the number of germinating seeds. The number of seeds and their species composition were investigated in soil cores taken from three soil depths (0–5, 5–10 and 10–20 cm; n = 4, with each 6 sub-samples) in 9 study plots differing in tree species diversity (3 monospecific Fagus plots, 3 plots with Fagus, Fraxinus and Tilia, and 3 plots with Fagus, Fraxinus, Tilia, Carpinus and Acer). Tree species diversity had a much stronger influence on the size and composition of the seed bank than herb-layer diversity or composition, the latter revealing only a low similarity to the corresponding seed bank. The number and species diversity of emerging seedlings decreased significantly with the amount of acidifying Fagus litter, but increased with litter mass of Tilia and other trees with nutrient-rich, rapidly decomposing litter. We conclude that tree species diversity does not influence the seed bank through effects on herb-layer composition, but mostly through differential disturbance histories of the stands and litter quality effects on germination and soil chemistry. From the contrasting effects of Fagus and Tilia leaf litter, it appears that effects of tree species identity are more relevant than influences of tree species diversity itself.     

Interspecific relationships in the forest community dominated by Pinus kwangtungensis, an endangered species endemic to China

Interspecific relationships in a natural forest dominated by Pinus kwangtungensis, a rare and endangered pine species endemic to China, were studied based on inventory data from 7,200 m² plots in Nanling National Nature Reserve. With the aim to quantitatively analyze the relationships of P. kwangtungensis to other species in the forest community and to their habitat, the continuous transect sampling method was employed by placing a horizontal transect (10 m × 120 m) at a 100 m altitudinal interval from 1,100 m to 1,600 m a.s.l., which represents the altitudinal range of P. kwangtungensis in Nanling National Nature Reserve. Each transect was further divided into 12 contiguous quadrats (10 m × 10 m) for plant censuses. Both canonical correspondence analysis (CCA) and cluster analysis were used to detect the interspecific relationships. The results showed the following: 1) occurrence frequency of P. kwangtungensis in Nanling was ranked Class A in terms of Raunkiaer’s law of frequency. P. kwangtungensis dominated in the canopy more than in the subcanopy and understory; 2) both Spearman rank correlation (SRC) coefficients and Pearson correlation coefficients indicated that the number of positive covariation couplets was significantly higher than the negative covariation couplets in the forest community, although SRC appeared to be more sensitive than Pearson correlation analysis. Except for the negative covariation with Litsea elongata, P. kwangtungensis exhibited no significant correlation with other dominant species; 3) altitude, slope, slope aspect, slope shape, thickness of humus layer, and thickness of litter all had significant correlations with the three axes in CCA plot, and the environmental factors in the first two axes defined the ecological conditions of the community. The grouping of the 105 canopy tree species was made according to the characteristics of the species along the first axis. Altitude was the most effective factor influencing the distribution of P. kwangtungensis; 4) variability in spatial distribution among the 105 canopy tree species could be attributed to variations to site environmental factors. The results from CCA and cluster analysis indicated that environmental factors influenced the distribution and ecological characteristics of the plant species in the forest community dominated by P. kwangtungensis. __________ Translated from Acta Ecologica Sinica, 2006, 26(4): 1,063–1,072 [译自: 生态学报]     

Forest land-use history affects the species composition and soil properties of old-aged hillock forests in Estonia

Decisions regarding forest typology, management and protection are often based on the structures of present-day forests, ignoring their successional history. Forests growing on kames, eskers and various moraine hillocks common in regions with Holocene glaciation are good examples of this approach. In Estonia, these forests locally persist as fragments of continuous primary forest, but usually they are situated on former slash-and-burn areas (bushlands) or reforested agricultural land. Our aim was to elucidate the strength of the effect of long-term land-use history on the present-day vegetation compositions of mature hillock forests and their soil chemistry. It appeared that even the mature secondary hillock forests are still distinct from historically continuous stands in terms of species composition. We discovered connections between stand history and species content in hillock forests as well as transformed soil properties. The carbon and nitrogen contents in the humus horizons of secondary forests are lower while their carbon–nitrogen ratios are higher than in continuous forests. The relationship between vegetation and stand history is demonstrated by the higher proportions of anthropophytic and apophytic species in the herb layer of the secondary forests. The presence of species that are tolerant of anthropogenic impact on the secondary hillock forests floor can also be partly explained by the effect of different species in the tree and shrub layers, gaps in the tree canopy, and the boundary effect caused by the small areas of forest patches, neighboring grasslands or fields. The extinction debt in secondary communities should also be considered.     

