Distribution and abundance Glacier lily – flowering plants seem to do best where the soil surface is very rocky. Something about rock that favors glacier lily. Life history: iteroparous, long resource accumulation phase in an underground corm. Seeds stage – primary seed dispersal distance. Results – modal dispersal distance about 20cm Secondary dispersal by ants, present in other Erythronium species– elaiosome, full of elaios acid that is attractive for ant because of protein, then they through it out with seeds, which is better dispersal and a lot of nutrients in the soil in the ants garbage that favors the growth of the lily Seed germination experiment What factors about soil may influence on success of seeds. Deeper soil areas will contain more moisture compared to the rocky. Buried in organic soil made it, others not. Results of experiment suggest the opposite of what we saw: should find more plants away from thin soil around rock outcrops Should find most seedlings near flowering plants -
How to quantify gopher activity – leave cores of soil in the spring Flower vs vegetation vs seedlings
Rockiness vs soil moisture
Rockiness vs gopher activity
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Most seeds are produced in rocky areas and fall there but most die Few seeds that reach moist, deep-soil area are more likely to survive and produce seedlings But seedlings that get established in deep-soil have a risk to be under predation of gopher Rock-refuge hypothesis
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Desiccation due to abiotic conditions and stress, cant happen a lot, because flowers are there
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Delayed interoparity brings vulnerability
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Predation – species interactions
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Lily realized niche
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Why no elaisome – dispersal is a disadvantage
Cantor, Whitham: pocket gophers as an influence to the aspen trees. Trapping gophers at aspenmeadow interface allows aspen to invade the meadow. Removed gophers -> a lot of new stems in those
areas without gophers, when gophers are moving through the soil are cutting the roots influencing aspens growing -
Aspen grow better in deep-soil areas but only if protected from gophers Aspen clones are centered on rock outcrops; outward expansion is limited by gophers cutting roots, rock-refuge effect again Gophers have a profound effect on the habitat it leaves in, are keystone species in the aspenmeadow mosaic; direct – effect on the lilies, - effect on the aspen -> + effect on lilies
Climate change -
Co2 and methane: atmosphere is warming and can hold more water Hadley cells get stronger and larger, contain more water: desert belts shifting poleward beyond 30 degrees Local climate changes are affecting organisms Geographical ranges are shifting to match ranges of tolerance, a lot of animals migrate from higher
Eg. Polar bear is endangered species, because arctic snows melt fast, migrate to south -> hybridize with grizzly bears Eg 2 – Pika adapted to cold mountain tops, death zone for pika is in the lower part of the mountain Extirpation – local extinction