Inventory and Assessment of Shelburne Farms Woodlots

Transcription

1 Inventory and Assessment of Shelburne Farms Woodlots FOR 195 Natural Resource Ecology and Assessment II Rubenstein School of Environment and Natural Resources University of Vermont April 27, 2016

2 INTRODUCTION During the spring of 2016 a group of UVM Forestry, Wildlife, and Natural Resource Ecology students measured the Shelburne Farms woodlots in Shelburne, VT as part of FOR 195: Natural Resource Ecology and Assessment II. The goal of the project was to set up a long-term measurement plan so that Shelburne Farms can monitor their woodlots. Currently, Shelburne Farms utilizes their woodlot for maple syrup and sawlogs production. They would also like to manage the forest to produce veneer quality sugar maple logs. Although they favor sugar maple trees at Shelburne Farms, diversity is also important to them. They would like to maintain a diverse forest while at the same time increasing syrup production and veneer production. Another concern of the landowners is the regeneration in some of their sugar maple stands, as there are very low levels of regeneration in some of those stands. They would like to actively manage these stands to increase the regeneration levels. Another goal of the management is to increase the number of taps that they have in their sugaring operation. They have plenty of room to expand their operation without acquiring more land. METHODS In order to gather inventory data at Shelburne Farms, the class used the existing stand delineations used in the Shelburne Farms woodlot management plan and focused on those areas with the greatest amount of forest cover. An initial survey of forest conditions was done to assess the level of variability in each stand and determine appropriate sample size. Based on this, two to four, two fixedradius 1/5th acre plots were randomly located within each stand (Figure 1). Within each 1/5th acre plot all overstory trees and snags greater than 4 in diameter were recorded. A nested 1/50th acre plot was created at Figure 1: Plot layout for inventory. the center of each overstory plot in order to tally saplings (trees greater than 4.5 in height and less than 4 in diameter). Three

3 transects were laid out from the plot center at azimuths of 30, 150, and 270. Along each transect each piece of downed woody debris that exceeded 3 in diameter and crossed each transect was measured. Additionally, 26 from plot center along each transect, a 1/1000th acre plot was established to tally all woody stems less than 4.5 in height. The following pages contain two-page summaries of the forest conditions for each of the sampled stands and associated management recommendations. 3

4 Stand Structure in Shelburne Farms: Stand 2 Matt Marshall, Matt Hamor, Nick Hayward, Hayden Coakley Key Findings in Stand 2: Low density stand but moderately stocked, indicative of recent thinning Hardwood dominated (Sugar Maple) Strong presence of understory sugar maple Medium density of invasive buckthorn Ironwood in mid-canopy Management Recommendations: Due to high site quality, timber production and focus on promoting stand health would be better options than sugaring in this area. Remove overstory red oak for timber and to provide better growing conditions for sugar maple. Cut sugar maple above 16 inch DBH size class for timber to allow better growing conditions of young sugar maple for timber and/or tapping. Remove understory American beech and common buckthorn to reduce competition for young sugar maples. Promote growth of understory sugar maple by managing the stand according to the previous suggestions. Plant desired timber species (i.e. douglas fir) Remove ironwood (can be used as firewood) 30 Trees per acre WA RO IW SM Diameter Class (in) Figure 1: Diameter distribution of overstory trees in Stand 2. 4

5 Table 1: Attributes of downed woody debris (DWD) and snags in Stand 2 at Shelburne Farms. DWD Snags Volume (ft 3 /ac) Biomass (t/ac) Volume (ft 3 /ac) Biomass (t/ac) DBH (in) Density (#/ac) Table 2: Seedlings and saplings in Stand 2 at Shelburne Farms. Species Seedlings (#/acre) Saplings (#/acre) Sugar maple Common buckthorn American beech 0 50 Table 3: Richness, diversity, and evenness of the overstory and regeneration layer in Stand 2 at Shelburne Farms Layer Richness Diversity (H ) Evenness Overstory Regeneration Total biomass of stand 2 = 92.1 tons/acre Table 4: Tree overstory density, basal area, importance value, and DBH analyses of Stand 2 species Species TPA BA (ft/ac) IV DBH Sugar maple Red oak Ironwood White ash Total

