1 00:00:03,120 --> 00:00:06,164 All right, thanks everyone for being here. 2 00:00:06,164 --> 00:00:09,540 If you came to see Bill Keaton's talk, 3 00:00:09,540 --> 00:00:11,696 I'm sorry to disappoint you that I am not Bill, 4 00:00:11,696 --> 00:00:14,200 but he unfortunately at the last minute 5 00:00:15,060 --> 00:00:16,110 had to miss the conference today. 6 00:00:16,110 --> 00:00:18,960 I know he's sorry he can't be here with everyone, 7 00:00:18,960 --> 00:00:21,690 but I'm a PhD student in his lab 8 00:00:21,690 --> 00:00:24,418 and he asked me to give his talk for him. 9 00:00:24,418 --> 00:00:27,000 So I'm gonna be talking about some research 10 00:00:27,000 --> 00:00:29,820 that our lab has been doing over the past several years 11 00:00:29,820 --> 00:00:32,298 looking at how riparian forest structure 12 00:00:32,298 --> 00:00:36,368 impacts woody debris in streams. 13 00:00:36,368 --> 00:00:41,368 And this is a project that was primarily led by Bill 14 00:00:41,370 --> 00:00:44,070 and then a former master student, Hannah Kirkmeyer. 15 00:00:44,070 --> 00:00:46,620 And I've been involved in kind of the later stages. 16 00:00:47,580 --> 00:00:50,850 So just to give you some background 17 00:00:50,850 --> 00:00:52,680 a little bit on Woody debris, 18 00:00:52,680 --> 00:00:56,070 it's obviously a very popular topic right now 19 00:00:56,070 --> 00:00:58,170 after all of the flooding this summer. 20 00:00:58,170 --> 00:00:59,790 But large woody debris 21 00:00:59,790 --> 00:01:03,046 has a lot of really important functions within streams. 22 00:01:03,046 --> 00:01:05,550 It creates habitat complexity, 23 00:01:05,550 --> 00:01:06,906 which can be important for fish 24 00:01:06,906 --> 00:01:10,044 and macro invertebrate habitat 25 00:01:10,044 --> 00:01:12,613 that provides sites for nutrient processing 26 00:01:12,613 --> 00:01:15,120 and increases the roughness 27 00:01:15,120 --> 00:01:17,850 or the complexity of the stream channel, 28 00:01:17,850 --> 00:01:20,460 which has important implications for flood resilience. 29 00:01:20,460 --> 00:01:22,520 If you look at the photo here on the right, 30 00:01:22,520 --> 00:01:26,130 that's from Hubbard Brook Experimental Forest, 31 00:01:26,130 --> 00:01:28,200 and you can see all that wood in the stream 32 00:01:28,200 --> 00:01:29,847 is really creating a much more complex 33 00:01:29,847 --> 00:01:31,503 and rough environment. 34 00:01:32,790 --> 00:01:34,740 Now, a lot of research has shown that 35 00:01:34,740 --> 00:01:38,210 large wood recruitment to streams is positively correlated 36 00:01:38,210 --> 00:01:41,255 with forest age and structural development. 37 00:01:41,255 --> 00:01:45,996 The figure here on the bottom left shows on the X axis, 38 00:01:45,996 --> 00:01:48,627 the stand age of riparian forests. 39 00:01:48,627 --> 00:01:50,004 And then on the Y axis, 40 00:01:50,004 --> 00:01:53,700 the frequency of woody debris and streams. 41 00:01:53,700 --> 00:01:55,470 You can see there's a very strong relationship here 42 00:01:55,470 --> 00:01:59,531 where older forests store more wood at in their streams. 43 00:01:59,531 --> 00:02:04,230 And as forests age undeveloped structurally, 44 00:02:04,230 --> 00:02:07,710 the recruitment of wood two streams happens 45 00:02:07,710 --> 00:02:09,120 both through density, 46 00:02:09,120 --> 00:02:11,671 dependent mortality like south thinning 47 00:02:11,671 --> 00:02:14,880 and through density independent mortality 48 00:02:14,880 --> 00:02:16,593 such as disturbance gaps. 49 00:02:17,796 --> 00:02:19,860 But where this gets a little more complicated 50 00:02:19,860 --> 00:02:22,800 is because structural development 51 00:02:22,800 --> 00:02:25,310 that provides a lot of wood to streams 52 00:02:25,310 --> 00:02:27,690 occurs over multiple pathways 53 00:02:27,690 --> 00:02:30,218 depending on disturbance type, stand conditions, 54 00:02:30,218 --> 00:02:31,849 all sorts of things. 