N in current year needies g/kg

-b)

Rsq⁼0,6480

Rsq⁼0,5041

Figure 3.4. (cont.) Relationships between N-pools and fluxes at intensively monitored sites (for (a), see previous page): (b) N in current year needies vs. nitrogen output; (c) N-pool in organic soil layer vs. N-output. ln ali Figures 3.4 a, b and c aiso data from EXMAN and NITREX sites have been included (sites ADOI-ADI2).

0

The Finnish Envronrnent 27

c)

N

^-p001 in organic layer

g/kg

3.2.2 Relationships between N-pools and fiuxes

The increased N-deposffion can partly be stored in the ecosystem by increasing growth and by increasing N content of soil and vegetation pools. Strong linear correlations have been found between N-flux in both precipitation and throughfali and N content in new needies, needie litter and organic top soil (Gundersen 1995a, Tietema and Beier 1995). It has also been hypothesised that forest ecosystems wiil respond to chronic N additions by increasing the internal cycling of N, Le.

increased mineralisation, increased litterfall N flux and by affecting nitrification processes (Aber et cii. 1989).

Clear relationships could be found between N-output and other ecosystem fluxes and pools of nitrogen aiso using ICP IM data: deposition vs. htterfall (Figure 3.4a); N in current year needies vs. N-output (Figure 3.4b), and the N-pool in organic iayer vs. nitrogen output (Figure 3.4c). In ali figures 3.4a, b and c also data from two ecosystem experiments, EXMAN and MTREX (Tietema and Beier 1995, Wright and Tietema 1995) has been included in order to increase the number of observations and the gradient of Ndeposition. The correlation matrix for the combined dataset is shown in Tahle 3.3.

Muitiple regression techniques were also used to expiain the variance in N leaching. However, many ofthevariables were sfrongly intercorreiated with input N which limits the use of such modeis. Several different combinations were tested, and the foiiowing regression equations gave the most significant results for the combined dataset:

(1) ntot•o ⁼ 0.72Norg+ 0.46ntotJ^-28.24 (n=18, r2=0.82)

(2) ntoto ⁼0.46ntot t + 0.87need c^- 15.00 (n=14, r2=0.79)

(3) ntot•o 1.l3ntoLd ⁺ 0.69N•org^- 15.63 (n=19, r2=0.78)

(4) no3no 0.23(NfIf+ntott) + 1 .34need c- 24.25 (n=11, r2=0.67)

Since a combined dataset of ICP IM, NITREX and EXMÄN were used, the results are similar to those previously obtained (see Tietema and Beier 1995). The output flux of N is highiy correlated with key ecosystem variabies like N deposition, N concentration in current year needies and organic matter, and N flux in iitterfall. By combining the IM data with data from other ecosystem studies the number of sites can be increased and thus more detailed and rehabie assessments become possible.

Ä survey of nifrogen outputs from forested piots and catchments (Dise and Wright 1995) indicated that a combination of input-N and soil pH expiained 87

¾ of the variability in output-N (n=20). The pH-effect (negative correiation) exhibited a marked break at pH 4.2 between sites that retained nitrate and those that leached nitrate. This type of effect could not be observed using the ICP IM data. However, this could he explained by the fact that pH-gradient in the IM data was much smaller with few very acidic sites.

The Finnish Environment 27

Table 3.3. (orrelation matrix between N-pools and fluxes in the combined dataset of.ICP IM, NITREX and EXMAN sites.

