Considerations in Developing The Ohio State University Athletic Complex

Transcription

1 Considerations in Developing The Ohio State University Athletic Complex T. Davis Sydnor and Sakthi Subburayalu School of Environment and Natural Resources February 1, 2013

2 Considerations in Developing The Ohio State University Athletic Complex EXECUTIVE SUMMARY An update of the inventory of campus trees has been conducted by the Shade Tree Inventory Klub (STIK), a student group associated with the Chadwick Arboretum, and the School of Environment and Natural Resources since Included in the areas currently inventoried are the 568 trees identified as being in the area designated by the One Framework Plan as the area to be developed by the Athletic Department. Figure 1 shows the subject trees in pink, overlaid on a working drawing suggesting development areas subject to funding requirements and the changing needs of the department. The current working drawing was provided by Physical Planning and Real Estate for our use in developing this report. It is understood that the area will be developed and that some trees will be lost during development. This report will detail what is present, the annual environmental benefits being delivered, some of the costs involved in development and some suggestions as to how development can be done at reduced initial cost and with an eye toward reducing ongoing maintenance costs following construction. The analysis of environmental impacts was conducted by The Ohio State University s School of Environment and Natural Resources using itree, a software suite distributed by the USDA Forest Service. The specific program in the itree suite used to identify tree benefits was istreets. Landscape values were determined using Guide to Plant Appraisal of Trees and Other Plants in Ohio, seventh edition by Sydnor et al. Additional cost estimated were done using techniques developed during original research by Dr. Sydnor and Subburayalu. The existing tree population in the development area is diverse using commonly employed guidelines. A long standing rule of thumb for taxonomic biodiversity in the urban forest is the 10:20:30 guideline which suggests that no more than 10 percent of trees should be from the same species, no more than 20 percent should be from the same genera, and no more than 30 percent should be from the same family. Oak is present at 10 percent but is below a genus recommendation of 20%. All other species, family and genera are below the guidelines (Table 1). Retaining a diverse canopy is needed to guard against the loss of large numbers of a single species as evidenced by the recent loss of ash trees near the Bill Davis Stadium as a result or emerald ash borer (EAB). The existing tree population is skewed toward smaller trees. While 43% of the existing kinds of trees in the development area are considered larger growing species of trees and capable of getting larger than 24 inches in diameter only 12% are greater than 24in. (Table 2). Nearly 30% of the trees, many 50 years old, are less than 12in. According to Greg McPherson and others smaller trees may never generate positive returns environmental benefits to cover the original acquisition, planting and ongoing maintenance costs. Larger growing native trees suggestions, poorly represented now, include Kentucky coffeetree; Shumard, swamp white, and chinquapin oaks; American sycamore; buckeye; basswood; catalpa; and sweetgum. Introduced species can be used as well if desired and if their use is consistent with university guidelines. The dollar value of the annual environmental benefits delivered by the 568 existing trees is 63,712 or a n average of $112 per tree (Table 3). The largest benefit of existing trees is their ability to intercept rainfall and reduce storm water runoff ($21,483). Storm water runoff is a major cost for Columbus, OH. The Columbus campus is cooperating with Columbus on a multi-billion dollar sewer and storm water upgrade for the community. All of the development area storm water resulting from increased impervious surfaces will drain to the Olentangy River and will need to be addressed. 2

