Study Guide 2 Flashcards
Provide some descriptive traits for each of the following tropical plant families:
Annonaceae, Lauraceae, Myristicaceae, Orchidaceae.
Annonaceae: “custard apple fam” – cherimoya, soursop, pawpaw, lancewood, ylang-ylang — simple, flat, paired leaves w/ smooth margins — monolayered branches – radially symmetric flowers w/ 3 or 6 long petals —- big spiked, indehiscent, pulpy fruits (some cauliflorous) — flowers and fruits with fragrant oils — fruits and leaves with toxins
Lauraceae: “laurels” — trees, shrubs, and parasitic vines of Cassytha — top 5 in # of spp in single forest — cinnaomn, camphor, bay, avocado, rosewood — used in marine vessels — important for frugivores — thick, dark leaves with veins — small yellow/white/green flowers – big, single seeded drupe fruits that’re indehiscent — toxic sap or aromatic oils that’re resistant to insects
Myristicaceae: “nutmegs” — trees and shrubs — pantropical lowlands – medium sized trees – unknown origin, but maybe Africa/Madagascar 125-94 mya — glossy, dark green, simple leaves – almost no petals on flowers – fruits are big single seed with bright colors–aril — red sap and aromatic oils and hallucinogenics
Orchidaceae: epiphytes, lithophytes, hemiparasites, holoparasites —- biggest flowering plant fam — includes vanilla and is often cultivated as hybrids — monocots with variable growth forms – super modified resupinate flowers, bilaterally symmetric with one dif petal – tiny, wind dispersed seeds – symbiotic with fungi
What do we mean by a “megafaunal dispersal syndrome”? What plant families contain
species with this type of dispersal and in the absence of large, extinct animals, which
tropical birds or mammals contribute to dispersal in these species?
-big fruit grows on or close to trunk or on large branches –> inhediscent with thick or hard endocarp - hard to separate from pulp - drops on or before ripening —> bitter, peppery, nauseating chems –> seed benefit from or require physical/chemical abrasion to germinate
- Laurels, Anaceae
- oilbird, umbrellabird, pigeon, hornbill
Explain some differences in growth patterns or adaptations of early and late
successional tropical plants. Give examples of plants that you might find in early versus
late successional tropical forests.
Early
- Seeds: phytochrome pigment – photoblastic and thermoplastic – small, many, produced continuously – orthodox
- Seedlings: can’t survive in shade – grow fast with low branching
- Trees: often indeterminate (no resting buds or shoots and can make new brannches yr round) – leaves are short lived with high turnover and are soft with few chems
- Solanum and cecropia
Late
- Seeds: germinate below canopy – recalcitrant (non-dormant, no seed bank) – bigger and made less frequently
- Seedlings: shade tolerant; slow growth; lots of branches
- Trees: Determinate branching (resting buds and phases of growth) – leaves are tough and have chems – slow growth – long life
- pretty much everything from 1st notecard
Outline some of the differences in the traits that tropical fruits, seeds, and flower
possess that make them different from the types of fruits, seeds, and flowers that we
see in an average temperate forest plant. Summarize the differences in rates of growth
or length of lifespan between temperate and tropical trees.
Flowers: rely on animal pollination, have adaptations to promote outcrossign – vary from generalized w/ many pollinators to specialized w/ co-adaptations – big, conspicuous, nectar rich, away from leaves
Fruits: cauliflaury – strong flavors and aromas to attract animals
Seeds often inhedicent and need animals for physical or chemical breaking –> often big single seed
Tropical trees have faster growth rate (sunnier, warmer, wetter climate), but lower longevity
Describe the general characteristics of soils in an average lowland tropical rain forest.
What two types of soils occur in the majority of tropical rainforest regions?
