Tree Biology & Physiology Flashcards

What is the role of xylem in a tree?

Answer: Transferring water from roots to leaves

Xylem is one of the two main transport tissues in vascular plants, including trees. Its primary function is to transport water and dissolved mineral nutrients from the roots, up through the stem, and to the leaves. This upward movement is crucial for photosynthesis and maintaining turgor pressure within the plant.

What is photosynthesis in trees?

Answer: The conversion of sunlight into energy

Photosynthesis is the vital process by which green plants, including trees, convert light energy into chemical energy. Using chlorophyll, carbon dioxide from the air, and water from the soil, trees produce glucose (sugar) for food and release oxygen as a byproduct. This process is fundamental for tree growth and survival.

How does tree bark protect the tree?

Answer: Protects from pests and environmental damage

Tree bark serves as the tree's protective outer layer, shielding the delicate inner tissues from various threats. It acts as a barrier against insect infestations, fungal diseases, and physical damage from animals or weather extremes. Bark also helps regulate the tree's internal temperature and prevents excessive water loss.

What is the function of phloem in trees?

Answer: Transferring sugars and nutrients from leaves

Phloem is the other main transport tissue in trees, working in conjunction with xylem. Its primary role is to transport sugars (produced during photosynthesis in the leaves) and other organic nutrients to all parts of the tree where they are needed for growth or storage. This movement can be both upwards and downwards, depending on the plant's needs.

How do trees adapt to drought conditions?

Answer: Reduce leaf growth

Trees adapt to drought conditions by implementing strategies to conserve water. Reducing leaf growth, shedding leaves, or developing smaller, thicker leaves are common adaptations that minimize the surface area available for transpiration (water loss through leaves). This helps the tree retain precious water during periods of scarcity.

What is the primary function of tree roots?

Answer: Anchoring and absorbing nutrients

Tree roots perform two critical functions for the tree's survival. Firstly, they anchor the tree firmly in the soil, providing stability against wind and other forces. Secondly, and equally important, they absorb water and essential mineral nutrients from the soil, which are then transported to the rest of the tree.

What is transpiration in trees?

Answer: Releasing water vapor through leaves

Transpiration is the process by which moisture is carried through plants from roots to small pores on the underside of leaves, where it changes to vapor and is released into the atmosphere. This process is essential for pulling water up from the roots and helps cool the plant, but excessive transpiration can lead to water stress.

What is the impact of soil compaction on tree roots?

Answer: Reduces root oxygen and water absorption

Soil compaction, often caused by heavy foot traffic or machinery, reduces the pore space within the soil. This decrease in pore space limits the availability of oxygen for root respiration and impedes water infiltration and absorption. Compacted soil can severely stress tree roots, leading to poor growth and overall tree decline.

What is cambium tissue in a tree?

Answer: Active growth tissue

The cambium is a thin layer of actively dividing cells located between the xylem and phloem in a tree's stem and roots. This meristematic tissue is responsible for secondary growth, producing new xylem (wood) towards the inside and new phloem towards the outside, allowing the tree to increase in girth. It is the primary growth engine for the tree's diameter.