3 The next largest annual contribution is from aesthetic and other benefits ($21,312). The impact on campus is not so much from enhanced property value as campus is not for sale but on intangibles. Customer surveys suggest that customers prefer to spend their money and time in commercial streetscapes with trees and are willing to spend up to 11% more in such an environment. Might this affect the ability of development officers working to secure support for university programs such as athletics? The ability of athletic programs to recruit top flight student athletes would be positively influenced in a setting featuring greater maturity. This characteristic may be most critical for scholar athletes considering programs such as Duke, Notre Dame, Northwestern and yes, that school up north. Large trees promote the idea of stability and security. The third largest environmental benefit is for energy savings ($16,390). Natural gas and electricity are saved by shading structures, evaporating water (evapotranspiration) and reducing wind speed around structures. The direct savings are augmented by indirect savings as well by reducing the need for additional power plants. Annual air quality savings (reduced ozone, nitrous and sulfur oxides as well as particulate matter) for the trees save more than $2,000 while improving the air quality in the complex. Retaining larger trees, where possible, will be important for tomorrow s athletic complex. Carbon sequestration in this report comes in two forms including annual sequestration ($2,000) which is carbon sequestered in a single year (Table 3). The other form represents the carbon removed from the air and stored in the trees over time (Table 4). Over 2 million pounds (2,000 tons) carbon have been stored by the existing trees over time. When trees are removed the stored carbon is returned to the environment as the wood deteriorates. Since the university wishes to become carbon neutral by 2050, this carbon must be accounted for. Retaining larger trees helps. Removing and replacing trees cost money as well (Table 5). Just removing the existing trees will cost more than $300,000 while removing them with a replacement will cost more than $500,000. Note that removing a large tree may be 20 times as much. Again this argues for saving larger trees in preference to smaller ones. Existing trees have value. Nearly 1.2 million dollars are shown in this example (Table 6). Landscape values of existing trees are given by differing size categories. Species, condition and location values are averaged for the existing trees but will need to be considered when making a decision to save, plant, or remove a specific tree. One thing which pops out is the influence of size on the delivery of environmental benefits, landscape value, carbon storage, and even removal costs. Table 7 was developed to explore this aspect. One thing is for sure and that is that a tree will never deliver the benefits of a larger three if it is removed as a smaller tree. Often we hear that it is easier, even cheaper, to remove existing vegetation and replace it. This ignores annual environmental benefits. Table 7 assumes the growth rate of the 568 existing trees in the development area which have grown for 50 years and extrapolates that growth to 75 years. In the first 25 years those trees would have generated $172,534 in annual benefits. During years those trees generated $829,045 in benefits and are extrapolated to generate $3,983,629 in benefits during years Now let s say that the trees are removed and replaced, at the end of 25 years they would have produced $172,534 in benefits. Instead, if the trees had been retained they would have produced $3,983,629. Thus the removal and replacement of 50 year old trees by 2-inch trees would have cost the university nearly 4 million in lost environmental benefits during years ($3,983,629-$172,534) The oaks lining Lane Avenue at the Schottenstein Center were removed rather than move a service line. Those 8- inch oaks never paid the university back for planting and maintenance costs nor will they ever become twenty year old trees as they have been replaced with 2-inch trees. The difference in environmental benefits between recent transplants and trees established for 15 years will be felt for decades. We cannot and should not save every tree but we can evaluate trees for retention and enjoy the benefits of the environmental responsibility we profess to seek. 3

4 Figure 1. The study area from the Schottenstein Center north to Ackerman Road and west to State Route 315 is shown above. Pink dots represent the 568 trees that might be impacted by construction and the subject of this report. The building areas in black are higher priorities for development and grey footprints represent lower priority areas. 4

5 Table 1. Species Distribution of Common Trees in the OSU Athletic Development Area Arranged from the Most to Least Commonly Seen Species Percent Oak Austrian pine 8.98 Sugar maple 6.34 Honeylocust 5.46 Crabapple 5.46 Northern red oak 5.11 Norway spruce 4.23 Scotch pine 4.23 Red maple 3.52 Eastern white pine 3.52 OTHER SPECIES Total

6 Table 2. Relative Age (Size) Distribution of the 10 Most Common Trees in the Athletic Complex Development Area by Common Names Species Oak Austrian pine Sugar maple Honeylocust Crabapple Northern red oak Norway spruce Scotch pine Red maple Eastern white pine Existing Age Composition