Nutrient poor, highly weatherd , good for holding water bc clay-y, acidic bc of H ions in rain
Oxidols (35%)
- excessively weathered, clay soils w/ no more than 10% minerals – high phosphorus retention by oxides
- orange/yellow due to iron and aluminum oxides
- occur in forest with flood seasons
Utisols (28%)
- super leached, acidic soils w/ no more than 10% minerals (no Ca) – <35% base saturation, pH <5
- dark red/purple/orange due to iron oxides
- in aseasonal forests with consistant downward water flow
In what types of locations would you find inceptisols and andisols and how do these 2
additional tropical soil types differ from the average soil in a lowland tropical forest?
Andisols = very fertile, volcanic ash in Hawaii and Andes
Inceptisols = form quickly where plant biomass is decaying (floodplanes bring nutrients) in New Guinea
How do soils in peat forests in South East Asia differ from those mentioned above? Why
is it still difficult for plants to absorb nutrients from these soils?
Histosols are infertile peat areas that’re heavily organic with accumulated humus –> not available to plant roots because it’s held above the level of the water tables
What is meant by the phrase “paradox of tropical luxuriance” or the “paradox of the
plants”? Can you explain how highly diverse and dense tropical plant communities occur
on nutrient poor soils?
It references the seeming inconsistancy of the huge biomass and diversity of tropical rainforests despite the nutrient poor soil
Fertile soil is found in the canopy
plants can recapture dissolved nutrients as they’re released by decomposition
-Nutrients released from weathering of substrate (bedrock, volcanic eruptions, dust storms)
-Nutrients in water (throughfall, stemflow, capillary action, rain/humidity)
-Nutrients in biomass (greenfall)
-Nutrients in necromass (litterfall, waste, dead animals)
List and describe some adaptations that tropical plants in particular or tropical forests in
general exhibit for capturing nutrients before they are leached into the soil.
high shoot to root ratio
- apogeotropic roots grow up onto other plants (5-6 cm/ 72 hr)
- canopy roots = adventitious roots that grow into epiphyte layers and aerial soil
Leaves
- retain nutrients longer and use them efficiently
- thick leaves so don’t lose to herbivory
- waxy leaves/drip tips prevent leaching
- great at carbon fixation
- long life
- big, so catches rain
Throughfall and stemflow
Epiphytes, epiphylls, and phytotelmata contribute to arrested litter
How do animals contribute to rapid recycling of nutrients, soil mixing, or addition of
nutrients to soils?
- Lots of soil organisms
- Microflora (mycorrhizae) associated with 95% of plants –> fungi gives nutrients and gets prots, carbs, and fats –> increases surface area uptake, gives access to P and iron oxides and Ca and K
- Macrofauna: beetles, ants, caerpillars, millipedes, isopods, annelids, spiders, centipedes = litter transformers –> termites (isoptera) = 75% insect biomass and 10% of tropical animal biomass (eat 20-50% fallen leaves) (assist in N P Ca and K) (aerate soil)
herbivory leads to rapid recycling of nutrients
Outline some differences between temperate and tropical bird communities.
- Greater diversity bc of stratification
- less proportion of insectivores (60 vs 90% of breeding season birds) – unique ant birds though
- more diversity of canopy birds bc of fruit
- Migration: tropical birds don’t do this
- lower basal metabolic rate
- longer lived, fewer offspring
for each of the following taxa, list the major tropical region in which it occurs and provide a description and a unique characteristic that distinguishes it from other birds: Cassowary Hummingbirds Parrots Toucans & Hornbills Trogons Cotingas Antbirds Kingfishers Tyrant Flycatchers Oropendolas Vangas Motmots Leafbirds Sunbirds
Cassowary = Australia and New Guinea –> live up to 50 yrs –> ground dwelling –> long spike toe for defense –> bony crest on head – no camoflauged eggs (green) –> quills
Hummingbird = nectivores, Neotropical, related to swifts in Apodiforms –> small with thin bills and bright feathers –> feed by hovering –> can fly backward –> 90% nectar, but some isects –> territorial and trap-lining
Parrots = global distribution, but mostly in SA and Australia –> shork, thick, hooked upper bill –> 2 backwards claws –> nest in tree cavities and clffs –> seed predators and frugivors (a few nectivores) – parakeeets eat dipterocarp seeds
