Presentation on theme: "NERDS 2012 Pre-Session #1 Content Lecture: Terrestrial and Aquatic Ecology Dr. Jennifer Hollander Dr. Jeffrey Baguley."— Presentation transcript:
NERDS 2012 Pre-Session #1 Content Lecture: Terrestrial and Aquatic Ecology Dr. Jennifer Hollander Dr. Jeffrey Baguley
Outline Climate and Life Zones of the Sierra Nevada Plants – Gymnosperms – Angiosperms Animals Plant-Animal Interactions Aquatic Organisms
Basic physics of the atmosphere Rule #1 – Warm air holds more water Rule #2 – Warm air rises, cold air falls Regional climates are determined by a combination of factors, most of which are influenced by these rules.
Gymnosperm Characteristics “Naked seed” – seeds mature in cones Found primarily in the Northern Hemisphere Conifers (largest Gymnosperm group) and Ephedra have modified leaf structures and can carry on photosynthesis in the winter (no leaves to drop)
Angiosperm Characteristics Flowers! – The function of the flower is to ensure fertilization of the ovule and development of fruit – Angiosperms are often classified based on their flowers (shape, number of petals, etc.) Fruit – Ovary which encases the seeds – May serve to attract dispersers
We will talk about specific species of animals during the second pre-session Today we are focusing on the bigger picture, and groups of animals that are involved in dispersing seeds of forest plants
Order Rodentia 40% of all mammal species Characterized by two continuously growing incisors in upper and lower jaw – Kept short by gnawing
Squirrels Sciuridae ( Spermophilus or Ammospermophilus ) Small to medium sized rodents found worldwide Live in almost every habitat Mostly eat seeds, however some squirrels are known to be omnivorous at times
Chipmunks Sciuridae ( Tamias or Eutamias ) Small, striped mammals in squirrel family All species (except one) are found in N. America Omnivorous, but collect and store seeds for winter us
Community Ecology In ecology, a community is a group of two or more populations of a different species Community ecology study the interactions between species in a community There are many different types of species interaction, including some that involve multiple species
Some types of species interactions Competition – species may compete with each other for finite resources Predation – using another species for food (not always “hunting” them) Mutualism – an interaction between species in which both species benefit Parasitism – one organism benefits (the parasite) at the expense of the other (the host)
Seed caching resulting in dispersal Seed caching animals disperse seeds by storing them for winter, and then “forgetting” to retrieve them. The seeds must be placed in a microsite conducive to germination and emergence.
Watersheds The entire land mass that drains into a given stream or river system. The Feather River watershed includes catchments for the various tributaries of the Feather and Yuba Rivers.
Terrestrial/Aquatic Commonalities Every living organism needs to eat something. – Photosynthesis fuels the food webs Every living organism needs to reproduce. Organisms will interact with each other in multiple ways. – Competition, predation, symbiosis, etc. While some organisms are exclusively aquatic or terrestrial, others depend on both habitats.
Bacteria & Cyanobacteria Unicellular prokaryotic organisms Bacteria are important decomposers and recyclers of organic and inorganic wastes Cyanobacteria may be important for photosynthesis, but blooms may also be an indication of poor ecosystem health.
Protists Unicellular (and some multicellular) eukaryotes Some are photosynthetic Some are heterotrophic Some mixotrophic
Phytoplankton and Benthic Microalgae Euglena Diatoms Crysophytes Dinoflagelates
Plants & Macroalgae “Macrophytes” There are several types of freshwater aquatic plants that are an important source of photosynthesis and also habitat in aquatic ecosystems. Macroalgae are multicellular protists (not plants)
Phylum Platyhelminthes “Flat worms” – Acoelomates – Mostly free-living – Mostly marine – Some freshwater – Some parasitic A freshwater turbellarian
Phylum Mollusca – Includes snails and slugs, oysters and clams, and octopi and squids Most mollusks are marine – Though some inhabit fresh water and some are terrestrial In freshwater habitats you will find: – Gastropods (snails) – Bivalves (clams & mussels) Phylum Mollusca
Gastropods About three-quarters of all living species of molluscs – Belong to class Gastropoda
Bivalves Molluscs of class Bivalvia – Include many species of clams, mussels, etc. – Have a shell divided into two halves – Suspension (filter) & deposit feeders
Phylum Annelida Annelids are segmented worms Annelids – Have bodies composed of a series of fused rings
Oligochaetes Oligochaetes (class Oligochaeta) – Are named for their relatively sparse setae, or bristles made of chitin – Include the earthworms and a variety of freshwater and marine species
Leeches Members of class Hirudinea – Are blood-sucking parasites, such as leeches Figure 33.25
Phylum Nematoda The round worms Ubiquitous – found everywhere – Marine, freshwater, terrestrial, some even live in polar ice. – It has been said that if you eliminated all of the structure on the earth, but left the nematodes behind, you would see a grey shadow of that structure. 1,000,000+ species estimated globally
Phylum Arthropoda Probably the most successful phylum of all animals – Approximately 10 18 – 10 19 individuals – 2,000,000+ species (insects and crustaceans account for most) Two out of every three known species of animals are arthropods Members of the phylum Arthropoda are found in all of Earth’s habitats
General Characteristics of Arthropods Arthropods are segmented coelomates that have an exoskeleton and jointed appendages The diversity and success of arthropods – largely related to their segmentation, hard exoskeleton, and jointed appendages
Insects Subphylum Hexapoda, insects and their relatives – Are more species-rich than most other forms of life – Live in almost every terrestrial habitat and in fresh water
Crustaceans While arachnids and insects thrive on land – Crustaceans, for the most part, have remained in marine and freshwater environments Crustaceans (subphylum Crustacea) – Typically have branched, appendages that are extensively specialized for feeding and locomotion
Decapods are all relatively large crustaceans – And include lobsters, crabs, crayfish, and shrimp
Invertebrates Come in All Sizes Meiofauna Macrofauna Megafauna 0.063 mm – 0.5 mm Live on surface or within sediment, small enough to live between sand grains 0.5 mm – 5 cm Live on surface or burrow within sediment (most are less one centimeter). 5 cm, easily see with naked eye