Tropical Ecology Program

Introduction

        Tropical regions harbor most of the biological diversity of the world.  However, due to social, economic and political factors, most pristine ecosystems in the tropics are highly endangered.  Most tropical regions lack the professionals and resources to study and administer the natural habitats properly, thus it is crucial to train biologist in this discipline.  This series of courses is intended to provide undergraduate, and beginning graduate students, insight into the study of tropical ecology.  The program is designed for upper level undergraduate students and graduate students who have completed at least one academic course in each of the following:  ecology, evolution, and genetics.

        This program comprises the whole academic load for the term.  It has a strong field component where the students will be introduced to ecological and evolutionary processes in the tropics, the scientific method, and the formulation of testable hypotheses, and then apply what they have learned to independent basic research projects.  Students will conduct 6 projects in different areas, present their findings orally and in written form in a standard publication format. 

        The program stresses the application of basic ecological concepts and how they apply in the different parts of the tropics.   Comparisons with the base line information the students have from temperate regions will be emphasized.  The program is composed of five courses that complement each other and constitute a total of 15 credits.  Basic Ecological Concepts (2 credits) Ecology of High Elevations (2 credits), Ecology of Rain Forest (4 credits), Coastal Ecology (3 credits) and Independent Projects (4 credits). See syllabi

Plan of Activities

        The program will begin with a month of lectures and field work in East Tennessee.  In this phase of the program, the students will receive an introduction to tropical ecology and conduct field work in the southern Appalachians in order to have a basis of comparing temperate and tropical environments.  They will measure variables such as canopy density, age and size composition of the tree population, species richness and other characteristics that describe the forest.  When we visit the tropics students will assess the new habitats looking at the same variables, which will give them a better idea of how the ecosystems compare. The center piece of the program will be an intensive 36 day field experience  in Ecuador.   Sites visited will be high-elevation sites (Guajalito and Páramo de Papallacta), the Amazon rainforest at Yasuní National Park, and Puerto Caraquez shores and Galapagos Islands for the coastal ecology.   During the field trips, students will collect data on the ecology of different habitats and conduct individual research projects.  Upon their return to the United States, they will write their results and present them in a publication format.  Students will be required to give three oral presentations of their work in the format of meeting presentation.

Basic Ecological Concepts (syllabus)

        This phase of the program, to be held on campus in Knoxville, will be an introduction to the tropics and a review of basic ecological concepts and how they apply to the tropical zone.  The intention is to bring the student up to speed with the basic concepts that they have learned in other courses (e.g., Biology 250: General Ecology) as well as to provide a basic introduction to important aspects of tropical ecology.
                                    

Site courses

        Each course for the sites that we visit (High Elevation Ecology, Coastal Ecology, and Rainforest Ecology) will include a physical description of the habitat and how the biotic and abiotic variables interact.  We will cover the basic ecological processes and how they are affected by the particular conditions of the particular habitats. We will also review the main representative plants and animals of the area and their roll in the ecosystem of which they are a part.  Along with the ecological concepts, in all the sites we will also discuss the conservation problems present in each region.  

Independent projects

        Every site visit will include an initial guided hike introducing the relevant fauna and flora as well as an explication of that dynamics of the system.  Students will be informed of the basic natural history of the animals and plants so they can formulate appropriate questions for feasible short-term projects.  After the initial guided trip students will discuss with the instructor and the other participants the projects they want to do and the hypotheses they want to test.  Once a project is approved, the student will carry it out alone or in teams.  The professor will supervise the data collection and suggest changes in the project design that may be necessary.

Evaluation of Students and Grading

        Student will be tested before departure for Ecuador with a written examination covering the content of all of the lecture classes.  This exam will determine the grade for the entire Basic Ecological Concepts course and 40% of the grade for each of the site-specific courses.  At the end of each site course, there will be a practical exam worth 20% of the grade where students will be asked to identify different organisms and explain major aspects of their life history.  They will be required to keep notebooks in which they will record their observations and data.  This notebook will be turned in to the instructor at the end of the course and graded, the grade being worth 20% of the site grade. The remaining 20% of will be assigned by their participation on the discussions and overall performance.  The evaluation of the Independent Projects will be based on the grade they obtain on the projects and written reports (70%) and the performance of the oral presentation (30%).

High Elevation Ecology (2 Credits) (Syllabus)
Virtual visit
        This course studies the influence of high elevation on the different aspect defining the ecosystem its dynamics, the adaptations of the different organisms to physical demands high altitude.  We will compare how elevation affects the communities in temperate zones and in tropical zones.  Students also will discuss and learn about the conservation problems of tropical mountainous ecosystems and how they relate to the culture and economic status of the areas. 