6 Stand Structure in Shelburne Farms: Stand 4 Matt Marshall, Matt Hamor, Nick Hayward, Hayden Coakley Key Findings in Stand 4: Sugar maple dominated this stand Sugar maple present are in smaller diameter class (< ), most likely due to planting Large red oaks and white ash present Multiple invasives present (honeysuckle and buckthorn) Management Recommendations: Expand sugaring to this area as it is heavily dominated by small to medium sized sugar maple. These sugar maple are in a smaller size class suggesting that they are young trees and still have a long lifespan ahead of them. Removal of understory white ash, common buckthorn, honeysuckle, and rubus spp. To help promote growth of present sugar maple and increase accessibility of the site. 20 Trees per acre WA RO Butternut SM Diameter Class (in) Figure 1. Diameter distribution of overstory trees in stand 4. Table 1. Attributes of downed woody debris (DWD) and snags in Stand 4 at Shelburne Farms. DWD Snags Volume (ft 3 /ac) Biomass (t/ac) Volume (ft 3 /ac) Biomass (t/ac) DBH (in) Density (#/ac)

7 Table 2. Seedlings and saplings in stand 4 at Shelburne farms. Species Saplings (#/ac) Seedlings (#/ac) Sugar Maple White Ash Common Buckthorn Honeysuckle RUBUS Table 3: Richness, diversity, and evenness of the overstory and regeneration layer in Stand 4 at Shelburne Farms. Layer Richness Diversity (H ) Evenness Overstory Regeneration Table 4: Tree overstory density, basal area, importance value, and DBH analyses of Stand 4 species Species TPA BA IV DBH Sugar maple Red Oak White Ash Butternut Total Total biomass of stand 4 = 85.5 tons/acre 7

8 Stand Structure in Shelburne Farms: Stand 5 Lila Satterfield, Gabby Siebenaler, Lauren Newman,Grace Ullman, Sophie Granberry Stand 5 Key Findings: Stand was recently harvested Stand over story contains only one species, sugar maple. The regeneration in this stand contains three species, red maple, sugar maple and ash, and may increase the overall diversity of the over story in the future. Though not necessarily represented in the data, Stand 5 had a decent amount of snags and downed woody debris that was not captured by out plots. Stand 5 Management Recommendations: Stand 5 could be a possible sugar bush because of the abundance of mature sugar maples. If not interested in increasing sugaring in this area, could possibly manage for wildlife in the future because there is more tree diversity in the regeneration layer and the existing habitats such as downed woody debris and snags. Stand 5 Inventory Summary Table 1. -STAND 5 overstory tree conditions, including trees per acre (TPA), basal area (BA), importance value (IV), and diameter at breast height (DBH). Species TPA BA (ft 2 /ac) IV DBH (in.) Sugar maple Total Figure 1. Diameter Distribution Stand 5 Stand 5 Trees Per Acre DBH (inches) SM Figure 1: SM=Sugar maple 8

9 Stand 5 plots did not contain any snags. Table 2. Downed Woody Debris Volume and Biomass Stand 5 Stand Volume (ft 3 /ac) Biomass (t/ac) Table 3. Live Tree Biomass Stand 5 Stand Biomass (tons/acre) tons/acre Table 4. Sapling and Seedling Density in Stand 5 Species Seedlings (#/ac) Saplings (#/ac) Red Maple Sugar Maple Ash Table 5. Stand 5 Diversity and Richness Layer Richness Diversity (H ) Evenness Overstory Regeneration Image of Stand 5: Large sugar maples, with lots of regeneration 9

10 Stand Structure in Shelburne Farms: Stand 6 Jack Vallee, Adam Hart, Harry Voelkel, Isaac Estey Key Findings Sugar maple is the dominant overstory species within this stand, with American beech the second most dominant. The live tree biomass of stand 6 was 62 tons/acre. In the understory choke cherry had the most seedlings, and ironwood had the most saplings. Management Recommendations Manage the stand to increase Sugar Maple regeneration without taking away current productive Sugar Maple Trees. Control beech regeneration and favor sugar maple saplings. Table 1. Trees per acre, Basal area, Importance value, Diameter at breast height Species TPA BA (ft²/acre) IV (%) DBH (inches) American beech Bitternut hickory Black birch Ironwood Red maple Red oak Striped maple Sugar maple White ash White pine Total

