Presentation on theme: "SeaCliffs, Vegetation, and Birds Lecture 2. SeaCliffs, Vegetation, and Birds Hard rock cliffs Resistant bedrock (geology) Also, Soft rock cliffs Unconsolidated."— Presentation transcript:
Hard rock: change is slow over time Soft rock: sudden, often large- scale change due to mass movement Cross-sections of Sea cliffs vary dependent on nature and resistance of the rock, aided by jointing and mineral makeup, processes of weathering, exposure to wind, rain and sea salt, and erosion through undercutting at the base Two examples: (1) hard rock (2) soft rock
SeaCliffs, Vegetation, and Birds Vegetation on Hard rock cliffs depends on slope, depth of soil, presence of ledges (terraces), exposure to wind, rain and salt spray, as well as acidity of soil determined by the parent material (rock) Exposure to oceanic swell, onshore winds, and storms leads to maritime vegetation Inland vegetation changes because more sheltered e.g. from salt spray In less exposed areas then dependent on acid or alkaline rocks/soils then may get acid grasslands and heath versus calcareous grasslands (chalk and other limestones) Less exposed cliffs may have scrub and woodland communities Often vegetation transitions (e.g. due to salt spray) If isolated (and free of human activity) then endemic species (intolerant of competition) e.g. Limonium spp.
SeaCliffs, Vegetation, and Birds Dependent on the degree of slope movement then may or may not have vegetation or animal life In very open areas then may be invertebrate life Where less movement then may have woodland, scrub and grassland Landslips lead to exposed soil/rock Succession of plants if fairly stable for a period of time Ephemeral plants and invertebrates Major cliff falls can lead to woodland if stable Ephemeral refers to plants that are short- lived, grow and reproduce rapidly. Ephemeral soils are those develop quickly and disappear in short term cycles (Doody – Habitat Guide)
SeaCliffs, Vegetation, and Birds Exposure to wind, salt spray is a major determinant of vegetation communities Also, climatic effects Vegetation contains plants (and animals) that are mostly confined to coastal fringe Salt tolerant: Sedum rosea, Festuca rubra, Armeria maritima, Silene uniflora Halophytes: Crithmum maritimum, Limonium binervosum, Salicornia spp May also be some invasive species e.g. Carpobrotus edulis Etc…… See handout See http://www.habitas.org.uk/http://www.habitas.org.uk/
SeaCliffs, Vegetation, and Birds Sea Cliffs provide breeding and nesting for many birds Location e.g. ledges/burrows provide food source and protection Guillemot (Uria aalge) Razorbill (Alca torda) Kittiwake (Rissa trydactyla) Shearwater (e.g. Manx Shearwater Puffinus) Puffin (Fratercula arctica) Etc…… See http://www.birdguides.com/http://www.birdguides.com/
SeaCliffs, Vegetation, and Birds http://www.oursouthwest.com/Wild_Hab/Coast%20and%20Marine/Sea%20cliff %20and%20slope/seacliff.htm