Distribution of Armillaria species in upland Ozark Mountain forests with respect to site,overstory species composition and oak decline

Armillaria root disease is a contributing factor to oak decline in the Ozark Mountains of central USA. We have identified Armillaria gallica, Armillaria mellea, and Armillaria tabescens in Quercus‐Carya‐Pinus forests of the region. Presence/absence patterns of each Armillaria species as well as all possible Armillaria species combinations were analysed by contingency tables and/or stepwise logistic multiple regressions with principal characteristics of the studied sites and forest stands, both quantitative and qualitative: geographic land‐type association, bedrock type, landform position, slope direction (aspect), soil type and soil surface stone cover, down woody debris, abundance and basal area of woody vegetation and decline mortality by species. Most decline mortality consisted of two red oak species (section Erythrobalanus, Quercus coccinea and Quercus velutina), which also were most sensitive to Armillaria infection. Site characteristics related to the distributions of Armillaria species and decline mortality were also related to the preponderance of Q. coccinea and Q. velutina, regional vegetation history (i.e. conversion of Pinus echinata stands to hardwoods), and the different strategies of territory acquisition and spread of the Armillaria species involved. The presence of A. gallica may reduce the activity of more virulent Armillaria species.     

Forest stand dynamics and sudden oak death: Mortality in mixed-evergreen forests dominated by coast live oak

Sudden oak death (SOD), caused by the recently discovered non-native invasive pathogen, Phytophthora ramorum, has already killed tens of thousands of native coast live oak and tanoak trees in California. Little is known of potential short and long term impacts of this novel plant–pathogen interaction on forest structure and composition. Coast live oak (Quercus agrifolia) and bay laurel (Umbellularia californica) form mixed-evergreen forests along the northern California coast. This study measured tree mortality over a gradient of disease in three time periods. Direct measurements of current mortality were taken during 2004, representing a point-in-time estimate of present and ongoing mortality. Past stand conditions, c. 1994, were estimated using a stand reconstruction technique. Future stand conditions, c. 2014, were calculated by assuming that, given a lack of host resistance, live trees showing signs of the disease in 2004 would die. Results indicate that coast live oaks died at a rate of 4.4–5.5% year⁻¹ between 1994 and 2004 in highly impacted sites, compared with a background rate of 0.49% year⁻¹, a ten-fold increase in mortality. From 2004 to 2014, mortality rates in the same sites were 0.8–2.6% year⁻¹. Over the entire period, in highly impacted sites, a 59–70% loss of coast live oak basal area was predicted, and coast live oak decreased from 60% to 40% of total stand basal area, while bay laurel increased from 22% to 37%. Future stand structures will likely have greater proportions of bay laurel relative to coast live oak.     

Woody species composition,diversity and structure of riparian forests of four watercourses types in Burkina Faso

Riparian forests are classified as endangered ecosystems in general,particularly in sahelian countries like Burkina Faso because of human-induced alterations and civil engineering works.The modification of this important habitat is continuing,with little attention being paid to the ecological or human consequences of these changes.The objective of this study is to describe the variation of woody species diversity and dynamic in riparian forests on different type of watercourse banks along phytogeographical gradient in Burkina Faso.All woody species were systematically measured in 90 sample plots with sides of 50 m × 20 m.Density,dominance,frequency and species and family importance values were computed to characterize the species composition.Different diver-sity indices were calculated to examine the heterogeneity of riparian forests.A total of 196 species representing 139 genera and 51 families were recorded in the overall riparian forests.The species richness of individuals with dbh ≥ 5cm increased significantly from the North to the South along the phytogeographical gradient and varied significantly between the different types of riparian forests.Similarity in tree species composition between riparian forests was low,which indicates high beta diversity and reflects differences in habitat conditions and topography.The structural characteristics varied significantly along the phyto-geographical gradient and between the different types of riparian forests.The diameter class distribution of trees in all riparian forests showed a reverse "J" shaped curve except riparian forest of stream indicating vegetation dominated by juvenile individuals.Considering the ecological importance of riparian forest,there is a need to delineate and classify them along watercourses throughout the country.     

