Plant Ecology - Exam 2 - Growth and Reproduction

Lecture 10

How would you expect plant growth and survival to vary in response to warming climate across species range?

Reich and Olesky studied Scots Pine and found that in Northern populations survival and growth improves as zone moves northward. In Southern populations, survival and growth deteriorates as zone moves north mainly due to temperature.

What are the three patterns of plant resource allocation that we discussed in class? How would you expect these allocation patterns vary between a desert and a temperate deciduous forest? Annual & perennial plants?

Plants allocate energy to either maintenance, reproduction, or growth. the three patterns of 1. plant resource allocation are equally divided among the three over the plant’s lifetime, 2. growth and maintenance in early life before transitioning to mostly reproduction later, and 3. mostly maintenance and growth with no energy towards reproduction until one short period. Desert plants likely use pattern 3 while a temperature deciduous forest would likely use pattern 2. Annual plants like use pattern 1 while perennial plants likely use pattern 2.

Describe/explain Raunkaier system of plant form classification?

The Raunkiaer system of perennial growth form classification is based on the position of buds or regenerating parts of a plant. The four categories are phanerophytes, trees or tall shrubs with buds more than 25 cm above the ground; chamaephytes, shrubs with buds less than 25 cm above the ground; hemicryptophytes, perennial herbs with buds at the ground surface; and cryptophytes, perennial herbs with perennating organs below the ground surface.

Contrast the two forms of plant clonal growth.

The two forms of plant clonal growth are phalanx and guerilla. Phalanx have ramets that are spatially clumped while guerilla have ramets that are dispersed in space.

Discuss the difference between phenotypic and adaptive plasticity.

Phenotypic plasticity is the immediate response to the environment and may not be transferred to the next generation. Adaptive plasticity is the consequences for fitness and genetic makeup of future generation.

Illustrate with the example from class how one species can drive adaptive plasticity in another species.

When the creeping spearwort and the creeping bentgrass are grown together (competition present), the spearwort had a higher stolon internode angle and had a shorter stolon height compared to when it was grown alone.

What is plant phenology and what does it respond to?

Plant phenology is the timing of plant reproduction and growth during a year. It responds to seasonal changes like temperature, moisture availability, wind regime, population dynamics of pollinators/seed dispersers/herbivores, and masting.

What vegetative modes of reproduction are there in plants?

stolons (stem that runs along the ground), rhizomes (underground horizontal stems), bulbs (underground rosette stems adapted for nutrient storage), root suckers (buds on near-surface roots), clonal fragments (pieces of plant break off), and bulbils (bulblike organs in leaf axils and inflorescences)

What are the allocation trade-offs between (a) animal & wind pollinated plants and (b) plants with seeds dispersed by wind vs. those dispersed by animals?

a. animal pollinated-more allocation towards making attractive/ large flowers, scents, pigments, and nectar. wind pollinated- less allocation into petals and sepals, more allocation into abundant pollen. b. wind dispersal- lighter grains go further from parent (better survival) but are smaller (lowers chances of fertilization) animal dispersal-beneficial for moving seeds away from parent but must accomplish seed dispersal while avoiding seed consumption.

What are the ways by which wind-dispersed seeds can accomplish long distance dispersal? Are there any tradeoffs there?

Long distance dispersal can be accomplished through small seeds and advantageous seed morphology (ex. helicopter seeds). The tradeoffs are that many seeds will be wasted due to dispersal to unsuitable habitats.

How does plant height and size of seed crop affect the ability of wind dispersed seeds to reach far away from the maternal plant?

greater plant height and greater seed crop allows farther dispersal of seeds from the maternal plant.