11 Figure 1. Stand 6 diameter distribution of stems >4in diameter. Other hardwoods include red maple, red oak, black birch, and bitternut hickory. Table 2. Attributes of downed woody debris and snags in stand 6 in Shelburne farms The live tree biomass for stand 6 was 62 tons/acre. Seedling and Sapling Density Table 4. Seedlings and saplings in Stand 6 at Shelburne Farms. Species Seedlings (#/ac) Saplings (#/ac) Choke cherry Ironwood Sugar maple - 25 Striped maple White ash Table 5. Richness, diversity, and evenness of the overstory and regeneration layer in Stand 6 at Shelburne Farms

12 Stand Structure in Shelburne Farms: Stand 7 Jack Vallee, Adam Hart, Harry Voelkel, Isaac Estey Key Findings Sugar maple is the dominant overstory species within this stand, with white ash the second most dominant. The invasive species buckthorn is present in the stand There is a decent amount of sapling and seedling regeneration of both American beech and sugar maple in the stand. Management Recommendations Target hotspots of sugar maple regeneration with single tree selection. Target heavily diseased beech for removal to improve quality of the beech present. Treat buckthorn with herbicide application before opening up canopy. Figure 1. Trees per acre, Basal area, Importance value, Diameter at breast height Species TPA BA (ft²/acre) IV (%) DBH (inches) American beech Bitternut hickory Black birch Red oak Shagbark hickory Sugar maple White ash White birch Total

13 Figure 2. Stand 7 diameter distribution of stems >4in diameter. Other hardwoods include red oak, white birch, white ash, shagbark hickory, bitternut hickory, and black birch. Table 2. Attributes of downed woody debris and snags in stand 7 in Shelburne farms The live tree biomass for Stand 7 was 79.9 tons/acre. Seedling and Sapling Density Table 4. Seedlings and saplings in Stand 7 at Shelburne Farms Species Seedlings (#/ac) Saplings (#/ac) American beech Black birch Buckthorn Sugar maple White ash Table 5. Richness, diversity, and evenness of the overstory and regeneration layer in Stand 7 at Shelburne Farms. 13

14 Stand Structure in Shelburne Farms: Stand 8 Lila Satterfield, Gabby Siebenaler, Lauren Newman,Grace Ullman, Sophie Granberry Stand 8 Key Findings: Some topographic diversity within the stand which leads to microclimates that gives rise to different pockets of species in the stand. The stand is still not extremely diverse with only three tree species, American Beech, Red Oak and Sugar Maple. Noticed signs of self thinning which suggests the stand could be overpopulated Observed that there is lots of leaf litter, but did not measure the exact amount. Stand 8 Management Recommendations: Might think about thinning over story with a regeneration harvest to decrease the amount co-dominant and dominant trees in order to promote regeneration in the under story Could be a timber harvest for Stand 8 to increase revenue Decrease the amount of leaf litter to help promote regeneration Stand 8 Inventory Summary: Table 1. -STAND 8 Species TPA BA (ft 2 ) IV DBH (in.) American Beech Red Oak Sugar Maple Total Figure 1. Diameter Distribution Stand Stand 8 Trees Per Acre DBH Class (Inches) SM AB RO Figure 1: SM=Sugar maple, AB=American beech, RO=Red oak 14

15 Table 2. Stand 8 Snag Calculations Stand Volume (ft 3 /ac) Biomass (t/ac) DBH (in) Density (#/ac) ft 3 /ac 0.08 t/ac 6.0 in. 7.0 snags/ac Table 3. Stand 8 Downed Woody Debris Volume and Biomass Stand Volume (ft 3 /ac) Biomass (t/ac) ft 3 /ac 8.4 t/ac Table 4. Stand 8 Live Tree Biomass Stand Biomass (tons/acre) tons/acre Table 5. Stand 8 Sapling and Seedling Density Species Seedlings (#/ac) Saplings (#/ac) American Beech Sugar Maple Table 6. Stand 8 Richness and Diversity. Layer Richness Diversity (H ) Evenness Overstory Regeneration Image of Stand 8: very dense overstory conditions. 15