        The theoretical classes of this course will be taught in Knoxville before the field trip to the Tropics.  During the time we are in Knoxville we also organize a trip to study the influence of elevation on the plant community in the Smoky Mountain National Park.  Students have the opportunity to see the effect of elevation on the plant community.  When we go to Ecuador we visit the high elevation Páramo, the elfin forest, cloud forest, all the way down to the low elevation forest comparing them and showing the effect of altitude.  This combination will allow the students compare the effect of elevation in the temperate regions with the effects of it in the tropics.




Coastal Ecology (3 Credits) (Syllabus)
Virtual visit
        In this course students receive and introduction to marine and coastal ecology and how the basic ecological process work and how the tropics differ from the temperate zones.  Emphasis will be made on the inter-tidal organisms and how the cope with the different environmental pressures that the find in their habitats. 
The theoretical classes will be taught in Knoxville and the field trip will be done in the Manabita shore at Bahía de Caraquez for 7 days and at the Galapagos islands for another 7 days.  First students will go to  the Ecuadorian shore where they will be introduced to the most common inter-tidal organisms and their natural history.  Then students will have the rest of the days to develop and test ecological hypotheses on the organisms of the area.   The last part of the coastal ecology part will be at the Galapagos Islands where we will rent a boat and travel the islands for other 7 days.  Due to the high levels of protection on the islands it will not be possible to do any experimental manipulation on the Galapagos.  Instead, we will visit the islands get acquaintance with the different organisms, their ecology, biogeographic history, and adaptive radiation.   


Rainforest Ecology  (4 Credits) (Syllabus)
Virtual visit
        This course deals with the basic ecological process and the dynamics of the rainforest.  Emphasis will be made on the high diversity of the area and the reasons for such diversity comparing it with the temperate forest studied at the beginning

    The theoretical classes will be in Knoxville before we go to the field.  Once we arrive to Yasuni, students will be introduced to the most common organisms of the area that will be the subjects to their projects.  In the following days in the rain forest students will formulate specific hypothesis and develop testable experimental designs to test their predictions.  The rainforest station is where most of the data collection for the projects will be carried out since is the longest permanence of the field trip.

Independent Projects  (4 Credits)

        Upon arrival at a site, students will be taken on a guided orientation hike and informed of the basic natural history of the animals and plants they can expect to encounter so that they can formulate appropriate questions for feasible short-term projects.  After this initial hike, students will discuss with the instructor and other participants the projects they want to do and the hypotheses they wish to test.  Once a project is approved by the instructor, the students will work individually or in teams to carry out the data-collection phase of the project.  The instructor will supervise the data collection and may suggest changes in the project design if they are found to be necessary.

        The goal of this course is that the students gain experience in the formulation of testable hypotheses, and in designing simple but efficient experimental procedures in order to test these hypotheses.  The also learn to collect, analyze, and interpret their data, and to present their findings in a scientific format.  Students will receive a guerrilla course in statistics as well as basic experimental design in order to provide them with the tools to develop and formulate their projects.  They will also receive instruction and guidance in how to write a scientific paper and how to put together an oral presentation

        Students will do six projects during the course.  One of these will be a pre-designed comparative project in which they will investigate changes in plant communities along elevational gradients in the temperate zone and the tropics.  The remaining five projects will be of the student’s choice and will depend both on the student’s interests as well as the opportunities that found in the field.  Students will write up their projects following the format of scientific journals.  Their papers will be revised and reviewed (as in a ms for a journal) by the instructor but not graded after the first iteration.  After considering the review, write the final version of the papers upon which that grade will be based.

        Students will choose 3 of their projects to present orally, as if in a scientific conference.  Two of these presentations will be during the semester in front of their fellow class members and the instructor, and the third will presented in an open and meeting-like setting attended to a broader audience. 

NOTE:  Each of the following courses will be taught both at the University of Tennessee and in Ecuador.  The number of hours (e.g., 2h) indicated following each topic refers to lecture hours at UT.  The number of field days associated with each course is indicated at the end of the description of each course.

Basic Concepts and Introduction to the Tropics (2 Credits)

This section is intended as a review of material to which the students have been introduced in basic courses in ecology, evolution and genetics and illustrate the relevance of these to questions in tropical ecology.

Basic Concepts

Population growth (2h):  Exponential and logistic growth models and the conditions in which they occur; Age-structured populations: survival fertility, migration, immigration, life history strategies.
  