Forest structure and woody plant species composition after a wildfire in beech forests in the north of Iran

Beech (Fagus orientalis Lipsky) forest covers about 565,000 ha of land in Guilan province, north of Iran and forms a major carbon pool. It is an important economic, soil protection and recreation resource. We studied long-term effects of fire on the structure and composition 37 years after fire occurrence in these forests. To do this research, we selected 85 ha burned and 85 ha unburned beech forests). The results indicated that the fire had not changed the overall uneven-aged structure, but it changed forest composition from pure stands to mixed stands that now include species such as Carpinus betulus, Acer cappadocicum and Alnus subcordata. The density of trees and regeneration was significantly increased, while the density of shrubs significantly decreased. The main reasons for increased tree regeneration were attributed to (1) reduction of litter depth, and (2) increase in available light from opening of the canopy and reduction in shrub competition. It is apparent that the forest is on a path to return to its natural state before the fire after 37 years.     

Structure,composition and diversity of tree species in tropical moist deciduous forests of Eastern India: a case study of Nayagarh Forest Division,Odisha

Quantitative assessment of tree species diversity from sample plots in seven forest ranges of Nayagarh Forest Division in Odisha state in the Eastern Ghats of India was made during the period April, 2011 to November, 2013. A total of 120 transects(1000 m × 5 m) were laid in Nayagarh, Odogaon, Pancharida, Khandapada, Dasapalla,Mahipur, and Gania forest ranges and tree stems of at least 30 cm GBH were measured. The regeneration potential of trees was assessed from 5 m × 5 m sample plots located within the main transect. A total of 177 tree species belonging to 120 genera and 44 families were recorded from the study area. Shorea robusta, Buchanania lanzan, Lannea coromandelica, Terminalia alata and Cleistanthus collinus were the predominant tree species. The stand density varied in the range of 355.33–740.53 stems h~a)-1) while basal area ranged from 7.77 to 31.62 m~2 ha~(-1). The tree density and species richness decreased with increasing girth class. The highest number of species and maximum density was recorded in the girth class of 30–60 cm. The Shannon–Weiner and Simpson Indices with respect to trees with C30 cm GBH varied in the range of 2.07–3.79 cm and 0.03–0.37 cm respectively and the values of diversity indices are within the reported range for tropical forests of Indian sub-continent. The families, Dipterocarpaceae,Anacardiaceae, Combretaceae and Euphorbiaceae contributed to maximum species richness, stand density, and basal area. Regeneration of many tree species was observed to be poor. The present study provides baseline data for further ecological studies, forest management, and formulation of site-specific strategies for conservation of biological diversity in moist deciduous forests of Eastern India.     

Soil macrofauna and litter nutrients in three tropical tree plantations on a disturbed site in Puerto Rico

Tree plantations are increasingly common in tropical landscapes due to their multiple uses. Plantations vary in structure and composition, and these variations may alter soil fauna communities. Recent studies have demonstrated the important role of soil fauna in the regulation of plant litter decomposition in the tropics. However, little is known about how plantation species affect soil fauna populations, which may in turn affect the biogeochemistry of the plantation system. We measured soil macroinvertebrate abundance and biomass in 9-year-old N₂-fixing Leucaena leucocephala, Casuarina equisetifolia, and non-N₂-fixing Eucalyptus robusta plantations on a degraded site in Puerto Rico. Nutrient concentrations and standing stocks of forest floor litter were also determined to examine the relationship between litter chemistry and soil macroinvertebrates. Leucaena plantations had significantly higher abundances and biomass of millipede species than Casuarina and Eucalyptus. Earthworm biomass did not differ among plantation treatments. Nitrogen, P, and K concentrations were generally higher in Leucaena litter, which resulted in higher standing stocks of these nutrients in fragmented, moderately decomposed litter (Oe horizon). Millipede biomass was highly correlated to N concentration and C/N ratio in the Oi litter horizon. These results suggest that plantation species differ in their influence on soil fauna, and the biomass and abundance of soil fauna can be regulated through careful selection of plantation species in degraded tropical lands.     

Seedlings of a native shrub can establish under forests dominated by an alien tree, Casuarina equisetifolia, on subtropical oceanic islands

We investigated the effects of litter accumulation by an alien tree, Casuarina equisetifolia, on the germination and seedling establishment of Rhaphiolepis wrightiana, a shrub native to the Ogasawara (Bonin) Islands, in the northwestern Pacific Ocean, in a field experiment. We compared the emergence of seedlings in forests dominated by C. equisetifolia with that in native forests, with and without litter removal. More than 75% of seedlings emerged during a year except at the C. equisetifolia sites with litter removal (approximately 45%). Thus, seeds of R. wrightiana can germinate under C. equisetifolia if they are dispersed on the ground.     