NH4N 0 NO3N 0 NIOT 0 NH4N 1 NO3N 1 NT0T 1 NH4N 0 NO3N 0 NTOT 0 NF LF NEEN C NEED 8

NH4N 0 1.0000 ^.7868 .9739 .7762 .6339 ,7746 .6927 .6036 .6277 .6114 .6389 .8984

— ( ⁵⁰⁾ ) ⁵⁰⁾ ⁾ ⁵⁰⁾ ( 36) ( 36) ( 36) 1 32) 36) 36) 1 17) 1 18) 12

7= 8= .000 7 .000 7 .000 7 .000 7= .000 P .000 7= .000 ?= .000 P .009 7= .004 P .005

1403)1 0 .7868 1.0000 .9058 .6072 .7489 .6863 6117 5560 .6760 7421 4863 .7555

50) 50) ) ⁵⁰⁾ 1 36) ( 36) ) ³⁶⁾ ^t ³²⁾ ^t ³⁶⁾ ) ³⁶⁾ ¹⁷⁾ 1 ¹⁸⁾ t 12)

7= .000 7= 2= .000 7= .000 6= .000 7= .000 7= .000 7= .000 7= .000 7= .001 2= .041 P.’ .005

NTOT 0 .9739 .9058 1.0000 .7578 .7017 7826 .7003 .6199 .6453 .6748 .6089 .8624

— t ⁵⁰⁾ ⁵⁰⁾ ¹ ⁵⁰⁾ ^t ³⁶⁾ ⁾ ³⁶⁾ ⁾ ³⁶⁾ ¹ ³²⁾ ⁽ ³⁶⁾ ¹ ³⁶⁾ ^t ¹⁷⁾ ¹ ¹⁸⁾ ⁽

12)

7= .000 9= .000 2= 9= .000 7= .000 9= .000 7= .000 9= .000 7= .000 P= .003 6= .007 7= .000

88414 1 .7762 .6072 .7578 1.0000 .7538 ,9780 .5250 .7731 .7856 .6694 .6153 .9298

36) ) 36) ) 36) ) 36) ) 36) ) 35) ) 23) ( 25) 1 25) 1 17) 1 18) ( 12)

7= .000 7= .000 7= .000 P . 7= .000 P .000 7= .010 7= .000 9= .000 2 .003 P .007 P .000

8038 1 .6339 .7489 .7017 .7538 1.0000 .8743 .3749 .6437 .6509 .7849 .4735 .6749

— 1 ³⁶⁾ ⁾ ³⁶⁾ ⁾ ³⁶⁾ ⁾ ³⁶⁾ ¹ ³⁶⁾ ⁾ ³⁶⁾ ⁽ ²³⁾ ¹ ²⁵⁾ ¹ ²⁵⁾ ⁽ ¹⁷⁾ ¹ ¹⁸⁾ ¹

12)

P .000 7= .000 P .000 p= ,ooo p= , 9= .000 7= .078 7= .001 P .000 7 .000 7 .047 7 .016

17801 1 .7746 .6863 .7826 .9780 .8743 1,0000 .5047 .7679 .7793 .7306 .6038 .8946

— ) 36) t 36) ) 36) 1 36) ( 35) ( 36) ( 23) 1 25) 1 25) 1 17) 1 18) 1 12)