7 Table 3 Total Annual Environmental Benefits of the Existing Trees in the Athletic Complex Development Area Benefits Total ($) $/tree Stormwater $21,483 $38 Aesthetic/Other $21,312 $38 Energy $16,390 $29 Air Quality $2,439 $4 CO2 $2,088 $4 Total Benefits $63,712 $112 7

8 Table 4. Carbon Stored over Time in Existing Trees in the Development Area Designated for the OSU Athletic Complex Species Total stored CO2 (lbs) Total ($) % Total Tree Numbers % of Total $ Avg. $/tree Silver maple $1, $ American sycamore $1, $ Littleleaf linden $1, $91.82 Green ash $ $51.47 Honeylocust $1, $50.63 London planetree $ $46.77 Sugar maple $1, $44.81 Apple $ $34.01 Northern red oak $ $26.31 Callery pear $ $24.33 Red maple $ $19.76 Oak $1, $19.68 English elm $ $17.32 Norway maple $ $16.95 Austrian pine $ $14.39 Arnolds crabapple $ $12.12 Norway spruce $ $10.32 Scotch pine $ $9.82 Hawthorn 8485 $ $9.09 Eastern white pine $ $6.64 Slippery elm 7422 $ $4.28 Western white pine $ $4.14 Blue spruce 1595 $ $1.20 White spruce 505 $ $0.42 OTHER STREET TREES $2, $25.40 COMPLEX TOTAL 2,143,308 $16, $

9 Table 5 Estimated Expenses for Removal and Replacement of Trees in the Area Slated for the Athletic Complex Development SIZE NUMBER REMOVAL COSTS PER TREE REMOVAL TOTALS REPLACEMENT COST/TREE (2-in) REPLACEMENT TOTALS REMOVAL AND REPLACEMENT $100 $2,800 $290 $8,120 $10, $375 $46,125 $290 $35,670 $81, $375 $51,000 $290 $39,440 $90, $675 $84,375 $290 $36,250 $120, $675 $58,725 $290 $25,230 $83, $1,290 $51,600 $290 $11,600 $63, $1,625 $32,500 $290 $5,800 $38, $2,150 $19,350 $290 $2,610 $21,960 >42 0 $2,150 $0 $290 $0 $0 TOTALS 568 $346,475 $164,720 $511,195 9

10 Table 6. Landscape Values of 568 Existing Trees in the Area Slated for Development into the Athletic Complex. SIZE NUMBER BASIC VALUE SPECIES VALUE CONDITION VALUE LOCATION VALUE LANDSCAPE VALUE EACH LANDSCAPE VALUE 1-3 (2) 28 $ $105 $2, (5) 123 $ $384 $47, (9) 136 $2, $1,111 $151, (15) 125 $4, $2,099 $262, (21) 87 $6, $3,364 $292, (27) 40 $9, $4,931 $197, (33) 20 $13, $6,810 $136, (39) 9 $17, $8,755 $78,797 >42 (45) 0 $20, $10,527 $0 TOTALS 568 $1,168,538 10

11 Table 7. Annual Environmental Benefits for Years 1-75 and Cumulative Benefits for Three, Selected Twenty-five Year Segments. YEAR ANNUAL BENEFITS YEAR ANNUAL BENEFITS YEAR ANNUAL BENEFITS 1 $2, $14, $67,841 2 $3, $15, $72,237 3 $3, $16, $76,918 4 $3, $17, $81,902 5 $3, $18, $87,209 6 $4, $19, $92,860 7 $4, $20, $98,878 8 $4, $21, $105,285 9 $4, $23, $112, $5, $24, $119, $5, $26, $127, $5, $28, $135, $6, $29, $144, $6, $31, $153, $7, $34, $163, $7, $36, $173, $8, $38, $185, $8, $41, $197, $9, $43, $210, $9, $46, $223, $10, $49, $238, $10, $52, $253, $11, $56, $270, $12, $59, $287, $13, $63, $306,142 YEARS 1-25 $172,534 YEARS $829,045 YEARS $3,983,629 11