Heterogeneity In Urban Ecology. Heterogeneity in Urban Ecology. Collaborators 12/8/16. Steward T.A. Pickett. The City, The Forest, and the Trees

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1 Heterogeneity In Urban Ecology Steward T.A. Pickett Heterogeneity in Urban Ecology The City, The Forest, and the Trees Collaborators J. Mrogan Grove, USDA Forest Service Jarlath O Neil-Dunne, Univ. Vermont 1

2 Table of Contents Scope of urban/city Examples of heterogeneity patchiness Urban trees assessing opportunity Heterogeneity change through time Multiple roles of trees Urban City Suburbs Exurbs Cities as Inclusive Urban City Suburbs Cities as Inclusive Exurbs Regional systems 2

3 Why heterogeneity important? Part of ecosystem function Heterogeneity and Urban Ecosystem 3

4 Example Urban Heterogeneity Watersheds A B Figure 20. Land use (AP) and long-term sampling stations (B) in and 4

5 Rain Gardens Rooftop Connectivity 100% 75% 50% 25% 0% Socio-Cultural-Economic Template Human Behavior Riparian Revegetation 4 Human Outcomes External Drivers 5 Riparian Management Strategy 4 1 Events Pulses Flooding Presses Urban Watershed Land Cover Ecosystem Services Expected Nitrate Retention Expected Geophysical and Infrastructural Template Community Structure 1 Riparian Structure 1 2 Ecosystem Function Denitrification 3 Cadenas s o et al A B BASELINE CONNECTIVITY SINGLE-FAMILY CONNECTED SINGLE-FAMILY DISCONNECTED RAIN GARDEN LOCATIONS Rain Gardens Figure 12. The RHESSys hydrologic model (A) used to predict the effects of green infrastructure effects on hydrologic connectivity and stormwater runoff dynamics in the DR5 watershed (B) km Rooftop Connectivity 100% 75% 50% 25% 0% 0 Jan-00 Jan-02 Jan-04 Jan-06 Jan-08 Jan-10 Jan-12 Water table depth (mm) Water table depth (mm) Suburban (Gwynnbrook) Forested (Pond Branch) 2.4 Nitrate (mg N L -1 ) Urban (Cahill) Suburban Suburban Forested (Pond (Glyndon) (Gwynnbrook) Branch) Figure 4. Long-term water table depth and 5

6 Socio-Cultural-Economic Template Human Behavior Urban Tree Canopy Goals 4 Human Outcomes External Drivers 5 Knowledge of Impaired Management Strategy 4 Events Pulses Reduced Flooding, Increased Infiltration 1 Presses Urban Watershed Improvements Ecosystem Services Reduced Nitrate Retention Actual Geophysical and Infrastructural Template Community Structure 1 Riparian Disconnection 1 2 Ecosystem Function Nitrate loading 3 American Robin Northern Cardinal European Starling House Sparrow Figure 8. Kriged distributions of American Robin, Northern 6

7 Percent change in activity Percent change in activity Walk/jog Walk/Jog Bike/sports Drive Drive Swim Canoe/kayak/sailing Motorboat/fish Region City W263 Region City W263 Complex Heterogeneity Where are the trees, really? 7

8 The Cover Elements Gwynns Falls Patch Map Periodic Table of Baltimore Heterogeneity 8

9 Structural Classes Only MRLC 1999 Cadenasso et al. unpubl. Fine Scale Analysis IKONOS Image Vegetation Parcels PROW Vegetation Private Land Vegetation 9

10 10

11 % Existing Tree Canopy 0% - 18% 19% - 41% 42% - 64% 65% - 87% 88% - 100% % Possible Tree Canopy 0% - 16% 17% - 38% 39% - 58% 59% - 79% 80% - 100% 11

12 Who owns the trees? 10% COMMERCIAL 38% RESIDENTIAL 27% INSTITUTIONAL 22% RIGHTS-OF-WAY 3% AG RICULTURAL Who has the most room to plant new trees? ACRES THE NUMBER OF ACRES OF POSSIBLE TREECANOPY INSTITUTIONAL COMMERCIAL RESIDENTIAL RIG HTS-OF-WAY Heterogeneity as Cause and Consequence 12

13 Dynamic Heterogeneity Theory 13

14 Trees as a Source of Heterogeneity Life cycle processes: Dispersal, birth, health, death. Niche (habitat) differences Interaction with people Trees as Habitat Canopy Cover & Dead Wood % Trees with Large Dead Branches (>6in) % PA3-P Primary excavators Present Absent % Canopy 300m % Canopy Cover (300m radius) Logistic model: N=51, R 2 =0.3 0, p< , both variables signif icant ( p<0.0 1 ) PS Warren 14

15 Trees as Mediators Trees as Amenity 15

16 Trees as Disamenity Controls on Tree Heterogeneity Wealth Lifestyle Culture Legacy Conclusions Trees function in urban ecosystems Participation in cascades of heterogeneity Implications of the cascades (+/-) Beyond the big green patches 16