Silvicultural alternatives in an uneven-sized forest dominated by Picea abies

In this article, we report on the increments in basal area and tree diameter as well as the structural development observed in variously thinned plots that underwent either uneven- or even-sized treatment. The experimental forest was originally an uneven-sized mixed stand dominated by Picea abies. Twenty-eight randomized sample plots underwent each treatment, and the trees were monitored for 15 growing seasons after thinning. The uneven-sized plots retained a reverse J-shaped diameter distribution, but this was changed into a bell shape by low thinning in the even-sized plots. Absolute basal area increment was positively correlated with basal area in the even-sized treatment but not in the uneven-sized treatment. In the latter, all of the plots grew almost equally well, and only the basal area of broadleaves explained slightly positively the increment variation. Relative basal area increment was negatively correlated with basal area in both treatments. Additionally, the basal area of Scots pine was a positive explanatory variable in the relative increment variation in the even-sized treatment. For the dominant Norway spruce trees, diameter increment was negatively correlated with basal area in both treatments and, conversely, heavy removal increased the diameter increment. Relative basal area increment averaged 5% annually in uneven-sized plots representing the “target selection.” This was more than double the increment observed for the even-sized plots that represented the “prevailing practice.” Likewise, the diameter increment of Norway spruce trees was 48% greater in the uneven-sized compared to the even-sized plots.     

Diversity and structural composition of species in dipterocarp forests: a study from Fasiakhali Wildlife Sanctuary,Bangladesh

Fasiakhali Wildlife Sanctuary is a protected area composed of tropical remnant rainforest that harbor substantial number of large,old Garjan(Dipterocarpus spp.)trees.The present study assessed composition,structure and diversity of the species in this protected area.A total of 32 trees species were recorded with DBH ≥ 11 cm belonging to 24 genera and 19 families.The forest is low in plant diversity as represented by Shannon–Wiener diversity and Simpson Dominance indices.Dipterocarpus turbinatus was the most dominant species with maximum relative density,frequency,dominance,and importance value index.Syzygium firmum and Tectona grandis followed in terms of dominance.The structural composition indicated higher number of individuals in the medium growth classes(41 to 511 cm DBH and 16–20 m height ranges),whereas D.turbinatus was the only species that dominated most of the growth classes.Poor stem density in lower growth classes indicated meager recruitment of regeneration which may be due to lower annual precipitation,increased grazing and encroachments.This study will help to understand the patterns of tree species composition and diversity in the remnant dipterocarp forests of Bangladesh.It will also contribute to identifying threatened plants to undertake D.turbinatus based conservation and sustainable management of the Fasiakhali Wildlife Sanctuary.     

Avian studies and research opportunities in the Luquillo Experimental Forest: A tropical rain forest in Puerto Rico

The Luquillo Experimental Forest (LEF) located on the Caribbean island of Puerto Rico has a rich history of ecological research, including a variety of avian studies, and is one of the most active ecological research sites in the Neotropics. The LEF spans an elevational range from 100 to 1075 m over which five life zones and four forest types are found in a warm, humid subtropical climate. A total of 23 bird species breeds here and another 76 species, mostly migrants, are known to occur. The food web of the forest in the lower elevations is especially well studied, which allows an assessment of the role of birds in the food web. The LEF is noted for its high densities of Eleutherodactylus frogs and Anolis lizards, which may depress insect densities thereby contributing to the low species richness and densities of most insectivorous birds. The signature species of the forest is the endangered Puerto Rican Parrot (Amazona vittata) that has been the focus of intensive long-term research and recovery efforts, which have spawned research on associated species, including long-term studies on the Pearly-eyed Thrasher (Margarops fuscatus) and botfly (Philornis spp.) ectoparasitism. Given the frequency of hurricane disturbance to the LEF and studies providing baseline for comparisons, research has made major contributions to an understanding of the effects of hurricanes on forest ecosystems including bird populations and their resources. We summarize these and other studies from the LEF to characterize the avifauna and its environment while noting studies with management implications and identify opportunities for future ornithological studies.