LANDSCAPE ECOLOGY SREM 3011 LECTURE 3 Dr Brendan Mackey Department of Geography The Australian National University
LANDSCAPE ECOLOGY SREM 3011 LECTURE 3 Dr Brendan Mackey Department of Geography The Australian National University
Framework for analysing plant and animal distributions? stochastic versus deterministic processes? forcing functions/response functions generic set of environmental forcing functions? generic scale(s)of analysis? in situ versus ex situ observations
Framework for analysing plant and animal distributions? stochastic versus deterministic processes? forcing functions/response functions generic set of environmental forcing functions? generic scale(s) of analysis? in situ versus ex situ observations
Aspects of env ironmental variables that have been considered in vegetation studies and their principal effects on plants(modified from Billings 1952) A Radiation regime; B Temperature or energy exchange regime; C Nutrient regime; D Water regime E Living regime in time or space or factors controlling plant responses (After Scott 1974) VARIABLES ASPECTS PLANT REGIME CL工MATc Radiation solar Spectral composition, intensit.e> direction, duration, periodic terrestrial 工 ntensity lntegration Temperature: Degree, periodicit ntearatlon lateral vertica variatio? E.D. 2 sOil Degrec periodicity 1ater i E vertcal variation free?@ thaw phenomena Ⅴate工 vapour Amount or densities, vapour pressures s vp deficits, evaporator. transparant⊥on condensed water Cloud, fog, dew, salt Bxec1p⊥ ta tlon amounts, frequencies droughts snowcover, now abrasion Content, tensions pply rat ae工t1O atmospheric gases: CompOS⊥tion oxygen carbon dioxide contents and partial pressures, ozone, pollutant C E B￥ essurE weather phenomena, gas partial p上 essures h,B,D,C wind Frequency, force, direction vaporation, abrasive agents
Aspects of environmental variables that have been considered in vegetation studies and their principal effects on plants (modified from Billings 1952) A. Radiation regime; B. Temperature or energy exchange regime; C. Nutrient regime; D. Water regime; E. Living regime in time or space or factors controlling plant responses. (After Scott 1974) VARIABLES ASPECTS PLANT REGIME
VARIABLES ASPECTS PLANT REGIME EDAPHIC Parent material Minerals present, structure weathering susceptibility physical PxO王五e, struCturE, texture proPerties ca analysis, soil moisture stabi1⊥ty chenical Clay mineralogy, organic compounds properties reakdown xchange nut卫卫ents toxicity elements- 上 otic properties s。i1f主x humus rates,ant五be GECG RAPF工c P。 sator: Work through other factors,e-g ngitude, etc ciate erosion Topography s1。pe asPect, ork through other factors,e·曰 a1tit日ae climate erosion Vicar,is t hermal effects mechanical Ash cover1ava flo PxR互C Climatic Tem eratur (air ntest climatic efects burning micro EA;h主 structon 〗nexa1 releasc, erosion Batac Community compos⊥t⊥On BIT工C other plants c。 petitor F。x1ght water 6 nutrents,an七主 biotic er ayt。 toxiC E王ects dependen 工,ttex&h physical chemical e￡ fects,cc 入,B,C,D,E An⊥ma1s destruct飞e Grazing, feeding,etc effect on soil bene王icia1 Nutrient cyo1五rg,xu seed d⊥ sperSs1 can change almost any factor,at t locally A,B,C,D,E
VARIABLES ASPECTS PLANT REGIME
Examining physical environment in terms of plant response: what role does variablelattribute play in controlling either 1. The distribution through space and time and/or 2. The availability to plants of: temperature radiation water nutrients
Examining physical environment in terms of plant response: what role does variable/attribute play in controlling either: 1. The distribution through space and time and/or 2. The availability to plants of: - temperature - radiation - water - nutrients
Primary Environmental Regimes 1. Radiation 2. Thermal 3. Moisture 4. Mineral nutrient
Primary Environmental Regimes 1. Radiation 2. Thermal 3. Moisture 4. Mineral Nutrient
SCALE PROCESS CO-L o insulation controls primary energy inputs to climate and weather patterns ES。 prevailing weather system controls longterm mean eelevation-driven lapse rates monthly climate e geological substrate-, exerts control on soil chemistry e surface morphology controls catchment hydrology slope, aspect, horizon shading-, controls surface ins。| ation egetation can。py -controls light, heat, water or understorey vegetate。n, structure and plant→> nutrient conservation and storage physiognomy NAN. soil microorganisms- control nutrient recycling
Two Landscapes ※ MESO A Shaded 1B Exposed Low radiation High radiation 2A Shaded 2B Exposed 1A and 2B experience similar radiation levels
Two Landscapes 1A Shaded 1B Exposed Low radiation High radiation 2A Shaded 2B Exposed 1A and 2B experience similar radiation levels 1. 2. MESO
Delivery of primary environmental resources places that look different to humans may 'deliver'the same level of primary environmental resources processes controlling resource delivery vary in their temporal delivery(eg seasonal and year-to-year variations) some contributing environmental factors are temporally stable(eg topography)
Delivery of primary environmental resources places that look different to humans may ‘deliver’ the same level of primary environmental resources processes controlling resource delivery vary in their temporal delivery (eg seasonal and year-to-year variations) some contributing environmental factors are temporally stable (eg. topography)
Biotic feedbacks/regulation? biota plays a critical role at micro-and nano-scales but feedbacks occur at all scales especially meso-and global at larger scales effects are due to the longer-term, agglomerative impacts of the biota(eg catchments, Earth)
Biotic feedbacks/regulation? biota plays a critical role at micro- and nano-scales but feedbacks occur at all scales, especially meso- and globalat larger scales, effects are due to the longer-term, agglomerative impacts of the biota (eg. catchments, Earth)