55 00:02:31,849 --> 00:02:34,710 Typically, you know, we think about stand development 56 00:02:34,710 --> 00:02:37,260 in northern hardwood Conifer forest is following 57 00:02:37,260 --> 00:02:40,200 sort of the classic old field succession model 58 00:02:40,200 --> 00:02:42,120 like you see at the top of this figure 59 00:02:42,120 --> 00:02:44,460 where trees come back, they grow, 60 00:02:44,460 --> 00:02:46,230 and then eventually later in succession 61 00:02:46,230 --> 00:02:49,949 you have the development of gaps and downed wood. 62 00:02:49,949 --> 00:02:52,800 But in recent years, in recent decades, 63 00:02:52,800 --> 00:02:56,200 we've learned that there are many more complex pathways 64 00:02:56,200 --> 00:02:58,326 through which stand development can occur. 65 00:02:58,326 --> 00:02:59,614 A couple of which are, 66 00:02:59,614 --> 00:03:03,960 that are theorized are shown here in the middle 67 00:03:03,960 --> 00:03:06,164 and bottom panel of this figure. 68 00:03:06,164 --> 00:03:07,860 But despite the fact that we know 69 00:03:07,860 --> 00:03:09,886 there are these multiple pathways of stand development, 70 00:03:09,886 --> 00:03:11,790 we don't have great paradigms 71 00:03:11,790 --> 00:03:14,610 to understand exactly how they work. 72 00:03:14,610 --> 00:03:18,090 And so this made us interested in, 73 00:03:18,090 --> 00:03:21,210 okay, how does stand development under different pathways 74 00:03:21,210 --> 00:03:24,720 impact wood loading and streams? 75 00:03:24,720 --> 00:03:27,900 And we know that one place that there is a 76 00:03:27,900 --> 00:03:30,480 sort of unique stand development pathway occurring 77 00:03:30,480 --> 00:03:32,583 is at the Hubbard Brook Experimental Forest, 78 00:03:32,583 --> 00:03:35,130 thanks in large part to some work by Charlie Coville 79 00:03:35,130 --> 00:03:36,416 who I see out there. 80 00:03:36,416 --> 00:03:40,290 Hubbard Brook was partially harvested 81 00:03:40,290 --> 00:03:42,990 in the late 1800s and early 1900s, 82 00:03:42,990 --> 00:03:47,316 leaving some remnant trees that many of which remain today. 83 00:03:47,316 --> 00:03:49,108 And so this led us to wonder, 84 00:03:49,108 --> 00:03:51,270 how does stand development 85 00:03:51,270 --> 00:03:53,612 associated with such partial harvesting 86 00:03:53,612 --> 00:03:55,634 and the retention of large trees 87 00:03:55,634 --> 00:03:59,973 impact large woody debris recruitment into streams? 88 00:04:02,027 --> 00:04:05,088 So to look at this, we, as I mentioned, 89 00:04:05,088 --> 00:04:07,685 went to the Hubbard Brook experimental forest. 90 00:04:07,685 --> 00:04:09,101 It's a mature forest. 91 00:04:09,101 --> 00:04:12,930 And the land use history, as I was mentioning, 92 00:04:12,930 --> 00:04:16,800 involved a lot of heavy logging for spruce trees 93 00:04:16,800 --> 00:04:18,171 at the turn of the 20th century 94 00:04:18,171 --> 00:04:21,239 and then some logging as well of hardwoods. 95 00:04:21,239 --> 00:04:24,827 But this left a number of undesirable hardwoods 96 00:04:24,827 --> 00:04:28,129 and left advanced regeneration release 97 00:04:28,129 --> 00:04:30,810 creating these legacy trees, 98 00:04:30,810 --> 00:04:33,063 like you can see in this image here. 99 00:04:34,015 --> 00:04:39,015 This creates a forest that has a variety of tree sizes 100 00:04:39,547 --> 00:04:41,820 and some horizontal complexity. 101 00:04:41,820 --> 00:04:43,890 I mean nothing approaching old growth, 102 00:04:43,890 --> 00:04:45,390 but it has some complexity 103 00:04:45,390 --> 00:04:46,770 as you can see in this photo here, 104 00:04:46,770 --> 00:04:48,940 variety of tree diameters 105 00:04:48,940 --> 00:04:53,280 left some large trees that are old enough and big enough 106 00:04:53,280 --> 00:04:55,170 to have epicormic growth. 107 00:04:55,170 --> 00:04:57,600 And then what we're interested in, 108 00:04:57,600 --> 00:04:59,754 these large trees eventually fall over 109 00:04:59,754 --> 00:05:02,880 and often recruit into streams 110 00:05:02,880 --> 00:05:04,468 like you see with this ash tree here, 111 00:05:04,468 --> 00:05:07,534 and remain in the stream, 112 00:05:07,534 --> 00:05:09,300 adding a lot of woody debris 113 00:05:09,300 --> 00:05:11,550 and also collecting a lot of wood 114 00:05:11,550 --> 00:05:14,250 that would otherwise move through the system, 115 00:05:14,250 --> 00:05:16,700 creating a debris dam like you see in this photo. 