Seasonal Focus Lab: 3 rd Grade

Transcription

1 Seasonal Focus Lab: 3 rd Grade Emphasis: Form and Function as Adaptions to Environment Seasonal Focus: (Labs vary according to availability of fresh plant material. We may occasionally accommodate a requested focus of interest in a different season) Fall (September November): Seeds & Fruits Winter (December February, but suitable year-round): Drought Adaptations (leaves) Spring (March May): Flowers Learning Objectives 1. Students are able to identify basic plant parts and how each contributes to plant survival. 2. Students recognize that reproduction is essential for all organisms since it ensures their genes and traits are passed down to the next generation. 3. Students recognize that plants need soil, water, pollinators and sunlight to survive and live in places that support their needs. When the physical characteristics of an environment changes, some organisms need to adapt in order to survive. 4. Plants and animals can manipulate the environment they live in. 5. Children gain an understanding that humans depend on plants for food and resources and could not survive without them. Vocabulary Roots Stem Leaf Flower Pollination Habitat Adaptation Survival Trait Population Inheritance Seasonal Topics What s Blooming/Happening? Fall desert willow (early fall) devil s trumpet (datura) California goldenrod California fuchsia California buckeye seeds oak apple galls about to fall/dry out pollen and allergies! ferns releasing spores

2 Winter water in the creek (hopefully!) increased rainfall (greener landscape) Spring matilija poppy mallows California poppies coast live oak coast live oak fairy duster California buckeye fairy duster lupines Lab Focus: A few examples (if you would like more, please ask for additional resources) Seeds & Fruits (Plants have evolved many interesting ways to protect and disperse their seeds. A close examination of seeds and fruits often reveals how they are adapted to survive and travel. ) sweet acacia Students may notice that seed pods on sweet acacias resemble a green bean. That is because they are both legumes! When pods are developing, they are bright green, just like green beans. Over time they dry out, causing them to split down the middle. Unlike green beans, the rupture causes the seeds to fly out of their pod, scattering them all over the ground! toyon Bright red toyon berries are consumed by all kinds of California wildlife, including: American robins, mockingbirds, coyotes and more. Animals eventually drop the toyon seeds that are contained in the nutritious berries with their waste, enabling seeds to travel long distances from their point of origin. California buckeye Unlike toyon, which relies on its berries being consumed to spread, California buckeye trees contain toxins in their seeds, leaves, and stems that make them poisonous to eat. The toxins help keep the herbaceous parts of the plant safe, and ensure that seeds remain intact and able to survive through the long dry season. The round seeds are able to roll down slopes, and can travel only a short distance from the tree. Flowers (Wind-pollinated flowers are usually not very noticeable, but flowers that require animal pollination are often large and attractive, and often have relationships with specific animal pollinators. Which animal is the most likely pollinator for a flower can often be determined by a survey of flower characteristics.

3 The small, red, and tube-like flowers of are perfect for attracting hummingbird. The cylindrical shape of the flowers mirror the structure of hummingbird tongues and beaks, and red is known for attracting these tiny birds. orchids Orchids have some of the most specialized flower adaptations in the plant world, some with modifications so specific they can only be pollinated by a single species of insect! Fairy slipper flowers have yellow bristles that trick bumble bees into thinking they have found a nectar source; the bumble bees don t get any nectar, but they pollinate the flower. Mature bumble bees do not fall for this trick but it works exceptionally well on the young, inexperienced bees. Stream orchid flowers produce an aroma that smells like aphids, which are a food source for hover fly larva. To the orchid s benefit, flies inadvertently collect some of its pollen when they lay their eggs, however, sadly for the flies, the larvae perish without a source of food. iris Insects and other animals see colors differently than humans. Bees, for example, see in the ultraviolet spectrum, meaning colors that may look dull, or even invisible, to us can be incredibly vibrant for them. Plants use this to their advantage and have evolved nectar guides. These guides are lines, dots, or patterns that help point a pollinator towards their nectar reward, much like lights along an airstrip. While these may just look like designs to us (or even be invisible), for a pollinator these guides are vibrant neon signs leading them towards their rewards. While many flowers contain both male and female parts, some plants such as the California have separate male and female flowers. The male flowers resemble small red or brown balls, while the female flowers are small, yellow clumps that hang together like a bunch of grapes. Plants that produce both male and female flowers on the same individual have some advantages over plants that only produce either male or female flowers since both individuals are able to reproduce, rather than just the plants with female parts. They also don t rely on the presence of the plant of the opposite sex for reproducation. Leaf Characteristics (Although many plant parts demonstrate drought adaptations, they are most easily seen in various leaf characteristics) prickly pear cactus Spines on cactuses are one of their most defining features and are easily recognizable. Students may notice that cactuses lack what conventional thinking would call leaves. Spines are in fact modified leaves that have developed over time in order to protect the plant from consumption as well as safeguard the reserve of water stored in the succulent

4 stems. Succulent structures are generally either stems or leaves and are typically green, squishy, and moist. coastal redwoods Redwoods are some of the tallest trees, and organisms, found on Earth! Although our Garden redwoods aren t as tall as some of their giant relatives, redwood trees can grow hundreds of feet tall! Redwoods acquire water using their tiny, brush-like leaves that comb the skies for coastal fog. This has a lot to do with why our trees are smaller than ones you would find up North, since our region receives far less rainfall and fog. If you pinch a leaf of and smell your fingers, you will breathe in a sweet, strong scent. Unnoticeable with the naked eye, these leaves are covered with tiny droplets of oily perfume that give it this pleasant aroma. The scent helps attract pollinators as well as deter herbivores from snacking on it (the same way you wouldn t want to eat a salad if someone sprayed perfume on it). coast live oak vs. island oak Although coast live and island oaks may look very similar, their leaves have some defining characteristics that separate the two. These differences are closely related to the region in which they are located, and the associated climate. Coast live oaks, which are normally found in hot and dry conditions, have small, vertically-oriented, waxy leaves that help minimize sunlight exposure and evaporation. They also have small spikes at the tips of their leaves to help condense and collect water droplets that form from the coastal fog. Island oaks, on the other hand, receive more fog on a daily basis on the Channel Islands and don t require the same water-conserving traits. As a result, their leaves are flatter and smoother than those found on Coast live oak. s Sycamores can be found by stream beds and in riparian habitats where water is more readily available than nearby uplands. In general, there are typically more plants and a greater amount of shade in riparian areas. Since s are able to easily obtain water and sunlight, their leaves are horizontally-orientated, large, and flat to increase the chances of picking up sunlight where it seeps in through gaps in the above canopies. Manipulating the Environment 1. Animals can manipulate and change the environment in order to obtain needs for their survival. Plants are often times used in or affected by these changes. a. Ex: Acorn Woodpeckers hammer out holes in trees to store their food. i. These holes act as nest sites for organisms and entry points for bacteria and fungi that may eventually rot the tree. ii. Some trees are so badly drilled that it can compromise the infrastructure and cause it to break or fall down.

5 iii. Good example can be found on the telephone poll by the old Herbarium entrance. b. Ex: Oak galls initial purpose is to provide a safe place for wasp larva to grow but after they leave it can serve as a food source for other organisms c. Ex: Gophers and other burrowing animals can cause portions of hills to cave in, disrupting and potentially killing the above vegetation. 2. How do humans manipulate and change the environment? a. Deforestation, dams, building roads and homes etc. b. What sort of affects can these have on an environment?