Species Interactions (2h):  Competition:  Lotka-Volterra model, equilibrium, competitive exclusion, generalist vs specialist. Succession: Definition of seral stages, mature vs secundary forest, successional species typical of the tropics, lianas.  Predation: Equilibrium, extinction, arm-races.

Biogeography (2h): Isolation, evolutionary concepts, vicariance, bottle necks, founder effects.
Biodiversity (2h):  Definition, geographical trends, altitudinal trends, tools to measure diversity, richness vs evenness. 

High Elevation Ecology

Paramo

Geology and geomorphology  (1h):  Origin of the Andes, geology, plate tectonics, soil formation and other abiotic variables.

Climate (1h): Gradient of moisture in the Andes: wetter in eastern puna, drier xerophyllic Venezuela to northern Peru and more southerly; "Winter each night, summer every day"; less dense atmosphere, tremendous fluctuation in temperature and solar intensity, strong desiccation potential, short rainy season, natural freeze drying (e.g., cadaver mummification in puna).

Landscape (1h):  Inferior Páramo 3300-4000m in temperate zone, less than 3000m, dominated by shrubby vegetation; mid-Páramo 4000-4500m, dominated by grasses; superior Páramo, more than 4500m up to 6300m, dominated by cushion plants and lichens; review of representative plants and fauna of the area.

Ecological processes (2h): Particular environmental circumstances of the Páramo and how it affects productivity, competition, and specialization of the species in the area. 

Adaptations (1h): Low standing biomass, low rate of nutrient cycling, high level of radiation, little available water; influence of increasing elevation: decrease in stature of plants, decrease of leaf surface area, increase of silica content; small leaves (microphylly), protected meristems, tough leaves (sclerophylly).

Disturbances and conservation (2h): Grazing, fire, agriculture, steep slopes, easy erosion; other human impacts; main endangered species

Biogeography (2h):  Relate biogeography and speciation to uplifting of the Andes and shifts in climatic zones and the glacial line during the Pleistocene.

Cloud Forest

Geology and Climate (2h): steep mountain slopes, landslides, saturated soils, soils; orographic high rainfall, mist, fog.

Landscape and diversity (2h): Location, characteristics. Soil depths, wind.  Elevation bars, no tree line, Elfin forest.  Low light availability, tallest trees moderate in height,  Epiphytes, epiphylls, and hemi-epiphyte.  Advantages of the different strategies under the frame work of light competition.

Ecological dynamic (2h):  Particular environmental circumstances of the cloud forest and how it affects productivity, competition, and specializations of the species in the area.  

Adaptations (2h): Adaptations to superficial soils, lower altitude compared with rain forest, quicker recycling of nutrients compared as compare to paramo; dense understory, large numbers of epiphytes and hemi-epiphytes; mud slides relatively common.

Disturbances and conservation (8h): logging, fire, agriculture, steep slopes and erosion; other human impacts; main endangered species.

Flora (2h)

Main families: Asteraceae (Werneria sp., Gynoxis sp., Loricaria sp.), Fabaceae (Lupinus sp.), Poaceae (Agrostis sp., Calamagrostis sp., Stipa sp.), Apiaceae (Azorella sp.), Ericaceae (blueberries down into cloud forests), Verbenaceae (Verbena sp.), Scrophulariaceae (Calceolaria sp.); no Cactaceae.  Discuss relationship between elevation, temperature and moisture availability, and plant growth forms and community types (e.g., paramo, puna).

Fauna (2h)

Classes of vertebrates: few fishes (limiting oxygen), Lake Titicaca Orestias sp. and Astroblepus sp., introduced trout; amphibians (specialized frogs, Telmatobius sp.), severe problem with amphibian decline; reptiles (Liolaemus sp. up to 5000m and active to 1oC); Birds (Condor, Andean Goose, Lapwings, Flamingo, giant hummingbird; mammals (camellids llama, alpaca, vicuna, guanaco, puma, chinchilla, guinea pigs.

Field work in Ecuador: 5 days

Coastal Ecology

Physical Oceanography (2h):  Physical characteristic of salt water and the oceans.  Currents principle oceanic gyres - impacts on adjacent land masses; isotherms, thermoclines; tides (spring/neap tides).

Productivity (2h):  Photic zone, aphotic zone, productivity and ecological process in both zones.  Phytoplankton base of food chains, zooplankton and temporarily larval forms; concentration over continental shelves.

Adaptations (1h): Nekton vs plankton: pelagic fishes, bottom dwellers. 
Disturbances and Conservation (2h):  Main problems of international waters; pollution; abuse of fisheries (fishes, pinnipeds, cetaceans, sea turtles) Maximum Sustainable Yield (MSY); Catch per Unit Effort (CPUE).