Toucans/Hornbills = long, dep bills for feeding, display, and defense –> cavity nester who seal nests –> mostly frugivres but will eat lizards, snakes, birds, and sometimes insects –> toucan is neotropical, but Hornbill is in Africa and Asia
Trogon = neotropical –> bright, compact, long tail, short notched beak with serrated mandible –> weak legs with backward claws –> frugivores, but also insectivores and eat lizards
Cotingas = Neotropical –> bigest range of body size –> short hooked beaks, round wings, strong legs–> terrestrial and courthsip behaviors –> extreme frugivores
Antbirds = Thamnophilidae, grallariidae, formicariidae –> neotropics and africa –> big variation in size –> strong bills with notch and small tooth, long claws, strong legs –> follow swarming ants and consume “flushed” insects
Kingfishers = “alcedines” –> origin in NA, but mostly Africa and Australia (a few SA) –> riparian habitats –> big heads, long beaks, egg-shaped eye –> burrow nesters –> insectivores and eat frogs/fish
Tyrant flycatchers = tyrannidae –> NA and SA –> small to medium with dull gray to yellow color –> hawking= catch insects in flight
Oropendolas = Icteridae = neotropical –> big, yellow tail, dark color with contrasting bill –> colonial breeders (10-50 nests) –> make long woven basket nests in high open canopies –> insectivores, frugivores, granivores, nectivores
Vangas = Madegascar –> super diverse –> look like a bunch of different birds to fill all the niches in Madegascar
Motmots = neotropical –> fused outer and middle toes –> serrated bills, long racquet tails –> burrow nestrs in groups of 20 couples –> insectivores, faculatative frugivory, predators on snakes and lizards
Leafbirds = Chloropseiae = 1 spp in SE asia –> sexually dimorphic w/ green feathers –> protect flowering trees –> song mimicry, insectivore and nectivore
Sunbirds = Africa, asia, new guinea, australia –> Nectariniidae (Africa and se asia) w/ elongated, curved bills, split tongues, and strong legs –> meliphagidae (new guinea and australia) w/ thick bills, boring color, hang upsidedown –> nectivores and frugivores
Compare and contrast nectivory, frugivory, folivory, carnivory, and insectivory in birds,
bats, and mammals. Specifically, explain some of the benefits or downsides of each
mode of feeding and some morphological adaptations relevant to each.
Nectivory: nectar is easily difestible, but doesn’t have lipids or prots –> most nectivores eat insects too and will feed on sap in lieu of flowers –> have to hover sometimes
Frugivory: fruit is abundant and easily collected –> prolonged nesting time for fledglings –> bird adaptations to fruit eating = increased olfactory senses, above ground nesting, reduced clutch size, and extensive courtship displays –> mostly bi-parental care and feed insects to young –> extreme nest builders
Insectivores: Insects are high in fat and protein –> abundant, but difficult to catch –> can increase tree growth by 30% (more for canopy than understory)
carnivory: gape-limited –> require adaptations for catching, gripping, and shredding prey –> forward facing eyes for binocular vision –> sharp, hooked beaks (tomial tooth = uper notch on beak that assists in ripping prey) –> sharp talons (hallux = longer than other claws)
. How do the differences in feeding behavior (hovering vs. perching) between
hummingbirds and sunbirds & honeyeaters, as well as in the fruit feeding and pollinating
bats, contribute to difference in flower morphology between Africa and South America?
In neotropics, flowers are outside foliage –> trap-lining and territoriality reduce cross pollination –> hummingbirds pollinate small herbs, lianas, epiphytes
In Africa + Australia flowers are inside foliage –> generalist feeding and greater omnivory increase cross pollination –> sunbirds and honeyeaters pollinate bigger herbs, lianas, and epiphytes and trees
Describe some of the behaviors involved in courtship in frugivorous birds. What
hypothesis have biologists proposed to explain why these behaviors are unique to
extreme frugivores?
they have a high level of resources and are not strained energetically
fruit = high energy resource that’s available year-round
Sometimes dance by themselves, but also do lekking where a group of males go to specific dance location to attract females