116 00:05:17,820 --> 00:05:19,230 So because of that, 117 00:05:19,230 --> 00:05:20,805 and what we know about this recruitment process, 118 00:05:20,805 --> 00:05:23,706 we hypothesize that forest structure 119 00:05:23,706 --> 00:05:25,850 and particularly legacy trees 120 00:05:25,850 --> 00:05:29,520 are influencing the variability that we'd find 121 00:05:29,520 --> 00:05:32,343 in wood loading and streams across Hubbard Brook. 122 00:05:33,570 --> 00:05:37,065 So to assess this, we selected 13 headwater streams 123 00:05:37,065 --> 00:05:39,450 in the Hubbard Brook Valley. 124 00:05:39,450 --> 00:05:42,046 Each reach that we sampled was 300 meters long. 125 00:05:42,046 --> 00:05:45,540 These were all first or second order streams, 126 00:05:45,540 --> 00:05:48,100 so about three to five meters in width. 127 00:05:48,100 --> 00:05:50,163 And they were unmanaged. 128 00:05:51,510 --> 00:05:52,830 We had field crews go out 129 00:05:52,830 --> 00:05:56,091 and they sampled all of the wood within the stream reaches. 130 00:05:56,091 --> 00:05:58,620 And to count as large wood, 131 00:05:58,620 --> 00:06:01,260 a piece of wood must be at least 10 centimeters in diameter 132 00:06:01,260 --> 00:06:02,787 and at least a meter long. 133 00:06:02,787 --> 00:06:06,436 And then the field crews also sampled the riparian forest 134 00:06:06,436 --> 00:06:09,450 setting up four random plots at each site 135 00:06:09,450 --> 00:06:13,350 to assess forest structure and composition. 136 00:06:13,350 --> 00:06:16,170 So then we could understand how that played a role 137 00:06:16,170 --> 00:06:17,170 in the wood loading. 138 00:06:18,510 --> 00:06:21,225 So to get into some of the results first about wood loading, 139 00:06:21,225 --> 00:06:24,270 these two figures here show you 140 00:06:24,270 --> 00:06:26,229 each stream reach that we sampled. 141 00:06:26,229 --> 00:06:30,870 And on the top is the volume of woody debris in the stream 142 00:06:30,870 --> 00:06:32,870 and on the bottom is the frequency of woody debris. 143 00:06:32,870 --> 00:06:36,459 So that's number of pieces per 100 meters of stream length. 144 00:06:36,459 --> 00:06:41,400 And we broke each stream up into 50 meter sub-segments 145 00:06:41,400 --> 00:06:43,470 to try to understand some of the variabilities. 146 00:06:43,470 --> 00:06:45,195 That's why you see there are error bars 147 00:06:45,195 --> 00:06:49,140 and ranges on these graphs. 148 00:06:49,140 --> 00:06:50,850 But the first thing to notice here 149 00:06:50,850 --> 00:06:52,470 and kind of the most important thing 150 00:06:52,470 --> 00:06:53,763 is that there's a lot of variability. 151 00:06:53,763 --> 00:06:56,820 There's variability between stream reaches. 152 00:06:56,820 --> 00:06:58,744 So those black bars are the medians. 153 00:06:58,744 --> 00:07:01,260 You can see those vary quite a bit 154 00:07:01,260 --> 00:07:04,889 from a stream like falls to one like Cushman. 155 00:07:04,889 --> 00:07:06,930 But then there's also a lot of variability 156 00:07:06,930 --> 00:07:07,860 within each stream. 157 00:07:07,860 --> 00:07:10,132 So individual 50 meter segments 158 00:07:10,132 --> 00:07:15,064 varied a lot within this broader 300 meter long reach. 159 00:07:15,064 --> 00:07:18,690 And then to understand how forest structure 160 00:07:18,690 --> 00:07:21,270 impacted that variability, 161 00:07:21,270 --> 00:07:25,140 we found we ran Bayesian generalized linear mixed models, 162 00:07:25,140 --> 00:07:26,392 which is kind of a mouthful 163 00:07:26,392 --> 00:07:31,392 and analyzing these 50 meter sub reaches of the stream. 164 00:07:32,057 --> 00:07:35,130 And then we made models using 165 00:07:35,130 --> 00:07:38,400 28 different predictor variables of forest structure 166 00:07:38,400 --> 00:07:40,068 and stream geomorphology. 