16 Stand Structure in Shelburne Farms: Stand 13 Süki Wilder, Anna Clayton, Jill Humphreys, Jonah Salzman-Cohen Key Findings: Has a number of larger mature (17-37 dbh class) sugar maple trees, potentially worth tapping [Fig 1] Dominant sugar maple presence across the board (regeneration, smaller trees, larger trees) American beech appears to be sugar maple s strongest competitor among lower diameter trees, but sugar maple appear to be winning out overall [Table 1] In saplings, ironwood (12.5 saplings/ac) more significant competitor against sugar maple (17.5 saplings/ac) than beech (3.75 saplings/acre) [Table 2] In seedlings, sugar maple overwhelmingly dominant, indicating promising sugar maple stand development [Table 2] Large amount of DWD and snags, promising for wildlife diversity and continued presence Highest biomass and diversity of natural stands sampled [Table 4] Management Recommendations: Prime stand for sugar bush expansion, both current mature trees and regen for the future Remove ironwood saplings to favor sugar maple regen Consider some beech thinning to favor low dbh sugar maple, but that would be at the risk of inadvertently encouraging beech regen Table 1 Density, basal area, importance value (IV), and average diameter at breast height (DBH) by species for Stand 13 at Shelburne Farms. TPA BA IV DBH American beech American elm bitternut hickory black birch ironwood sugar maple white ash Total Table 2: Seedlings and saplings per acre in Stand 13, Shelburne Farms Seedlings (#/ac) Saplings (#/ac) American beech black birch ironwood sugar maple white ash 5-16

17 Table 3: Attributes of downed woody debris (DWD) and snags in Stand 13 at DWD Snags Volume (ft 3 /ac) Biomass (t/ac) DBH (in) Density (#/ac) Table 4: Richness, diversity, and evenness of the overstory in Stand 13 of Shelburne Farms Overstory Regeneration Richness 7 5 Divesity (H') Evenness Live Biomass: tons/acre 40 trees/acre American beech other sugar maple dbh class (inches) Figure 1: Overstory diameter distribution by species in Stand 13, Shelburne Farms. American elm, black birch, bitternut hickory, ironwood, and white ash comprise the other category. 17

18 Stand Structure in Shelburne Farms: Stand 15 Süki Wilder, Anna Clayton, Jill Humphreys, Jonah Salzman-Cohen Key Findings: Much of this stand is overrun by invasive species such as buckthorn and a variety of other, non-native understory plants This stand is partially wetland, favoring some riparian species less common in other stands (e.g. black ash) Intense understory vegetation makes stand very difficult to traverse Highest biomass and diversity of all stands sampled [Table 8] Good number of snags (12.5/acre) for wildlife habitat [Table 6] Management Recommendations: As buckthorn dominates the stand s seedlings count, serious invasive removal is needed to propagate any sort of desired species in the future [Table 7] Due to its high diversity, perhaps best left as a biodiversity/wildlife zone than a future sugar bush Table 5: Density, basal area, importance value (IV), and average diameter at breast height (DBH) by species for Stand 15 at Shelburne Farms. TPA BA IV DBH basswood black ash buckthorn cottonwood eastern white pine northern white ceder Norway maple red maple red spruce sugar maple white ash Total Table 6: Attributes of downed woody debris (DWD) and snags in Stand 15 at Shelburne Farms. DWD Snags Volume (ft 3 /ac) Biomass (t/ac) DBH (in) Density (#/ac)

19 Table 7: Seedlings and saplings in Stand 15 at Shelburne Farms. Seedlings (#/ac) Saplings (#/ac) white ash - 25 buckthorn Table 8: Richness, diversity, and evenness of the overstory and regeneration layers in Stand 15 at Shelburne Farms. Overstory Regeneration Richness 11 2 Divesity (H') Evenness Live Biomass: tons/acre eastern white pine black ash 30 other red maple trees per acre red spruce white ash sugar maple northern white ceder dbh class (inches) Figure 2: Overstory diameter distribution by species in Stand 13, Shelburne Farms. Basswood, buckthorn, eastern cottonwood, and Norway maple comprise the other category. 19