7= .000 7= .000 7= .000 P .000 7 .000 9= , 7 .014 7= .000 7= .000 7 .001 P .005 7= .000

NH4N 0 .6917 .6117 .7003 .5250 .3749 .5047 1,0000 .4864 .5378 .5923 .6388 .7171

32) 1 32) ) ³²⁾ ¹ ²³⁾ ) ²³⁾ ) ²³⁾ ⁾ ³³⁾ ⁾ ³³⁾ ⁾ ³³⁾ ¹ ¹⁴⁾ ¹ ¹³⁾ ¹ ¹⁰⁾

7= .000 P .000 P .000 7= .010 7= .078 7= .014 P . 7= .004 7 .001 F .026 7= .019 7= .020

8038 0 .6036 .5560 .6199 .7731 6437 .7679 .4864 1,0000 .9982 .5382 .6857 .8314

— ) ³⁶⁾ ⁾ ³⁶⁾ ) ³⁶⁾ ¹ ²⁵⁾ ¹ ²⁵⁾ ⁾ ²⁵⁾ 1 ³³⁾ ) 37) ) ³⁷⁾ 1 ¹⁴⁾ 1 ¹⁴⁾ ) ¹⁰⁾

9= .000 9= .000 7= .000 7= .000 9= .001 P= .000 7= .004 7= . 7= .000 7= .047 7= .007 7= .003

NTOT 0 .6297 .5760 .6453 .7856 .6509 .7793 .5378 .9982 1,0000 .5497 .6940 .8303

— ) ³⁶⁾ ) ³⁶⁾ 1 36) 1 25) ) ²⁵⁾ ) ²⁵⁾ ⁾ ³³⁾ ⁾ ³⁷⁾ ⁾ ³⁷⁾ ¹ ¹⁴⁾ ) ¹⁴⁾ ¹ ¹⁰⁾

7 .000 9= .000 P .000 2= .000 7= .000 P .000 7 .001 7= .000 P . 7= .042 P= .006 7= .003

NF LF .6114 .7421 .6748 .6694 .7849 .7306 .5923 .5382 .5497 1,0000 .5385 .7909

— ) ¹⁷⁾ ) ¹⁷⁾ ¹ ¹⁷⁾ ¹ ¹⁷⁾ ) ¹⁷⁾ ⁾ ¹⁷⁾ ¹ ¹⁴⁾ t ¹⁴⁾ ¹ ¹⁴⁾ 1 ¹⁸⁾ 1 ¹⁴⁾ ) ¹⁰⁾

P .009 7= .001 7= .003 7= .003 7= .000 7= .001 7= .026 7= .047 7= .042 7= , 7= .047 2= .006

NEED 0 .6369 .4863 .6089 .6153 .4735 .6038 .6388 .6857 .6940 .5385 1.0000 .9818

— 1 ¹⁸⁾ 1 18) 1 ¹⁸⁾ 1 ¹⁸⁾ 1 ¹⁸⁾ ) ¹⁸⁾ 1 ¹³⁾ t ¹⁴⁾ 1 ¹⁴⁾ ( ¹⁴⁾ 1 ¹⁸⁾ ¹ ¹²⁾

7= .004 9= .041 7= .007 7= .007 9= .047 7= .008 7= .019 7= .007 7” .006 7= .047 7” . 2= .000

NEED 8 .8984 .7550 .8624 .9298 .6749 .8948 .7171 .8314 .8303 .7909 .9818 1.0000

— 1 ¹²⁾ ) ¹²⁾ ) ¹²⁾ ) 12) ) ¹²⁾ ( ¹²⁾ ¹ ¹⁰⁾ ¹ ¹⁰⁾ ¹ ¹⁰⁾ 1 ¹⁰⁾ ¹ ¹²⁾ ¹ ¹²⁾

7” .000 7” .005 7” .000 7= .000 2= .016 9= .000 7= .020 9= .003 7 .003 7= .006 7 .000 7=

o Lf .3320 .4412 .3798 .1944 .2865 .2239 .3621 .2824 .2912 .2859 .6913 .7578

19) 1 19) 1 ¹⁹⁾ ¹ ¹⁹⁾ ¹ ¹⁹⁾ 1 ¹⁹⁾ ¹ ¹⁵⁾ ⁾ ¹⁵⁾ ¹ ¹⁵⁾ ¹ ¹⁷⁾ ¹ ¹⁴⁾ 1 ¹⁰⁾

7= .165 9= .059 7= .109 7= .425 6= .234 9= .357 7= .185 7= .308 ^P= .292 7” .266 2= .006 7= .011

0 080 .4673 .5521 .5180 .5627 .5157 .5720 .6335 .7061 .7125 .6213 .8276 .9372

24) ) ²⁴⁾ ) 24) ) ²³⁾ ) ²³⁾ ) ²³⁾ ( ¹⁷⁾ ) ¹⁹⁾ ) ¹⁹⁾ ) ¹⁶⁾ 1 ¹⁵⁾ 1 ¹¹⁾

7= .021 7= .005 7= .010 7= .005 7= .012 P= .004 7= .006 7= .001 7= .001 7= .010 7” .000 2= .000

o MIN .2732 .4393 .3460 .0153 .5885 .3037 —.1285 .7667 .6727 .7686 .2236 .9293

12) ) ¹²⁾ ) ¹²⁾ ¹ ¹¹⁾ ¹ ¹¹⁾ ⁾ ¹¹⁾ ⁾ ^7.1 ⁶⁾¹⁸⁾ ⁾ ⁷⁾ ⁾ ⁶⁾

) 5)