167 00:07:40,068 --> 00:07:42,060 And then within those models, 168 00:07:42,060 --> 00:07:44,310 we picked out the most parsimonious model 169 00:07:44,310 --> 00:07:46,890 describing the wood, loading the wood, 170 00:07:46,890 --> 00:07:49,250 the frequency and volume of wood in these streams 171 00:07:49,250 --> 00:07:52,773 using the expected log predictive density. 172 00:07:53,815 --> 00:07:55,560 So what do we find? 173 00:07:55,560 --> 00:07:57,979 This here, this figure on the right is, 174 00:07:57,979 --> 00:07:59,236 there's a lot in here, 175 00:07:59,236 --> 00:08:01,560 but basically what it's showing is 176 00:08:01,560 --> 00:08:04,338 each of those panels is one of the predictors, 177 00:08:04,338 --> 00:08:06,750 one of the parameters that was included 178 00:08:06,750 --> 00:08:10,771 in the best fitting model to describe woody debris volume 179 00:08:10,771 --> 00:08:12,933 in these streams. 180 00:08:12,933 --> 00:08:17,070 But among these, so among these nine, 181 00:08:17,070 --> 00:08:18,450 one of the most important ones 182 00:08:18,450 --> 00:08:19,710 is the one that's circled up there, 183 00:08:19,710 --> 00:08:23,460 which is the density of big trees in the riparian forest. 184 00:08:23,460 --> 00:08:25,860 And big trees in the northeast 185 00:08:25,860 --> 00:08:27,090 and kind of the east in general 186 00:08:27,090 --> 00:08:30,143 are trees greater than 50 centimeters in diameter. 187 00:08:30,143 --> 00:08:32,156 So what you can see in that circled panel, 188 00:08:32,156 --> 00:08:34,636 these are marginal effects graphs, 189 00:08:34,636 --> 00:08:37,080 which basically means it's showing you the impact 190 00:08:37,080 --> 00:08:40,710 of each parameter on woody debris volume. 191 00:08:40,710 --> 00:08:42,030 So in that circled one, 192 00:08:42,030 --> 00:08:44,760 you can see there's this a positive relationship here, 193 00:08:44,760 --> 00:08:46,920 meaning that a higher density of big trees 194 00:08:46,920 --> 00:08:50,108 in the riparian forest is related strongly 195 00:08:50,108 --> 00:08:53,693 to the volume of woody debris in the stream. 196 00:08:53,693 --> 00:08:56,137 There's a number of other things involved in this model. 197 00:08:56,137 --> 00:08:58,100 I don't have time to get into all of those. 198 00:08:58,100 --> 00:09:00,403 But another interesting one is on the bottom right, 199 00:09:00,403 --> 00:09:02,580 which hopefully you can read there, 200 00:09:02,580 --> 00:09:04,890 that's the standard deviation of basal area 201 00:09:04,890 --> 00:09:05,984 in the riparian forest. 202 00:09:05,984 --> 00:09:08,700 And that's interesting 'cause you can see there is, 203 00:09:08,700 --> 00:09:10,260 again this positive relationship 204 00:09:10,260 --> 00:09:12,977 where a higher standard deviation in the riparian, 205 00:09:12,977 --> 00:09:16,454 basal area in the riparian forest led to 206 00:09:16,454 --> 00:09:19,650 or is related to more wood in the streams. 207 00:09:19,650 --> 00:09:21,480 So this suggests that maybe there's some element 208 00:09:21,480 --> 00:09:23,770 of patch complexity within the riparian forest 209 00:09:23,770 --> 00:09:27,843 that plays a role in increasing woody debris volume as well. 210 00:09:28,832 --> 00:09:31,771 Then when we go on to look at the frequency of wood, 211 00:09:31,771 --> 00:09:35,040 this was the best model describing wood frequency. 212 00:09:35,040 --> 00:09:37,835 So again, that's number of pieces of wood 213 00:09:37,835 --> 00:09:41,100 per stream length, unit of stream length. 214 00:09:41,100 --> 00:09:45,113 And again here the most important predictor in this model 215 00:09:45,113 --> 00:09:47,400 was the density of big trees, 216 00:09:47,400 --> 00:09:48,810 again with a positive relationship. 217 00:09:48,810 --> 00:09:52,950 So we're seeing that big tree density increases 218 00:09:52,950 --> 00:09:55,680 or is related to increasing wood volume 219 00:09:55,680 --> 00:09:58,053 and frequency in the streams. 220 00:09:59,514 --> 00:10:01,560 There's a couple other things in here I just wanna point out 221 00:10:01,560 --> 00:10:03,558 that we're still trying to untangle. 