Coral reefs (2h):  Physical characteristics of the coral reefs; conditions for coral reef to develop; corals and the zooxanthellae; reefs diversity; physical and biological disturbances and conservation; keystone species; atolls.

Intertidal Zones

Physical factors (1): Temperature, radiation, water loss, wave action, intertidal stress, zones: supralittoral, infralittoral, sublittoral zone

Ecological processes (2h)  Particular circumstances of the intertidal zone and how it affects productivity, competition, and specializations of the species in the area; compact transition zones, high productivity, diversity, competition, specialization.

Adaptations (2h):  Resistance and resilience to high temperature fluctuation, resistance to dehydration, and changes in salinity;  behavioral mechanisms to cope with intertidal changes; euthermal, stenothermal/euryhaline, stenohaline;  dynamic of tidal pools; rocky shore colonization, competition for substrate space.

Fauna (2h): Porifera: sponges sessile, filter feeders; Cnidaria: corals, anemones sedentary; Mollusca: Polyplacophora, chitons, scrapers; Bivalvia: clams, filter feeders, siphon/foot specializations; clam harvest, local conservation strategy in Esmeraldas area; Gastropoda: snails, scrapers, predators, drills; Cephalopoda: squids, (gregarious social piscivores), octopus (solitary, primarily eat crustaceans); Annelida:  Polychaeta (sessile tube worms [Chaetopterus], errant predators [Nereis], plume worms [Sabellaria], sediment consumers [Arenicola]; Arthropoda: decapod crustaceans [shrimp, lobsters, crabs shrimp farming and lobster management], amphipods [scuds], isopods (roly-poly, pill bugs, sea roaches], Cirripedia [barnacles, goose-neck barnacles;  Echinodermata (pentaradial symmetry): Echinoidea (urchins, herbivores), Asteroidea (true seastars, predators), Ophiuroidea (brittle stars, filter feeders, scavengers), Holothuroidea (sea cucumbers, filter feeders, Galapagos harvesting). Estuarine ecology

Origin and Characteristics of estuaries (1h): Definition, different types of estuaries.  Physical variables: sedimentation, mixing of water, salinity fluctuation, temperature, oxygen; influence of the tides and the seasons in these variables

Ecological processes (2h): Productivity, cycling of nutrients, abundance and diversity (economic importance), zonation; salt water species, fresh water species and brackish water specialists, endemism.

Mangroves (2h):  Halophytic trees, different transition zones with low to no waves action but affected by tide fluctuation – intertidal.  productivity high, exportation of detritus high, importance as nursery shallow root systems, challenged by anaerobic soils and high CO2. Rhizophora red mangrove "viviparous" (Rhizophoraceae). prop roots  traps sediments to build land, often most seaward. Avicennia black mangrove (Verbaenaceae) "pneumatophores" tolerates higher salt concentrations and sandier soils, yielding an ability to colonize exposed shores Laguncularia white mangrove (Combretaceae).

Terrestrial Ecosystems

Physical characteristics (2h): High solar radiation, low moisture.  Climate Garua season, adiabatic cooling; the Chocó and its unique characteristics;  dry low elevation forest.

Ecological processes (2h): Particular circumstances of the low dry forest and how it affects productivity, competition, and specializations of the species in the area.  Productivity, high and seasonality, Nutrient cycling, soil fertility.

Flora (1h): Ceiba trichistandra; Cordia lutea; palo santo –Bursera sp.; cacti – Pilocereus sp., prickly pear – Opuntia sp.

Disturbance and Conservation (4h):  Shrimp farms, development of shores;  grazing and fire; major conservation problems in Ecuador: desertification, goat activity, little recuperation western side of southern continents.



Galapagos

Geologic History (2h):  Age and origins (hot spot concept); vulcanism:  structures (spatter cones, tuff cones, parasitic cones, lava tubes, lava types [aa, pahoehoe

Biogeography and Colonization (4h):  Island biogeography: time/distance/size, types of barriers, founder effect; timing and development of the ecosystem;  colonizing order (producers, then herbivores, then carnivores);  colonization of certain species with particular life histories (e.g., wind dispersed plants, no amphibians, few bats);  adaptive radiation, speciation of Opuntia and finches;  island tameness. 

Flora (2h): Lack of brightly colored flowers (few insect), commonalties with the continent, characters of dry coast, pre-adapted cloud forests on high islands (over-represented ferns, lichens, mosses, liverworts beans, grasses, asters, cacti); groups that are lacking (orchids, palms, mints, melastomes, bromeliads).