7= .390 9= .153 7= .271 7= .964 7” .057 7” .364 7= .784 2= .025 7” .068 7= .043 7= .044 7” .022

0 MIN 0 —.1579 —.1038 —.1375 —.0950 .3225 .1065 —.2803 .0463 —.0209 .0998 .7464 .9452

14) ) ¹⁴⁾ ) ¹⁴⁾ 1 ²²⁾ ⁾ ¹²⁾ ¹ ¹²⁾ ⁽ ⁷⁾ ¹ ¹⁰⁾ ) ¹⁰⁾ ¹ ⁷⁾ ) ⁷⁾ ) 5)

7= .590 7= .724 P= .639 7” .769 7= .307 7” .742 2” 543 7= .899 7= .954 ?= 831 2” .054 2” .015

0 0 MIN —.0172 —.0148 —.0165 —.5907 —2206 —.5004 —.8075 —.3517 —.4843 —.6250 —.4212 .5828

—S ( 12) ) ¹²⁾ ( ¹²⁾ 1 ¹²⁾ ( ¹²⁾ 1 12) t ⁷⁾ t ⁷⁾ 1 ⁷⁾ 1 ⁷⁾ ( ⁶⁾ ) ⁵⁾

7= .958 7= .964 7= .959 7= .043 7= .491 7” .098 7= .028 7= .439 7= .271 7= .133 7= .406 7= .302

0 14 MI 0 —.2099 —.2254 —.2209 —.1859 .0292 —.0943 —.8300 —.3788 —.4967 —.6999 —.4292 .6029

— ) 13) ) ¹³⁾ ¹ ¹³⁾ ¹ ¹²⁾ ¹ ¹²⁾ ¹ ¹²⁾ ^t ⁷⁾ ⁾ ⁹⁾ ¹ ⁹⁾ ) ⁷⁾ ⁾ ⁷⁾ ⁾ ⁵⁾

7= .491 2= .459 7= .468 7= .563 7” .928 7” .771 2= .021 7”' 315 2” .174 7= .080 7= .337 7= .282

7)1 EN —.0179 —.1323 —.0660 .4665 .0896 .3425 .3932 .3288 .3724 .0195 .6427 —.4755

— ) ¹⁶⁾ ) ¹⁶⁾ ) 16) 1 ¹⁶⁾ ) ¹⁶⁾ ) 16) 1 6) ) ⁶⁾ t ⁶⁾ 1 ⁹⁾ ⁾ ⁷⁾ ⁽ ⁴⁾

7= .948 ‘ 9 .625 7= .808 7= .059 7= .742 9= .194 7” .441 7= .525 7= .467 7= .960 7= .120 7” .524

7)1 EW —.0034 —.0972 —.0433 .4422 .2246 .3917 .4007 —.2894 —.1749 —.4892 .0416 —.7979

— f ²³⁾ ) ²³⁾ ) ²³⁾ 1 21) 1 ²¹⁾ ) ²¹⁾ ¹ ⁸⁾ ) ¹²⁾ 1 ¹²⁾ 1 ⁸⁾ ) ⁹⁾ ) ⁵⁾

7= .988 7= .659 7= .844 7= .045 7= .328 7= .079 7= .325 7= .362 7= .587 7” 219 7= .915 7= .106