222 00:10:03,558 --> 00:10:06,810 So if you look, you see that quadratic mean diameter 223 00:10:06,810 --> 00:10:09,815 is included, that's the top left panel I think. 224 00:10:09,815 --> 00:10:11,713 And there's a positive relationship there 225 00:10:11,713 --> 00:10:14,460 which would suggest that okay, 226 00:10:14,460 --> 00:10:15,870 larger trees are important 227 00:10:15,870 --> 00:10:17,946 for increasing wood volume and streams. 228 00:10:17,946 --> 00:10:20,127 However, if we go back and look here, 229 00:10:20,127 --> 00:10:23,730 we can see that when we're looking at 230 00:10:23,730 --> 00:10:25,290 volume rather than frequency, 231 00:10:25,290 --> 00:10:29,730 the bottom middle panel is quadratic mean diameter 232 00:10:29,730 --> 00:10:31,440 and there's actually a negative relationship here. 233 00:10:31,440 --> 00:10:34,200 So there seems to be something weird going on with that 234 00:10:34,200 --> 00:10:37,860 where it's negatively related to wood volume in the stream, 235 00:10:37,860 --> 00:10:40,200 positively related to wood frequency in the stream. 236 00:10:40,200 --> 00:10:43,756 So still sort of untangling that and why that might be. 237 00:10:43,756 --> 00:10:46,950 And then also there's this very interesting 238 00:10:46,950 --> 00:10:50,178 negative relationship with dead tree density 239 00:10:50,178 --> 00:10:53,400 and woody debris volume in the stream. 240 00:10:53,400 --> 00:10:56,130 Our hypothesis about this is you might think, 241 00:10:56,130 --> 00:10:58,684 okay, if you have more snags in the riparian forest, 242 00:10:58,684 --> 00:11:00,861 you'll have more wood in the stream. 243 00:11:00,861 --> 00:11:03,660 But our hypothesis about this negative relationship 244 00:11:03,660 --> 00:11:05,970 is that there's maybe a time element here. 245 00:11:05,970 --> 00:11:07,526 So perhaps what is happening is 246 00:11:07,526 --> 00:11:12,203 in a forest that has few snags in the riparian zone, 247 00:11:12,203 --> 00:11:15,390 there perhaps used to be more snags 248 00:11:15,390 --> 00:11:17,490 that have already recruited into the stream. 249 00:11:17,490 --> 00:11:20,790 So that stream would have fewer snags in the riparian area 250 00:11:20,790 --> 00:11:24,150 but more in the stream. 251 00:11:24,150 --> 00:11:25,500 So that's our hypothesis. 252 00:11:25,500 --> 00:11:26,585 We haven't directly tested it, 253 00:11:26,585 --> 00:11:29,373 but an interesting relationship there. 254 00:11:30,501 --> 00:11:34,140 So our main conclusions, what are the takeaways here? 255 00:11:34,140 --> 00:11:37,486 The big one is that remnant old legacy trees 256 00:11:37,486 --> 00:11:40,950 appear to enhance and be related to 257 00:11:40,950 --> 00:11:43,160 woody debris volume and frequency 258 00:11:43,160 --> 00:11:46,170 in low order streams at Hubbard Brook. 259 00:11:46,170 --> 00:11:48,997 This makes a lot of sense conceptually 260 00:11:48,997 --> 00:11:51,780 because if these images on the left 261 00:11:51,780 --> 00:11:53,250 are not from Hubbard Brook, 262 00:11:53,250 --> 00:11:54,900 they're from actually old growth forests. 263 00:11:54,900 --> 00:11:58,215 But you can see how when these large stems 264 00:11:58,215 --> 00:12:01,159 recruit into the stream, they're very stable. 265 00:12:01,159 --> 00:12:03,420 So when you have a big tree that falls in, 266 00:12:03,420 --> 00:12:05,334 it often stays there for a long period of time. 267 00:12:05,334 --> 00:12:09,519 These also have a lower surface area to volume ratio, 268 00:12:09,519 --> 00:12:11,716 which means decomposition occurs more slowly 269 00:12:11,716 --> 00:12:14,670 and they're very important for collection 270 00:12:14,670 --> 00:12:16,170 of lots of smaller pieces of wood, 271 00:12:16,170 --> 00:12:17,970 so creating debris dams. 272 00:12:17,970 --> 00:12:20,402 And so basically these large trees 273 00:12:20,402 --> 00:12:23,610 and their eventual recruitment into streams 274 00:12:23,610 --> 00:12:25,620 may translate into effects on 275 00:12:25,620 --> 00:12:27,685 wood related in-stream processes. 