Willow Biomass Silviculture With Mini-rotations

Transcription

1 Willow Biomass Silviculture With Mini-rotations Ralph D. Nyland Department of Forest and Natural Resources Management SUNY College of Environmental Science and Forestry Syracuse, NY Nyland 2010 All rights reserved Use of all or parts of these class notes prohibited without express consent of Ralph D. Nyland Consider this public sentiment Interests in energy independence and greater reliance on renewable sources have encourage a search for new approaches aimed to energy conservation and use of alternate fuels 1

2 to capitalize on carbon-neutral technologies based on renewable sources capitalizing on both old and new approaches Water a traditional source 2

3 brickpix.com Telegraph Media Group - UK also wind Wind Power Ninja papundits but modernizing old technology 3

4 learning and adapting to overcome occasional glitches Other approaches also emerging including both saving and generating energy on site 4

5 often subsidized to encourage investments And inspected regularly for functionality 5

6 Sometimes drawing on necessities of the past even to try methods yet untested for long-term effectiveness and benefit in a modern context Like this based on the sod roofs of old 6

7 and don t forget the forest taking formerly unused materials to generate power 7

8 even opening cost-neutral ways to rehabilitate cutover stands Yet despite the abundance of woody materials from the existing forests the US Department of Energy has promoted an entirely different approach for BIOMASS PRODUCTION based on coppice silviculture 8

9 using artificially established mini-rotation crops of willow not tree willows that grow along streams and rivers 9

10 But shrub willows that develop multiple stool shoots when cut back Note the advantage of willow Christersson et al as a mini-rotation biomass crop 10

11 Hybrid poplars have gained acceptance for pulpwood and other roundwood products yet many clones succumb to canker diseases 11

12 like Hypoxylon and Ceptoria cankers But shrub willows yield high biomass volumes when planted at close spacing... and managed for mini-rotation periods 12

13 not planted on cleared forest sites but in farm lands marginal to normal agricultural production 13

14 Nissen 2001 allowing mechanized operations on tillable soils with 1-, 2-, and 3-year-old copses and access lanes to facilitate operations SUNY-ESF, J. Ballard a farm might have willow crops of staggered ages to insure annual harvest 14

15 using mini-rotations matched to the culmination of mean annual increment for total biomass production Biomass (Tons/acre) 3 Years Willow Biomass Silvicultural System T.A. Volk 15

16 SUNY-ESF herbicide first applied to reduce existing vegetation SUNY-ESF later disked and fitted out like any agricultural crop 16

17 Complete cultivation and weed control essential to success The preparations actually start during the prior dormant season with the harvest of willow canes from a cutting orchard 17

18 Photos by Volk transformed into cuttings for storage below freezing until planting season TA Volk 18

19 then placed into lined boxes for storage until ready Kept below freezing to maintain dormancy and prevent desiccation Photo by Volk 19

20 to protect the unrooted willow cuttings like these Then planting... started from unrooted cuttings 20

21 SUNY-ESF SUNY-ESF or using a step planter to dibble in entire canes automatically cut to proper length before planted SUNY-ESF Using the Swedish double-row planting method D. Robison 21

22 developing a root system during Year 1, with little sprout development Coppiced after the first year to promote vigorous sprouting from the stools... with the shrub willows producing multiple vigorous sprouts after the 1 st -year cutting 22

23 ... like this SUNY-ESF N fertilization done at beginning of 2 nd season 23

24 ... developing rapidly thereafter second season after planting and grown until the culmination of mean annual increment 24

25 note the double row configuration leaving regularly spaced paths for tractor wheels 25

26 and note the difference between clones proper selection essential to optimizing the production for a site 26

27 With one matched to the site... woody biomass (at least 10 dry tons/ac/yr) Then Biomass (Tons/acre) 3 Years regenerating the copse at the culmination of m.a.i. for biomass 27

28 with a harvester like this one cutting a double row with each pass 28

29 drawn in a cut off with this cutter head 29

30 loaded to a trailer common to farm practice 30

31 allowing a farmer to harvest the biomass crop using some already owned equipment and transferred for transport unless conditions allow loading the trailer directly in the field 31

32 Producing chips like this for biofuels the harvester leaves this condition 32

33 with double rows making the harvest more efficient and stools cut close to the ground 33

34 ready to sprout again But will the copse regrow rapidly during the second rotation 34

35 one growing season later multiple sprouts off the old stool 35

36 rapidly restocking the copse then wait two more growing seasons until the culmination of m.a.i. (biomass) 36

37 when ready for coppicing again by three to five rotations the stools spread complicating the harvesting and with damage to the stools 37

38 then dig out the old copse and establish a new planting and plant a new copse 38

39 one option for renewable energy production The twig forest 39