Simplistic predictions, confounding effects, and complex responses; climate tales from Archbold Biological Station Hilary Swain 1, Nancy Deyrup 1, Kye Ewing 1, Evelyn Gaiser 2, Reed Bowman 1 & Eric Menges 1 1 Archbold Biological Station 2 Florida International University
Archbold Biological Station founded 1941 data collection from 1931
Eric C. Grimm Illinois State Museum Research and Collections Center
2001 Higher summer temperatures, decrease in winter cold spells, shift north in frost line, earlier breeding for plants and animals Warming of lakes Increases in drought related fires
Maximum summer temperatures (J,J,A) 110 100 90 80 70 60 50 40 30 1932 1936 1940 1945 1950 1954 1959 1963 1967 1972 1976 1980 1985 1989 1993 1998 2002 2006 Maximum midwinter temperatures (D,J,F) 110 100 90 80 70 60 50 40 30 1931 1936 1940 1944 1950 1954 1958 1963 1967 1971 1976 1980 1984 1989 1993 1997 2002 2006
Summer minimum temperatures (J,J,A) 80 75 70 65 60 55 50 45 1932 1936 1940 1945 1950 1955 1959 1963 1968 1972 1976 1981 1985 1989 1994 1998 2002 Midwinter minimum temperatures (D,J,F) 80 70 60 50 40 30 20 10 0 1931 1936 1940 1945 1950 1954 1959 1963 1967 1972 1976 1980 1985 1989 1993 1998 2002 2006
Number of freeze days at Archbold 24 22 20 18 16 14 12 10 8 6 4 2 0 1934-1935 1940-1941 1946-1947 1951-1952 1956-1957 1961-1962 1966-1967 1971-1972 1976-1977 1981-1982 1986-1987 1991-1992 1996-1997 2001-2002 2006-2007 Archbold Temp change in relation to land use change- Marshall
Lake Istokpoga
Long-term climate trends in timing of breeding in Florida Scrub-Jays? Unclear - except breed earlier during La Nina Mean laying date (day of year) 105 100 95 120 110 100 90 80 70 1970 1975 1980 1985 1990 1995 2000 2005 el nino Year la nina all years supplemented not supplemented Reed Bowman Laying date 90 85 80 75 70 65-3 -2-1 0 1 2 3 4 Southern Oscillation Index (SOI) Reed Bowman
Marked land use effect on timing of breeding in suburban versus Archbold Scrub jays 1 March 1 April 1 May 1993 natural suburban natural suburban natural suburban natural suburban natural suburban natural suburban natural suburban 1994 1995 1996 1997 1998 1999 2000 natural suburban 30 40 50 60 70 80 90 100 110 120 130 140 First clutch initiation (Julian date) Reed Bowman
2001 Warming of lakes test using Lake Annie long-term datasets from Archbold 1983 2006
Lake Annie: decreasing temperature over time 12 Mo. Running Mean T (ºC) Mean Water T (ºC) 24 23 22 21 20 19 27 25 23 21 19 17 15 Air T Water T 1985 1990 1995 2000 2005 Surface Bottom 1985 1990 1995 2000 2005 Stage (FSL) Min Ann. 1% Light (m) 113 112 111 110 Groundwater Level Lake Stage 1985 1990 1995 2000 2005 110 111 112 113 0 Lake 2 Stage 4 R 2 =0.76 6 8 Groundwater 10 Level R 2 =0.78 124 128 132 136 132 128 124 120 Increased stage and groundwater height are associated with decreased transparency Gaiser et al in prep
80 70 Precipitation (Jun-Oct) Precipitation (Nov-May) 60 50 40 30 20 10 0 1932 1942 1952 1962 1972 1982 1992 2002 Annual rain above/below average (52.87") 30.00 AMO warm AMO cool warm 20.00 10.00 Inches rain 0.00-10.00-20.00-30.00 1932 1942 1952 1962 1972 1982 1992 2002
2001 Increases in drought related fires
Increasing fires in relation to drought? Archbold - acres burned annually 47% prescribed, 35% accidental, 18% lightning 800 700 600 500 400 300 200 100 0 Prescribed/Escape Prescribed Lightning Accidental 1967 1971 1975 1979 1983 1987 1991 1995 1999 2003 2007 Dry season rainfall driven by ENSO Dry season rainfall (inches) 40 35 30 25 20 15 10 5 0-5.00-4.00-3.00-2.00-1.00 0.00 1.00 2.00 3.00 Southern Oscillation Index
Prescribed fires acres in relation to drought KBDI 700 600 500 400 300 200 100 0 0 100 200 300 400 500 600 700 Acres Accidental fire acres in relation to drought KBDI 800 700 600 500 400 300 200 100 0 0 100 200 300 400 500 600 700 Acres Lightning fire acres in relation to drought KBDI 800 700 600 500 400 300 200 100 0 0 100 200 300 400 500 600 700 Acres
Climate change and plants Eric Menges In Florida, predictions of more variable climate NCEAS group: explore different types of variation and effects on stochastic growth rate (Morris et al. 2007, Ecol. Letters) 3 of 5 species in analysis from Florida scrub (data from Menges et al., ABS plant lab) Expectation from past studies: variation reduces stochastic growth rate
Positive elasticities for between-phase variance, especially for survival (left group of bars), for D. frutescens 0.1 0-0.1-0.2 Greater demographic variation between, rather than within time-since-fire phases Positive elasticities for between-phase demographic variance Implies adaptation to fire-driven disturbance regime Also implies that climate-change effects on plants will be mediated by effects on disturbance regime (e.g. will there be increased fire frequency given more variable climate?)
No good support for our simplistic predictions - plenty of confounding effects, and complex responses Land use change Wetland losses, urbanization AMO and SOI drivers Overwhelming drivers for intermediate (20-30year) and short term drought and flooding cycles Socio-economic responses - burn permits, FSJ supplementary feeding Recommend a return to Lake Annie for a detailed 2000+ year core to elucidate a decadal resolution climate record Team of researchers very interested in such an undertaking.