276 00:12:27,685 --> 00:12:30,851 As I mentioned, we think that there's, 277 00:12:30,851 --> 00:12:33,180 that this might be partially related 278 00:12:33,180 --> 00:12:36,480 to some atypical stand development pathways at Hubbard Brook 279 00:12:36,480 --> 00:12:37,486 and we're looking into that. 280 00:12:37,486 --> 00:12:39,396 And then from a management perspective, 281 00:12:39,396 --> 00:12:44,396 retention forestry that keeps big trees in riparian zones 282 00:12:44,400 --> 00:12:48,144 may be important for long-term wood benefits. 283 00:12:48,144 --> 00:12:49,648 I just have about 30 seconds left 284 00:12:49,648 --> 00:12:52,050 so I'm not gonna go into this in a lot of detail, 285 00:12:52,050 --> 00:12:54,779 but this is just sort of an idea 286 00:12:54,779 --> 00:12:56,741 to show you what we're continuing to work on. 287 00:12:56,741 --> 00:13:00,210 We're interested in how the riparian forest now 288 00:13:00,210 --> 00:13:01,680 is impacting the functions 289 00:13:01,680 --> 00:13:05,118 provided by these woody debris in the stream. 290 00:13:05,118 --> 00:13:06,420 So we're doing some research 291 00:13:06,420 --> 00:13:08,392 into the carbon stored by this wood in streams. 292 00:13:08,392 --> 00:13:11,132 We're finding again here, big trees, 293 00:13:11,132 --> 00:13:13,905 very important for the carbon storage of wood in streams. 294 00:13:13,905 --> 00:13:16,682 And then on the right here, 295 00:13:16,682 --> 00:13:20,199 we did an analysis comparing the carbon stored 296 00:13:20,199 --> 00:13:23,250 in wood in streams at mature forest, 297 00:13:23,250 --> 00:13:24,360 so at Hubbard Brook 298 00:13:24,360 --> 00:13:25,770 compared to an old growth forest 299 00:13:25,770 --> 00:13:26,880 and found that the old growth forest 300 00:13:26,880 --> 00:13:29,310 stored about five times the amount of carbon. 301 00:13:29,310 --> 00:13:31,230 So this may have future implications 302 00:13:31,230 --> 00:13:33,270 for carbon dynamics and streams 303 00:13:33,270 --> 00:13:36,630 as well as the potential uses a natural climate solution 304 00:13:36,630 --> 00:13:38,823 as forests age and develop. 305 00:13:40,290 --> 00:13:41,123 Let's see. 306 00:13:41,123 --> 00:13:42,870 And I just want to acknowledge our funders, 307 00:13:42,870 --> 00:13:45,372 McIntire-Stennis and National Science Foundation, 308 00:13:45,372 --> 00:13:46,958 all the field crews who helped out 309 00:13:46,958 --> 00:13:48,963 and Hubbard Brook. 310 00:13:50,580 --> 00:13:53,373 -Thanks. -(audience claps) 311 00:14:11,850 --> 00:14:13,350 Thanks for that. That's great. 312 00:14:13,350 --> 00:14:15,540 Very interested in hearing more findings 313 00:14:15,540 --> 00:14:16,560 as you develop them. 314 00:14:16,560 --> 00:14:17,690 So you talked about structure. 315 00:14:17,690 --> 00:14:21,312 Did you also look at diversity, composition, 316 00:14:21,312 --> 00:14:24,420 anything about species in those riparian zones? 317 00:14:24,420 --> 00:14:27,540 And can you comment on some of the preliminary findings? 318 00:14:27,540 --> 00:14:29,023 Yeah, so we have those data. 319 00:14:29,023 --> 00:14:31,530 In terms of this analysis, 320 00:14:31,530 --> 00:14:35,460 the main thing we looked at was the percent conifer, 321 00:14:35,460 --> 00:14:39,420 just because that is, I mean it's a compositional metric, 322 00:14:39,420 --> 00:14:42,379 but it has a strong relationship to structure as well. 323 00:14:42,379 --> 00:14:44,280 Lemme just go back and see. 324 00:14:44,280 --> 00:14:46,830 I don't think that was in, 325 00:14:46,830 --> 00:14:51,729 that was in the model describing woody debris volume. 326 00:14:51,729 --> 00:14:54,600 So there's a negative relationship 327 00:14:54,600 --> 00:14:58,740 between the percent conifer and woody debris volume. 328 00:14:58,740 --> 00:15:00,540 We haven't dived into that too much. 329 00:15:00,540 --> 00:15:01,440 We do have those data. 330 00:15:01,440 --> 00:15:03,740 So it'd be something interesting to look into. 331 00:15:06,870 --> 00:15:07,930 Thanks for that presentation. 