Fauna (4h): closest relatives; points of probable origin; no freshwater fish, no native amphibians; many reptiles due to endurance for colonizing conditions (Land Iguanas, Marine Iguanas, Lava lizards, snakes, Giant Tortoises); birds with special adaptations (boobies, cormorants, penguins, albatross, frigate birds, gulls, finches, hawk, mockingbird, flycatcher); mammals (sea lions, cetaceans); Problems: introductions (dogs, cats, rats, goats, donkeys, pigs, cattle, horses), control and management.

Conservation and disturbance (4h):  Over-use of fisheries, sea cucumbers, human demographic explosion, other conservation problems produced by humans; exotic species.

Field Work in Ecuador:  14 days

Rainforest Ecology

Geology and Origin (2h):  Plate tectonics, up lifting of the Andes; sedimentological origin and characteristics of the Amazon Basin; glacial periods; mud slides; formation of mesas and other catastrophic depositions; paleoclimate

Climate (2h): Seasonality, tropical convection, regional temperature, temperature profile in the forest and out of the forest, energy flow and the green house effect.

Ecological processes (4h): Particular circumstances of the rain forest and how it affects productivity, competition, and specializations of the species in the area; nutrient cycling; soil fertility; mycorrhizae. 

Soil formation (2h):  Weathering; soil texture: lime, clay, sand; soil structure; soils in the Amazon: texture, nutrients, leaching, Fabacea, Paradox of Luxury.

Rainforest dynamics and Distribution (2h): Definition and characteristics of Terra Firme, Varzéa, and Igapo.

River dynamics (2h): Flooding, seasonality, damming of smaller tributaries, run-off, oxbows, erosion; white water, clear water, and black water: characteristics, productivity and diversity.

Forest Structure (2h):  Leave composition, waxy coverage, drip points, profile, temperature and the stratification of the forest; plants adapted to sun and to shade; strata in a rain forest, Emergent trees; Size and shape of the canopy of the trees; light competition and its influence on the forest structure and life style.

Life style (1h): Vines, trees, epiphytes, hemi-epiphytes, understory, consequences of the light competition.

Tree falls (1h): Gaps, their origin and consequences: canopy interrupted. different conditions of heat, sun, moisture, wind, depending on the orientation of the gap; pioneer species and seral stages; similarities of the tree gap and the Conuco as an agricultural method.
 
Diversity (4h): Definition: evenness vs richness; hypotheses put forth to explain high diversity in the tropics: time stability hypothesis, predation hypothesis, productivity and resources, habitat heterogeneity, climatic predictability, gap dynamics, vicariance due to rivers and ridges isolating populations; refuges theory.

Herbivory (2h):  Herbivore trade-off: high abundance of food of low quality; changes in the nutritive value of leaves as they grow; optimum foraging theory.

Defense against predators (2h): Structural (slow to develop): carbohydrates, different kinds of carbohydrates (glucose, lignin and cellulose); hindgut vs foregut fermentation.  Chemical defense (quick to develop): secondary compounds (e.g., alkaloids); spices and drugs.  Chemical defense lowers the benefit of the item by increasing the cost of digestion. It can be perceived by other plants and produced as needed.

Arm races (2h): Examples of arm races between plants and herbivores; insect dealing with the drugs or using them for themselves; insecticides and the practical conflicts of fighting pests; top-down forces vs  bottom-up forces: representative examples of each.

Leafing (1h):  Synchronous vs asynchronic leafing; dry forests and satiation of predators; early leafing to avoid herbivory; leaf predators on rain forest invertebrates; Howler Monkeys; iguanas; Hoatzins; sloths; deer; tapirs; Garcia Effect. 

Flowering (1h):  Other than in emergents there is no wind fertilization so fertilization depends on animals; flowers appropriately colored scented to attract pollinators; humingbirds that cheat; other interesting examples of coevolution and arm races regarding flowering; non-synchronous flowering so there is food for pollinators year- around.

Fruiting (1h): Dehiscent, hooks, explosive, tasty fruits, fruit sizes that match the disperses (representative examples in birds of the families Citacidae and Craccidae);  protection of seeds; seed dispersal and seed predation.

Flora (2h): Representative species of plants of the rainforest

Fauna (2h): Representative species of animals of the Rainforest

Disturbances and Conservation (8h):  Relevant issues affecting the Amazon basin including gold mining, logging, development, human encroachment, hunting.

Field Work in Ecuador: 14 days