PE EIE[R-Rg RESEARCH ON - HJ Andrews Experimental Forest

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complexity of lake productivity will become apparent. The exponential decay of light intensity is a function of depth . Temperature varies with depth . Although factors leading to lake stratification are well understood, the construction of predictive models for temperature distributions in lakes has only recently begun . Light intensity varies with time, because of seasonal and diurnal patterns plus changing weathe r conditions . There are vertical currents due t o advection and eddy diffusion in lakes (Rile y et al . 1949) . These currents cause temperature, nutrient concentrations, and the population densities to vary with time . We must als o consider feedback mechanisms such as selfshading (Tailing 1960), and local depletion of nutrients by algae . Another interesting feedback mechanis m involves the relation between phytoplankto n and zooplankton densities . The rate of grazing on phytoplankton is determined by zooplankton density and its relative grazing rate (Riley 1947) . On the other hand, the relative grazing rate of zooplankton is a function of phytoplankton density ; a saturated grazing rate is reached at high algal population densities (Holling 1959, Riley 1947) . Zooplankton also influence nutrient availability by excretin g soluble nutrients into the water . In addition to the limnetic plankton communities, there are, in lake ecosystems, littoral communities and, in areas deeper tha n maximal light penetration, benthic communities. The processes that occur in these communities are somewhat different than in th e limnetic community . Littoral communities are similar to terrestrial communities in many respects . Emergent and floating forms have access to atmospheric carbon dioxide . Attached forms have direct access to nutrients held in the sediments ; whereas, limnetic algae are free floating and must depend upon larg e ratios of surface area to volume and upo n passive sinking for efficient nutrient absorption. In littoral areas, herbivores are small , relative to plant size . They consume little of the plant biomass. Littoral plants show seasonal die back, with much material being de - composed . As in terrestrial systems, bacteri a and detritus feeders are the primary agents of nutrient regeneration . Hutchinson and Bowen (1950), in a radiophosphorous study, showed that littoral plants can soak up and hold a large quantity of nutrients . Thus limnetic and littoral plant s do compete for nutrients . The littoral plants are less efficient than algae in absorbing nutrients because of their smaller ratio of surfac e area to volume . The littoral system's ability to hold nutrients (because of slow nutrient re - generation by bacterial decomposition an d relatively small grazing pressure) offsets inefficient nutrient absorption. Phytoplankton , because of their short life span and hig h predation rate, cannot hold nutrients as long as littoral plants, but they are very efficient in absorbing nutrients . Deep benthic communities are made up o f detritus feeders that feed upon seston rainin g down from the productive epilimnion . They may be important in nutrient regeneration (Johannes 1968) . These animals constitute important food sources for higher orde r consumers . A promising theory which may be of great help in generating and answering question s about higher consumers, is that of feeding strategies. For a review of a substantial literature on the subject, see Schoener (1971) . The essence of the theory of feeding strategies i s that selective processes tend to produce populations of organisms which strive to maximiz e their energy (essential nutriment) intake . Predators may accomplish this end in severa l ways; however, it appears reasonable that i t would pay to eat the largest prey or the easiest to capture whenever they are encountered , chasing relatively small difficult-to-catch prey only as a last resort . It is currently being demonstrated that this theory applies to a large variety of animals. The consequence is that one is able not only to predict the foo d habits of individual species but also to estimate their growth dynamics . Acknowledgments The work reported in this paper was supported by National Science Foundation Grant GB-20963 to the Coniferous <strong>Forest</strong> Biome , 35