DISCOL —.1203 —.1368 —.1317 —.1385 —.2509 —.2147 —.2132 —.0652 —.0844 —.3456 —.4074 —.6456

21) ) ²¹⁾ ) ²¹⁾ ¹ ¹⁶⁾ ¹ ¹⁶⁾ 1 ¹⁶⁾ ¹ ¹²⁾ 1 ¹⁴⁾ ¹ ¹⁴⁾ ¹ ¹⁰⁾ ⁾ ⁸⁾ ) ⁴⁾

9= .603 2= .554 7= .569 7= .609 7= .349 7” .425 2= .506 7= .825 7= .774 7= .328 7= .316 7= .354

DEFOLI —.0447 —.0920 —.0678 —.0179 —.2474 —.1386 .5027 .3203 .3531 .2975 .5797 —0155

22) ) ²²⁾ ^t ²²⁾ ) ¹⁷⁾ ⁾ ¹⁷⁾ ) ¹⁷⁾ ¹ ¹³⁾ ¹ ¹⁵⁾ ¹ ¹⁵⁾ 1 ¹⁰⁾ ¹ ⁹⁾ ) ⁵⁾

7= .843 7= .684 7” .764 2= .946 7= .338 7= .596 7= .080 7= .244 7= .197 7= .404 2= .102 7= .979

The Finnish Envoonmeot 27

N LF N 080 C MIN C MIN 0 0 N MIN C N MI 1 PM EN EN EN DISC0L DEFOLI

NH4N 0 17320 17673 2732 —17577 —:0172 -17009 —.0179 —.0034 —.1203 —.0447

— 9=( .16519) 7=f 24)021 9=) .39012) 9=) .59014) 7= .95812) 7= .49113) 7=) 19)948 7=( .92823) 7=t .603²¹⁾ 7=) .84322)

NO3N 0 4412 .5521 .4393 —.1038 —.0148 —.2254 —.1323 —.0972 —.1368 —.0920

— 7=t .05919) 7=t .00524) 9=) .15312) 7=t .72414) 7=t .96412) 7=) .45913) 9= .62516) 7=) .65923) 7=) .55421) 9=) 68422)

NT0T 0 .3798 .5180 3460 —.1375 —.0165 —.2209 —0660 —.0433 —.1317 —.0678

— ₇₌t _.10919) ₇) _.01024) ₇₌) _.27112) _P( _.63914) _P( _.95912) ) ¹³⁾ ) 15) ) 23) ) 21) ( 22) EN .468 7= .808 9= .844 7= .569 7 .764

NH4N T .1944 .5627 .0153 —.0950 -.5907 —.1859 .4565 .4422 -.1385 —.0179

— ₇₌) _.42519) ₉₌t _.00523) ₇₌) _.96411) ₇₌( _.76912) ) 12) ( 12) ) 16) ) 21) ) 16) ) 17)

NH4N 0 .3621 .6335 —.1285 —.2803 —.8075 —.8300 .3932 .4007 —.2132 .5027

— ₉₌t _.18515) ₇₌( _.00617) ₇₌C _.7847) ₇₌) _.5437) ₇₌t _.0287) ) 7) ) 5) ) 8) ) 12) ( 13) 7= .021 7= .441 EN .325 9= .506 EN .080 NO3N 0 7=.2824.30815) 7=( .7061.00119) 7=) .7667.0268) 7=) .0463.89910) 7=t—.3517.4397) 7=)—.3788.3159) 7=.3288525s) 9=—.2894.36212) 7=)—.0652.82514) 7=t .3203.24415)

NT0I 0 .2912 .7125 .6727 —.0209 —.4843 —.4967 .3724 —.1749 —.0844 .3531

— ₉₌) _.29215) ₇₌( _.00119) _EN) _.0688) ₇₌) _.95410) ) 7) ) 9) ) 6) ) 12) ( 14) ) 15) EN .271 7= .174 7= .467 7= .587 7= .774 EN .197 NF LF _EN.2859_.26617) _EN) .6213_.01016) _ENt .7686_.0437) _EN) .0998_.8317) )—.62507) )—.69997) ) .01959) )—.4892⁸⁾ )—.345610) ) .297510) 7= .133 EN .080 7= .960 7= .219 7= .328 7= .404

