The Influence of New York City Urban Soils on Native Tree Seedling Growth and Survival

Transcription

1 The Influence of New York City Urban Soils on Native Tree Seedling Growth and Survival Clara Pregitzer Natural Resources Group New York City Department of Parks and Recreation

2 Planting Trees in New York City Soil Urban soils have a reputation of being widely variable. Management history knowledge varies on a site by site basis and land use maps are often not representative of local site conditions. Urban soils often are subject to greater disturbance, an invasive seedbank and earthworms. Top: Holes ready to be planted with container trees. Bottom: Degraded urban landscape.

3 Land use history in New York City is complex and parkland available for forest restoration is often degraded or compromised Land use history legacies are complex in urban parkland and hard to keep track of.

4 Forest Restoration in New York City New York City has 29,000 acres of parkland. 10,000 acres of Natural reas including 5,300 acres of Forest. Natural Resources Group has been managing and restoring parkland in New York City for 30 years. Under a new sustainability initiative MillionTreesNYC has resulted in 339,814 native trees planted in natural areas across NYC in the past 5 years. Top: Forest restoration sign at Conference House Park, Staten Island. Bottom: Volunteers planting trees in Queens.

5 Variation in survival of planted tree seedlings exists across New York City Parks Top: Forest restoration sign at Conference House Park, Staten Island. Bottom: Volunteers planting trees in Queens. Simmons, B. (n.d.). MillionTreesNYC: Reforestation survival study. Unpublished raw data, NYC Urban Field Station, New York, NY.

6 Project Goal: To better understand urban soils and the traits important to native tree growth New York City s soils have been subject to a wide range of physical disturbances including burial or coverage of natural soil by fill material of varying quality. To maximize success reforestation efforts in New York City understanding the complexities of urban soils is key. How do urban soils with different land use histories influence native tree growth and survival? Top: pre-dug holes for planting container trees. Bottom: Forest Restoration Site, Van Cortlandt Park. 6

7 Project Design Using 12 urban field soils collected from different NYC Parks we planted 4 native tree species in replication into each of the 12 urban field soils creating a common garden greenhouse experiment. greenhouse soil mix was added as a control. Tree mortality, caliper, height, leaf discoloration and chlorophyll fluorescence were measured. We tested the soil characteristics in the lab to compare trends in tree mortality and health to the traits of urban soils. Top: Trees growing in urban soils in the greenhouse. Bottom: Measuring caliper growth. 7

8 Field soils were collected from 4 categories of New York City urban soil CUSTOM FILL URBN FILL COL SH NTIVE TILL 8

9 Custom Fill Considered clean fill Contractually specified particle size and chemistry Soil that is placed over a degraded urban soil Originates from excavation projects and recycled at forest restoration sites Often very sandy and usually lower nutrient content 9

10 Urban Fill Native soil mixed with waste such as construction or demolition debris or household trash from regulated or unregulated dumping. Highly variable Characteristic of urban lots, where the dominant vegetation is typically invasive Often have a high ph (7-9) NYC Parks own over 1,000 acres of filled land 10

11 Coal sh During the 19 th and early 20 th Century New York City coal ash from heating homes was dumped into regulated and unregulated locations which later became NYC parks Very fine in particulate matter and thought to be high in micronutrients 11

12 Native Glacial Till In the northeast of the US, forest soils are typically welldrained sandy loams or loams Relatively low available nitrogen ph levels ranging neutral to slightly acidic ( ) Pockets of mature native forest exist in New York City parks and are dominated by native trees, shrubs and understory 12

13 Title of Presentation Goes Here 13

14 Collecting Field Soil Field soil was collected from the top inches within each site and homogenized in a 30 gallon trash can and brought back to the greenhouse

15 Project Design Four native tree species Silver maple (cer Saccharinum), Black birch (Betula lenta), Red oak (Quercus rubra) and Canadian serviceberry (melanchier canadensis) were planted into each soil. 9 replicates of each species were transplanted into one gallon buckets containing a field soils. Total of 13 soils were used (n=468) Top: Seeds were collected and grown in plugs before being transplanted into urban soils. Bottom: Project design in the greenhouse.