U .S . Analysis of Ecosystems, International Biological Program . This is Contribution No . 22 to the Coniferous <strong>Forest</strong> Biome, IBP . Literature Cited Holling, C. S. 1959. Some characteristics of simple types of predation and parasitism . Can. Entomol . 91 : 385-398 . Hutchinson, G. E. 1967. A treatise on limnology. Vol. II. Introduction to Lake Biology and the limnoplankton . 1115 p . , illus. New York : John Wiley & Sons . and V. T. Bowen. 1950 . Limnological studies in Connecticut . IX . A quantitative radiochemical study of th e phosphorous cycle in Linsley Pond . Ecology 81 : 194-203 . Johannes, R . E . 1968 . Nutrient regeneration in lakes and oceans . In M . R . Droop and E . J. F. Wood (eds .), Advances in microbiology of the sea, Vol. I, p . 203-213 . New York : Academic Press . Pomeroy, L. R. 1970 . The strategy of mineral cycling . In Annu. rev. of ecol. and syst. , Vol. I, p. 171-190. Palo Alto : Annu. Rev . , Inc . Rhyther, J . H. 1956 . Photosynthesis in the ocean as a function of light intensity . Limnol. & Oceanogr . 1 : 61-70 . Riley, G . A. 1946. Factors controlling phytoplankton populations on Georges Bank . J . Mar . Res . 6 : 54-72 . 1947 . A theoretical analysis o f the zooplankton population on George s Bank . J. Mar. Res . 6: 104-113 . , H. Stommel, and D . F. Bumpus . 1949. Quantitative ecology of the plankto n of the western North Atlantic . Bull . Bingham Oceanogr. Coll. 12 : 1-169 . Schoener, T. W. 1971. Theory of feeding strategies . In Annu. rev. of ecol. and syst . , Vol. II, p. 369-404 . Palo Alto : Annu. Rev . , Inc . Talling, J. F. 1955. The relative growth rates of three plankton diatoms in relation t o underwater radiation and temperature . Ann. Bot. 14 : 329-341 . 1960 . Self-shading effects in natural populations of a planktonic diatom . Wett. Leben 12 : 235-242 . 1961 . Photosynthesis under natural conditions . Ann. Rev. Plant Physiol. 12 : 133-154 . 36
Page 1 and 2: PE EIE[R-Rg RESEARC H O N CONIFEROU
Page 3 and 4: Research on Coniferous Forest Ecosy
Page 5 and 6: Contents SOME BROADER VIEWS OF BIOM
Page 7 and 8: Page AQUATIC PROCESS STUDIES 279 St
Page 9 and 10: Proceedings-Research on Coniferous
Page 11 and 12: directly, to solution of major natu
Page 13 and 14: 4. Nutritional adaptation to enviro
Page 15 and 16: where validation studies could be c
Page 17 and 18: have been developed . Prior to thei
Page 19 and 20: of gross production and respiration
Page 21 and 22: Figure 1 . Aerial photo of Findley
Page 23 and 24: Nutrient levels in stream and lake
Page 25 and 26: Acknowledgments The work reported i
Page 27 and 28: inputs into the lakes . Recent stud
Page 29 and 30: was slightly raised in 1902, the la
Page 31 and 32: climate, surrounding terrestrial en
Page 33 and 34: more similar than between the diffe
Page 35 and 36: The net rate of primary production
Page 37 and 38: community structure and energy flo
Page 39: est adapted organism vacillates bet
Page 43 and 44: successful . Thus we can see modeli
Page 45 and 46: of the external quantities of S wou
Page 47 and 48: Figure 2 . The major subsystems of
Page 49 and 50: subsystems as objects . In addition
Page 51 and 52: several models together to form the
Page 55 and 56: The study areas are located at seve
Page 57 and 58: K m Figure 1 . Watershed 2, H . J.
Page 59 and 60: An alternative way of considering i
Page 61 and 62: Snowmelt A flow chart of the snow a
Page 63 and 64: d Gs Gr = (1 - Ki) d t By integrati
Page 65 and 66: Calibration of Parameter s In gener
Page 67 and 68: model being developed under the Con
Page 69 and 70: Usually, we are interested in the o
Page 71 and 72: LINEAR Y~(T) 2nd ORDER Y2 (T) 3rd O
Page 73 and 74: the watershed. The hydrologic model
Page 77 and 78: considered as part of another food
Page 79 and 80: PRIMARY PRRODUCTIO N ■ FOLIAGE CO
Page 81 and 82: Graham, S. A. 1952. Forest entomolo
Page 83 and 84: ful in regions with relatively unif
Page 85 and 86: epresents the basic linkages betwee
Page 87 and 88: Cleary and Waring 1969, Reed 1971,
Page 89 and 90: vation that species such as Brewer
Page 91 and 92:
Table 3.-Predicted plant response i
Page 93 and 94:
Walker, Reed, Scott, and Webb are c
Page 95 and 96:
Water and Nutrien t Movement Throug
Page 97 and 98:
Here v is the volume of water cross
Page 99 and 100:
2 10 7100 .160 .220 .280 .340 .400
Page 101 and 102:
.0500 .040 0 z .030 0 E L.) 0 .020
Page 103 and 104:
Proceedings-Research on Coniferous
Page 105 and 106:
ment of the flux of ions through th
Page 107 and 108:
Table 2 .-Forest floor composition
Page 109 and 110:
Table 5 .-Monthly amounts of litter
Page 111 and 112:
Figure 2 illustrates how CO 2 produ
Page 113 and 114:
Ballard, T. M. 1968 . Carbon dioxid
Page 115 and 116:
2. How effectively are these chemic
Page 117 and 118:
Table 2 .-Nutrient budget for disso
Page 119 and 120:
Figure 1 . Water content of the sur
Page 121 and 122:
0.12_ _30 rn z 0 Q z w 0 z 0 0 z Q
Page 123 and 124:
_3 0 . Outflow Concentration _ __ R
Page 125 and 126:
0.10_ 0.08 _ Pea k 0.04_ Concentrat
Page 127 and 128:
8J Calciu m 0 I I I I 0.25 0.50 0.7
Page 129 and 130:
water is dominant because flowing w
Page 131 and 132:
Page 133 and 134:
Table 1.-Characteristics of study p
Page 135 and 136:
Z w 2 w J w 3 0 Table 2. Average to
Page 137 and 138:
of the nitrogen was not determined.