332 00:15:07,930 --> 00:15:11,160 Question for you about the snag density 333 00:15:11,160 --> 00:15:13,544 and asking you to look into your crystal ball 334 00:15:13,544 --> 00:15:16,470 and the slide that had the ash on it. 335 00:15:16,470 --> 00:15:18,930 So that potential time lag or anything, 336 00:15:18,930 --> 00:15:21,900 what do you see as the impact of emerald ash bore 337 00:15:21,900 --> 00:15:26,130 on ash trees and then having impacts on our streams? 338 00:15:26,130 --> 00:15:28,931 Yeah, I mean I think that's gonna have a really big, 339 00:15:28,931 --> 00:15:33,000 there's gonna be a large flux of these trees to the streams. 340 00:15:33,000 --> 00:15:34,590 There's been some research done in, 341 00:15:34,590 --> 00:15:37,980 I think West Virginia looking at hemlock (indistinct) 342 00:15:37,980 --> 00:15:40,080 and how that impacted hemlock forests. 343 00:15:40,080 --> 00:15:43,920 And there was a bit of a time lag, I believe, 344 00:15:43,920 --> 00:15:45,630 from actual infestation 345 00:15:45,630 --> 00:15:47,430 and death of the trees to recruitment. 346 00:15:47,430 --> 00:15:51,330 But that I would imagine is gonna speed up 347 00:15:51,330 --> 00:15:53,430 some of this process of wood recruitment 348 00:15:53,430 --> 00:15:55,888 especially 'cause at a lot of places, 349 00:15:55,888 --> 00:15:58,530 the ash trees are some of the larger trees 350 00:15:58,530 --> 00:15:59,910 left in the riparian forest. 351 00:15:59,910 --> 00:16:04,744 So that may add more large stems to the stream, 352 00:16:04,744 --> 00:16:06,990 which then have this effect of 353 00:16:06,990 --> 00:16:09,030 sort of fueling more wood recruitment 354 00:16:09,030 --> 00:16:12,120 by being stable and forming debris dams. 355 00:16:12,120 --> 00:16:13,770 So as much as we don't wanna lose the ash trees, 356 00:16:13,770 --> 00:16:16,413 I think there may be some benefits to streams. 357 00:16:21,330 --> 00:16:23,438 Hi, have you looked at any correlations 358 00:16:23,438 --> 00:16:27,630 between the amount of large woody debris in the stream 359 00:16:27,630 --> 00:16:30,210 and the in-stream biodiversity, 360 00:16:30,210 --> 00:16:33,240 the macro invertebrate communities or anything like that? 361 00:16:33,240 --> 00:16:36,390 That is something we are starting to do some research on. 362 00:16:36,390 --> 00:16:39,120 We have had someone from Plymouth State come out 363 00:16:39,120 --> 00:16:41,155 and do some sampling on some of these streams. 364 00:16:41,155 --> 00:16:43,588 Don't have any data on our sites. 365 00:16:43,588 --> 00:16:45,690 But my understanding is that 366 00:16:45,690 --> 00:16:48,720 generally having more wood in the stream 367 00:16:48,720 --> 00:16:51,457 does increase macro invertebrate densities. 368 00:16:51,457 --> 00:16:53,942 I'm not sure about diversity. 369 00:16:53,942 --> 00:16:55,620 I would imagine it does, 370 00:16:55,620 --> 00:16:58,173 but I haven't read any studies on that. 371 00:17:04,380 --> 00:17:05,760 Yes, I'm very happy to see that 372 00:17:05,760 --> 00:17:08,010 you have took land use history into account 373 00:17:08,010 --> 00:17:09,090 at Hubbard Brook. 374 00:17:09,090 --> 00:17:10,653 I'm Charlie Cobra by the way. 375 00:17:12,180 --> 00:17:14,310 And it's very interesting. 376 00:17:14,310 --> 00:17:17,009 Hubbard Brook is unique in its land use history 377 00:17:17,009 --> 00:17:21,125 and not only in general but its specific sites, 378 00:17:21,125 --> 00:17:24,060 the different cuts at different times, 379 00:17:24,060 --> 00:17:27,090 at least three different cuts and salvage cuts and whatever. 380 00:17:27,090 --> 00:17:30,512 And it's basically is produced a force that's an oddball. 381 00:17:30,512 --> 00:17:35,512 An oddball that's a hundred years after major management. 