16 Data Collection t the establishment of the project and then at the end of the growing season (July-October) height, caliper and mortality and chlorophyll fluorescence was measured. sub-sample of each field soil was sent to the Brooklyn College soil lab to be tested for ph, macro and micro nutrients, texture, CEC, TOC and heavy metals. Top: Measuring height of each tree. Bottom:Collecting data in the greenhouse.

17 Chlorophyll fluorescence as a metric for plant stress Chlorophyll fluorescence was measured on each tree. By measuring the intensity and nature of this fluorescence we are collecting a metric for plant stress.

18 Soil Results Soil Location Soil Type ph Salt (ppm) TOC (%) CEC % Sand Mg l P K Ca Mn Coal sh Coal sh Coal sh Urban Fill Marine Park Urban Fill Urban Fill Marine Park Custom Fill Custom Fill Custom Fill lley Pond Native Till Cunningham Native Till Native Till Control

19 Soil Results Soil Location Soil Type ph Salt (ppm) TOC (%) CEC % Sand Mg l P K Ca Mn Coal sh Coal sh Coal sh Urban Fill Marine Park Urban Fill Urban Fill Marine Park Custom Fill Custom Fill Custom Fill lley Pond Native Till Cunningham Native Till Native Till Control

20 Soil Results Soil Location Soil Type ph Salt (ppm) TOC (%) CEC % Sand Mg l P K Ca Mn Coal sh Coal sh Coal sh Urban Fill Marine Park Urban Fill Urban Fill Marine Park Custom Fill Custom Fill Custom Fill lley Pond Native Till Cunningham Native Till Native Till Control

21 Soil Results Soil Location Soil Type ph Salt (ppm) TOC (%) CEC % Sand Mg l P K Ca Mn Coal sh Coal sh Coal sh Urban Fill Marine Park Urban Fill Urban Fill Marine Park Custom Fill Custom Fill Custom Fill lley Pond Native Till Cunningham Native Till Native Till Control

22 Soil Results Soil Location Soil Type ph Salt (ppm) TOC (%) CEC % Sand Mg l P K Ca Mn Coal sh Coal sh Coal sh Urban Fill Marine Park Urban Fill Urban Fill Marine Park Custom Fill Custom Fill Custom Fill lley Pond Native Till Cunningham Native Till Native Till Control

23 Survivorship Results Soil % Survival Site Category Black Birch Serviceberry Silver Maple Red Oak Coal sh 100% 100% 100% 100% Coal sh 100% 100% 100% 100% Coal sh 100% 100% 100% 100% Urban Fill 66% 88% 100% 44% Marine Park Urban Fill 100% 88% 100% 100% Urban Fill 100% 100% 100% 100% Marine Park Custom Fill 100% 100% 100% 88% Custom Fill 77% 100% 100% 100% Custom Fill 100% 100% 100% 100% lley Pond Native Till 100% 100% 100% 100% Cunningham Native Till 100% 100% 100% 100% Native Till 100% 100% 100% 100% GNCP Control 100% 100% 100% 100% 23

24 Survivorship Results Soil % Survival Site Category Black Birch Serviceberry Silver Maple Red Oak Coal sh 100% 100% 100% 100% Coal sh 100% 100% 100% 100% Coal sh 100% 100% 100% 100% Urban Fill 66% 88% 100% 44% Marine Park Urban Fill 100% 88% 100% 100% Urban Fill 100% 100% 100% 100% Marine Park Custom Fill 100% 100% 100% 88% Custom Fill 77% 100% 100% 100% Custom Fill 100% 100% 100% 100% lley Pond Native Till 100% 100% 100% 100% Cunningham Native Till 100% 100% 100% 100% Native Till 100% 100% 100% 100% GNCP Control 100% 100% 100% 100% 24

25 Results: Growth (averaged for all species) 12 Coal sh Custom Fill p<01 verage Growth cm (height) Urban Fill Native Till Greenhouse mix Soil Origin lley Pond Cunningham Greenhouse Data from July-October 2012 growth period

26 Species Growth Patterns 14 verage growth (height) p< Height 8 6 B 4 C 2 C 0 Black Birch Red Oak Serviceberry Silver Maple Tree Species Top: measuring trees in the greenhouse Bottom: view from below.