Page 139 and 140:
Table 6. Total kg per hectare per y
Page 141 and 142:
through litterfall . More amounts o
Page 143 and 144:
Page 145 and 146:
Figure 3. Two additional carabiners
Page 147 and 148:
1 1 Figure 11 . The climber places
Page 149 and 150:
Figure 16. The spar in use. The sus
Page 151 and 152:
in our example) and the running tot
Page 153 and 154:
Dashed lines are dead branches . Th
Page 155 and 156:
Page 157 and 158:
Table 1.-Transpiration rates, mean
Page 159 and 160:
this case the slopes of activity-ti
Page 161 and 162:
solve equation 2 for Tm since the f
Page 163 and 164:
Page 165 and 166:
ing methods . Every point in the sa
Page 167 and 168:
Patterns in Point Displacemen t Mea
Page 169 and 170:
trees indicates that the coordinate
Page 171 and 172:
data; there is no obvious explanati
Page 173 and 174:
Page 175 and 176:
where C is the percentage cover by
Page 177 and 178:
Table 1.-Epiphyte biomass on the tr
Page 179 and 180:
NZ. 4 50 100 150 EPIPHYTE IMPORTANC
Page 181 and 182:
Table 4.-Biomass estimates (kg) for
Page 183 and 184:
watershed 10 (C . T. Dyrness, perso
Page 185 and 186:
Table 1 .-Some population character
Page 187 and 188:
Table 2 .-Annual litter fall in Col
Page 189 and 190:
Table 4. Biomass and growth increme
Page 191 and 192:
Table 6.-Annual turnover from certa
Page 193 and 194:
Kiil, A. D. 1968. Weight of the fue
Page 195 and 196:
condition differ) ; the turnover ra
Page 197 and 198:
proportionally about the same for e
Page 199 and 200:
Bird Studies The forest birds were
Page 201 and 202:
Further Studies The data provided f
Page 203 and 204:
Terrestrial Process Studies 209
Page 205 and 206:
from theses. The principal processe
Page 207 and 208:
Table 1 .-Saturating light intensit
Page 209 and 210:
at least 0 .06 percent CO 2 . Howev
Page 211 and 212:
Pharis et al. 1967). Again Helms (1
Page 213 and 214:
Effects of Leaf Temperature an d Le
Page 215 and 216:
Literature Cited Baule, H., and C.
Page 217 and 218:
Lopushinsky, W . 1969. Stomatal clo
Page 219 and 220:
Page 221 and 222:
Von Bertalanffy (1969) calls nonsum
Page 223 and 224:
which may be of importance in model
Page 225 and 226:
The first three terms of equation 1
Page 227 and 228:
P = F+ R where F = net assimilation
Page 229 and 230:
Page 231 and 232:
This function is asymptotic to zero
Page 233 and 234:
The important interaction between l
Page 235 and 236:
Page 237 and 238:
(3 = H/AE=yo$/De (3 ) where y is th
Page 239 and 240:
0.4 0.2 v 0 0 w IX -0.2 I- cr -0.4
Page 241 and 242:
Table L-Diurnal energy budget compo
Page 243 and 244:
4 8 10 12 14 16 18 20 22 24 TIME, H
Page 245 and 246:
1970. Evapotranspiration an d meteo
Page 247 and 248:
may bias the results . Meteorologic
Page 249 and 250:
7.4 ppm . The lysimeters at Coshoct
Page 251 and 252:
Acknowledgments The work reported i
Page 253 and 254:
extracted was determined by the wei
Page 255 and 256:
Page 257 and 258:
I - 5 -l o -1 5 HPV 1 10 . 0 I . 6
Page 259 and 260:
Table 1 .- Tukey's w Multiple Compa
Page 261 and 262:
studies in conifers-a review . In J
Page 263 and 264:
permeable to both CO 2 and water va
Page 265 and 266:
insolation (1 cal cm 2 min-1 ) and
Page 267 and 268:
Aquatic Process Studies 279
Page 269 and 270:
stream environments (Krygier and Ha
Page 271 and 272:
S, - 4ydrolo9i c S2 = I¢rr¢strIa
Page 273 and 274:
ingestion variation between individ
Page 275 and 276:
Page 277 and 278:
contribute to detrital compartment
Page 279 and 280:
volume measurement, realizing that
Page 281 and 282:
fer of the indicated carbon-14 trac
Page 283 and 284:
18L LAKE WATER LIGH T 50m1 HOURLY D
Page 285 and 286:
a function of time and space, (b) c
Page 287 and 288:
Page 289 and 290:
Table 1.-Suggested criteria for jud
Page 291 and 292:
Table 4.-Average C, N, and P conten
Page 293 and 294:
during 1963 to 1967 and from Lake S
Page 295 and 296:
greater than 7 .2:1 (16:1 by atoms)
Page 297 and 298:
2 .0 1 .0 0 Si P-N N-Si P-Si P-N-Si
Page 299 and 300:
detectable increase in concentratio
Page 301 and 302:
in lakes . J. Ecol . 29 : 280-329 .
Page 303 and 304:
Woodey 1970 ; Thorne, Reeves, and M
Page 305 and 306:
targets are insonified several time
Page 307 and 308:
This program will automatically cal
Page 309:
The FOREST SERVICE et ; U :' S D pa
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