City Trees is a premier publication focused on urban + community forestry. In each issue, you’ll learn how to best manage the trees in your community and more!
Issue link: http://read.dmtmag.com/i/443459
ÌÞÊ/Àiià "ACKGROUND 4HE -ILLION4REES.9# INITIATIVE WAS CATALYZED BY RESEARCH THAT SHOWS ON AVERAGE .EW 9ORK #ITY STREET TREES CUR RENTLY RETURN TO THE COMMUNITY FOR EVERY SPENT ON MANAGEMENT )N THE COURSE OF FULFILLING THE MISSION OF -ILLION4REES.9# .9# 0ARKS $EPARTMENT FORESTERS ARE TASKED WITH DESIGNING PLANTING SPACES AND SELECTING TREE SPECIES FOR EACH SITE THEN OVERSEEING CONSTRUCTION AND COMMUNITY ENGAGEMENT 4WO FACTORS THAT AFFECT PLANT SELECTION IN .9# TO GUARAN TEE BIODIVERSITY WE USE OVER DIFFERENT TREE SPECIES CULTIVARS AND SELECTIONS GROWN UNDER CONTRACT BY TREE NURSERIES IN THE REGION 3ECOND THE PLANTING SITES THAT WE SURVEY HAVE VARYING ENVIRONMENTAL CONSTRAINTS 3ELECTION CAN BE A SIMPLE TASK ON A TREEBYTREE BASIS BUT THIS IS NOT EFFICIENT WHEN IT COMES TO MAKING THOU SANDS OF SELECTIONS PER SEASON 7E NEEDED A DECISION MAKING PROTOCOL TO ENSURE CONSISTENCY AND ACCURACY THROUGHOUT THE URBAN FORESTRY PROGRAM WHILE CONSIDER ING THE REALITY OF OUR FORESTERS TIME CONSTRAINTS 7E ALSO WANTED TO OPTIMIZE THE NET BENEFITS OF OUR TREE PLANTINGS BY SYSTEMATICALLY MAXIMIZING EACH PLANTING SITES POTENTIAL $EVELOPING A #LASSIFICATION 3YSTEM FOR 3TREET 4REE 0LANTING 3ITES /UR FIRST TASK WAS TO DEVELOP A CLASSIFICATION SYSTEM TO DISTINGUISH THE DIFFERENT STREET TREE PLANTING CONDITIONS WE COME ACROSS %ACH SITE IS ITS OWN HABITAT OR BIOTOPE A SUBSECTION OF A BIOME FOR A TREE 7E AIMED TO DEFINE THE VARIOUS ENVIRONMENTAL CONDITIONS THAT WOULD SET ONE STREET TREE BIOTOPE APART FROM ANOTHER 4HIS WAS A DIFFICULT TASK GIVEN THE DIVERSE LANDSCAPES OF .EW 9ORK #ITY 7E HAD TO CHOOSE THE MOST SIGNIFI CANT CRITERIA INFLUENCING A FORESTERS SELECTION DECISION )F WE SPLIT HAIRS WE COULD HAVE HUNDREDS OF DIFFERENT BIOTOPES BUT SUCH A SPECIFIC CLASSIFICATION SYSTEM WOULDNT BE VERY HELPFUL TO ANYONE IN THE FIELD "UT BY FRAMING THE BIOTOPES A LITTLE MORE BROADLY THEY WOULD BE MORE EASILY IDENTIFIED IN THE FIELD (OW DID WE DETERMINE THE MOST SIGNIFICANT AND COM MON CRITERIA IMPACTING TREE SELECTION -ANY CONDITIONS ARE ALREADY HELD CONSTANT ACROSS THE #ITY FOR VARIOUS REASONSFOR EXAMPLE BECAUSE OF CONTRACT SPECIFICA TIONS &OR INSTANCE SOIL COMPOSITION WITHIN THE TREE BED IS UNIFORM BECAUSE EACH EXCAVATION IS BACKFILLED WITH A SPECIFIED TOPSOIL 4HERE ARE ALSO SOME CONDITIONS THAT VARY HOWEVER UNCOMMONLY &OR INSTANCE THE MAJORITY OF PLANTING SITES WILL HAVE A FULLSUN CONDITION BECAUSE STREETS ARE TYPICALLY WIDE RELATIVE TO BUILDING HEIGHT BUT SOME SITES WILL BE OUTLIERS WITH A PARTIALSUN CONDITION !DDITIONAL MAJOR FACTORS TO CONSIDER THERE IS A DRAMATIC RANGE OF HOW hURBANv A PLANTING SITE CAN BE ACROSS THE #ITYPARTS OF -ANHATTAN RESEMBLE A CONCRETE JUNGLE WHILE PARTS OF THE OUTER BOROUGHS CONSIST OF SINGLE FAM ILY HOMES WITH LUSH LAWNS AND QUIET STREETS !NOTHER BIG FACTOR IS WHETHER OR NOT A PLANTING SITE HAS OVERHEAD POWER LINES IF SUCH WIRES ARE PRESENT ONLY A SMALL ORNAMENTAL TREE SPECIES WOULD BE CHOSEN -OST NEIGH BORHOODS THROUGHOUT THE OUTER BOROUGHS HAVE ELECTRIC POWER LINES OVER ONE SIDE OF THE STREET ! THIRD MAJOR FACTOR IS THE TOTAL SOIL VOLUME AVAILABLE TO THE TREE 4YPICALLY TREES ARE HEADED FOR CUTOUTS THAT HAVE BEEN SHAPED AND SIZED TO ACCOMMODATE BOTH THE TREE AND PEDESTRIAN TRAFFIC ON THE SIDEWALK 4HESE CUTOUTS VARY IN SIZE DUE TO THE FLUCTUATING SHAPE AND SIZE OF THE PUBLIC RIGHTOFWAY THROUGHOUT THE #ITY OR TO UNDERGROUND UTILITIES OR TO OTHER SAFETY AND SPACING GUIDELINES THAT ARE USED THROUGHOUT THE #ITY )N SOME NEIGHBORHOODS OF THE OUTER BOROUGHS TREES ARE PLANTED IN EXTENDED LAWN STRIPS INSTEAD OF IN CONCRETE CUTOUTS 4HIS ALLOWS FOR EXTRA ROOT ING VOLUME AS WELL AS OTHER SITE CONDITION BENEFITS $EFINITION OF #RITERIA 4HE FOLLOWING IS AN OVERVIEW OF HOW WE DEFINED THESE THREE MAJOR CRITERIA USED TO CLASSIFY OUR BIOTOPES 3ITE #ONDITION ! FORESTER JUDGES A SITES DEGREE OF DROUGHT CONDITION SOIL COMPACTION AND SOIL POLLUTION THEN PROVIDES A SITE CONDITION RATING ! .EW -ETHOD FOR 3TREAMLINING 4REE 3ELECTION IN .EW 9ORK #ITY CZ%BWJE.PPSF'PSFTUFS/FX:PSL$JUZ1BSLT%FQBSUNFOU %BWJE.PPSF!QBSLTOZDHPW 4HE PURPOSE OF THIS ARTICLE IS TO SHARE HOW THE .EW 9ORK #ITY 0ARKS $EPARTMENT STREAMLINED OUR SYSTEM FOR MAKING TREE SPECIES SELECTIONS FOR STREET TREE PLANT INGS A YEAR 7E HOPE THAT OUR SYSTEM PROVIDES USEFUL INSIGHTS THAT CAN BE ADAPTED AND CUSTOMIZED TO THE NEEDS OF OTHER CITIES UNDERTAKING STREET TREE PLANTING