27 Plant Stress (z-score) Black birch D D DEF EF Red oak D D Urban Fill Urban Fill Custom Fill Custom Coal shfill Coal Native sh Till Native Till - Silver maple lley Pond Cunnigham Park F F Cunnigham Park Serviceberry DE DE lley Pond Park E Plant Stress (z-score) B B D lley Pond D D DE Cunnigham E lley Pond Cunnigham C

28 Plant Stress (z-score) Black birch D D DEF EF Red oak D D Urban Fill Urban Fill Custom Fill Custom Coal shfill Coal Native sh Till Native Till - Silver maple lley Pond Cunnigham Park F F Cunnigham Park Serviceberry DE DE lley Pond Park E Plant Stress (z-score) B B D lley Pond D D DE Cunnigham E lley Pond Cunnigham C

29 Plant Stress (z-score) Black birch D D DEF EF Red oak D D Urban Fill Urban Fill Custom Fill Custom Coal shfill Coal Native sh Till Native Till - Silver maple lley Pond Cunnigham Park F F Cunnigham Park Serviceberry DE DE lley Pond Park E Plant Stress (z-score) B B D lley Pond D D DE Cunnigham E lley Pond Cunnigham C

30 Plant Stress (z-score) Black birch D D DEF EF Red oak D D Urban Fill Urban Fill Custom Fill Custom Coal shfill Coal Native sh Till Native Till - Silver maple lley Pond Cunnigham Park F F Cunnigham Park Serviceberry DE DE lley Pond Park E Plant Stress (z-score) B B D lley Pond D D DE Cunnigham E lley Pond Cunnigham C

31 Plant Stress (z-score) Black birch D D DEF EF Red oak Urban Fill Urban Fill Custom Fill Custom Coal sh Fill Coal Native sh Till Native Till D D - Silver maple lley Pond Cunnigham Park F F Cunnigham Park Serviceberry DE DE lley Pond Park E Plant Stress (z-score) B B D lley Pond D D DE Cunnigham E lley Pond Cunnigham C

32 Trends Native soils and coal ash soils are best However urban fill is not always bad for all species Custom fill can be low in organic matter and need additional inputs Tree growth is correlated with lower soil ph and higher %TOC verage Increase in Height ph r2=9 p=022 Top: Trees grow taller in lower ph. Bottom: Trees in the greenhouse.

33 Conclusions/ Implications Don t generalize land use history with the growth potential of urban soils Overall tree mortality was low, but in the greenhouse Species interact with the range of urban soil environments differently Urban soils are still complex but nonetheless hold opportunity for native plant restoration Top: Trees in the greenhouse Bottom: Reforestation site in Bronx, NY. 34

34 Next steps Let the trees grow another season bove-below ground biomass Leaf and root foliar sampling for micronutrients Resample soil from pots and see if nutrients and heavy metals can be traced to the leaves or roots. Potential for more common garden experiments to be incorporated in forest restoration efforts Top: Trees in the greenhouse ugust, 2012 Bottom: Trees in the greenhouse February,

35 Thank you! Collaborators: Nancy Falxa-Raymond, Rich Hallett, Tim Wenskus Support and field assistance: Leila Mougoui-Bakhtiari, Jeremy Lessing, Tim Wenskus, Jennifer Greenfeld, Camille Joseph, Ed Toth, Tim Chambers, Jackie Lu, Ellen Pehek, Brady Simmons, Joshua Cheng, Chisato Shimada, Mike Feller, Kat Bounds, Kathleen McCarthy, dam Thornbrough