20 Stand Structure in Shelburne Farms: Stand 16 Carlina Arango, Elizabeth Bannar, Diana Gurvich, Jamie Waterman Main Findings: Stand 16 exhibits high diversity and evenness in overstory trees Bitternut hickory had fairly high importance and made up the most basal area, sugar maple regeneration was widely present Management Recommendations: Stand 16 has relatively high species diversity so there is potential for management to maintain this diversity. Possible treatments include crop tree release for desired species such as black birch, black cherry, and shagbark hickory Successional trend is towards sugar maple, so treatments to encourage this regeneration are recommended Table 1: Overstory tree values per acre, basal area per acre, Importance Values, and average diameter at breast height in Stand 16, Shelburne Farms, VT. Species TPA BA (ft 2 /ac) IV DBH(in) American elm Black birch Black cherry Bitternut hickory Bigtooth aspen Ironwood Norway maple Shagbark hickory Sugar maple White ash White pine Total Table 2: Seedlings and sapling densities for Stand 16, Shelburne Farms, VT. Italicized species are non-native invasives. Species Seedlings (#/ac) Saplings (#/ac) Sugar maple Glossy buckthorn Common buckthorn 17 0 Bitternut hickory 66 0 American beech 17 0 Musclewood Ironwood 0 33 Black birch

21 Table 3: Attributes of downed woody debris (DWD) and snags in Stand 16, Shelburne Farms, VT. DWD Snags Volume Biomass Volume Biomass DBH Density (ft 3 /ac) (t/ac) (ft 3 /ac) (t/ac) (in) (#/ac) Table 4: Richness, diversity and evenness for Stand 16, Shelburne Farms, VT. Layer Richness Diversity (H ) Evenness Overstory Regeneration Trees per Acre WP SM WA BB IW Other Diameter Class (inches) Figure 1: Diameter distribution of overstory trees in Stand 16, Shelburne Farms, VT. Other category includes American elm, black cherry, bitternut hickory, bigtooth aspen, Norway maple, and Shagbark hickory. Live tree biomass for Stand 16, Shelburne Farms, VT: 86.3 tons/ac 21

22 Stand Structure in Shelburne Farms: Stand 17 Carlina Arango, Elizabeth Bannar, Diana Gurvich, Jamie Waterman Main Findings: Largely dominated by small sugar maple (5-11in diameter classes) Sugar maple had high importance in Stand 17, including regeneration layer Management Recommendations: Being next to the sugar bush already located at Shelburne Farms, Stand 17 provides possible expansion in the future given the high density of small sugar maple trees present Thinning from below would help encourage the growth of these trees Table 1: Overstory tree values per acre, basal area per acre, Importance Values, and average diameter at breast height in Stand 17, Shelburne Farms, VT. Species TPA BA (ft 2 /ac) IV DBH (in) Sugar maple American beech Black birch Bitternut hickory American basswood Ironwood Paper Birch Total Table 2: Seedlings and sapling densities for Stand 17, Shelburne Farms, VT. Italicized species are non-native invasives. Species Seedlings (#/ac) Saplings (#/ac) Sugar maple Glossy buckthorn 8 0 Bitternut hickory American beech Choke cherry 25 0 Ironwood 8 17 Table 3: Attributes of downed woody debris (DWD) and snags in Stand 17, Shelburne Farms, VT. DWD Snags Volume Biomass Volume Biomass DBH Density (ft 3 /ac) (t/ac) (ft 3 /ac) (t/ac) (in) (#/ac)

23 Table 4: Richness, diversity and evenness for stand 17 in Shelburne Farms, VT. Layer Richness Diversity (H ) Evenness Overstory Regeneration Trees Per Acre SM BH BB AB Other Diameter Class (inches) Figure 1: Diameter distribution of overstory trees in Stand 17, Shelburne Farms, VT. Other category includes American beech, basswood, and paper birch. Live tree biomass for Stand 17, Shelburne Farms, VT: 80.5 tons/ac 23