382 00:17:35,550 --> 00:17:39,769 And I wonder if that episodic history 383 00:17:39,769 --> 00:17:42,300 is affecting what you have here. 384 00:17:42,300 --> 00:17:44,460 I think it's a wonderful case history 385 00:17:44,460 --> 00:17:46,620 but I don't know how generalizable it is. 386 00:17:46,620 --> 00:17:49,620 All the yellow (indistinct) are falling out. 387 00:17:49,620 --> 00:17:53,259 It's probably overshot the basal area to begin with. 388 00:17:53,259 --> 00:17:56,769 And do you think this process that you're describing 389 00:17:56,769 --> 00:18:01,769 is generalizable to either the original landscape 390 00:18:02,370 --> 00:18:04,830 or the current landscape that's being managed 391 00:18:04,830 --> 00:18:05,943 in a more intense way? 392 00:18:07,110 --> 00:18:08,070 I think it is. 393 00:18:08,070 --> 00:18:10,050 I think as you mentioned though, 394 00:18:10,050 --> 00:18:12,000 because of the unique history at Hubbard Brook, 395 00:18:12,000 --> 00:18:14,490 I think much of the landscape in the Northeast 396 00:18:14,490 --> 00:18:18,079 doesn't have as high a density of these remnant trees. 397 00:18:18,079 --> 00:18:22,560 And the relationship may be harder to pull out 398 00:18:22,560 --> 00:18:25,860 just because there's not enough legacy trees left 399 00:18:25,860 --> 00:18:27,065 to have a huge impact. 400 00:18:27,065 --> 00:18:28,920 But I think at sites 401 00:18:28,920 --> 00:18:31,620 where there was partial harvesting or minimal harvesting, 402 00:18:31,620 --> 00:18:36,620 I think this probably is generalizable to those sites. 403 00:18:36,930 --> 00:18:40,313 And I would imagine that as stand development continues 404 00:18:40,313 --> 00:18:42,960 and we start to have more of these large trees 405 00:18:42,960 --> 00:18:45,745 in places that were clear cut or old ag, 406 00:18:45,745 --> 00:18:47,370 that there would be, 407 00:18:47,370 --> 00:18:51,210 that this relationship would start to be important, 408 00:18:51,210 --> 00:18:53,100 but that may not be for several decades 409 00:18:53,100 --> 00:18:54,993 at sites that were clear cut. 410 00:18:57,390 --> 00:18:59,340 Alrighty, we'll do one more question. 411 00:19:00,780 --> 00:19:03,360 This is Chris Campy, Windham Regional Commission. 412 00:19:03,360 --> 00:19:06,570 I'm here as a planner, not a forester. 413 00:19:06,570 --> 00:19:08,880 But one of the things 414 00:19:08,880 --> 00:19:11,853 I think we need to get the research out quickly 415 00:19:11,853 --> 00:19:16,134 is about the benefits to woody debris and streams 416 00:19:16,134 --> 00:19:18,420 and the impact on flood flows 417 00:19:18,420 --> 00:19:21,197 'cause quickly, right now after these events, 418 00:19:21,197 --> 00:19:23,010 trees are viewed as the enemy 419 00:19:23,010 --> 00:19:25,470 and woody debris is viewed as the enemy 420 00:19:25,470 --> 00:19:28,050 because logically you see it piled up 421 00:19:28,050 --> 00:19:29,610 against culverts and bridges 422 00:19:29,610 --> 00:19:32,092 and trees are viewed as, that is a bad thing. 423 00:19:32,092 --> 00:19:35,460 But what's not necessarily being considered as upstream, 424 00:19:35,460 --> 00:19:36,922 how much stuff is getting caught 425 00:19:36,922 --> 00:19:39,510 by the debris that's already there, 426 00:19:39,510 --> 00:19:42,211 by the standing trees that have been left to stand there 427 00:19:42,211 --> 00:19:45,750 and how that dynamic works. 428 00:19:45,750 --> 00:19:47,667 So just to plea to all of you, 429 00:19:47,667 --> 00:19:49,530 get out in front of your road foreman, 430 00:19:49,530 --> 00:19:51,160 your road crews, your select boards, 431 00:19:51,160 --> 00:19:53,490 you know, maybe specific training 432 00:19:53,490 --> 00:19:55,320 through Vermont local roads and other things 433 00:19:55,320 --> 00:19:58,133 'cause you know, there's this view, 434 00:19:58,133 --> 00:20:01,040 I mean, I think we in this room recognize that, 435 00:20:01,040 --> 00:20:04,740 you know, we need more trees and we need bigger buffers 436 00:20:04,740 --> 00:20:07,320 and we need, you know, to accommodate the flood events 437 00:20:07,320 --> 00:20:08,772 that we've gotten that are coming. 438 00:20:08,772 --> 00:20:12,965 But the intuitive understanding is not that 439 00:20:12,965 --> 00:20:15,241 this is a good thing. 440 00:20:15,241 --> 00:20:19,500 So just wanted to put that out there as a cautionary tale 441 00:20:19,500 --> 00:20:21,150 'cause we're living it right now. 442 00:20:24,090 --> 00:20:24,923 Thank you.