NEED 0 .6913 .8276 .8236 .7464 —.4212 —.4292 .6427 .0415 —.4074 .5797

— ₇₌) _.00614) ₇₌) .00015) 7=) .0446) 7=( .0547) 7=) .4066) 7=) .3377) 7=) .1207) 7=) .9159) 7=) .3168) 7=) .1029)

NEEN F .7578 .9372 .9293 .9452 .5828 .6029 —4755 —7979 —.6456 —.0165

— _EN) _.011¹⁰⁾ ₇₌) _.00011) _7’.) _.0225) ₇₌) _.0155) ₇₌) 5) ) 5) ) 4) ( 5) ) 4) ) 5) .302 7= .282 7= 524 7= .106 7= .354 7= .979

N LF 1,0000 .4526 .7126 .1492 —.3771 —.4243 —.0095 —.3078 —.1822 .5597

— _EN) .20) 7=) .05918) EN) .0478) EN) .7248) EN) .3578) EN) .2958) EN) .9819) EN) .35711) 7=) .57112) 7=) .05812) N 080 .4526 1.0000 .6304 .0181 —.5189 —.4875 —.3321 —.2738 .5653 .1909

— ₇) _.05918) ₇) _.26) ₇₌) _.03811) ₇₌) _.95313) ₇₌( _.10211) ) 13) ) 12) ) 17) ) 11) ) 11) 7= .091 7= .292 7= .288 7= .070 7= .574

0 MIN .7126 .6304 1.0000 .7784 .0202 .0501 .0493 —.6691 .0569 —.0240

— ₉₌) _.0478) ₇₌) _.03811) ₇₌) 12) ( 12) ) 11) ( 11) ) 10) ) ¹¹⁾ ) 7) ) 7)

. 7= .003 7= .953 EN .884 7 .892 EN .024 7= .904 7= .959

0 MIN 0 .1492 .0181 .7784 1,0000 —.0362 .4539 —.2352 —.4071 —.0727 —.3624

— ₇₌) _.7248) ₇₌) _.95313) _EN) _.00312) _EN) 14) ) 11) ) 13) ) 10) ( 13) ) 8) ) 8)

. 7= .916 7= .119 7= .513 7= .167 EN .864 7 .378

0 N MIN -.3771 —.5189 .0202 —.0362 1,0000 .9964 —.6631 —.7196 —.3693 .2870

—— ₇₌) _.3578) ) 11) ) 11) ) 11) ( 12) ) Iii ( 11) ) 11) ) 7) ) 7)

7= .102 7= ,953 7= .916 7= . EN .000 7= .026 EN .013 EN .415 EN .533

o N MI 0 —.4243 —.4875 .0501 .4539 .9964 1.0000 —.2446 —.4474 .0738 .0610

— 7=) .2958) 7=) .091¹³⁾ 7=) .88411) 7=) .11913) ENt .00011) ENt .13) 7=) 10)496 7=) .14512) 9=) .8628) 7=) .8858)

7)1 EN —.0095 —.3321 .0493 —.2352 —.6631 -.2446 1,000-0 .7319 .2729 —.2349

— ₇₌ _.9819) ₇₌) _.29212) ₇₌f _.89210) ₇₌) _.51310) ) 11) ) 10) ) 18) ) 17) ) 12) ) 12)

7= .026 EN .495 p= , 7= .001 7= .391 7= .462

7)1 EN -.3078 —.2738 —.6691 —.4071 —.7196 —.4474 .7319 1,0000 —.5508 —.1604

11) ) 17) ) 11) ) 13) ) 11) ) 12) ) 17) ( 25) t 15) ) 15)

7= .357 7= .288 9= .024 7= .167 7= .013 7= .145 7= .001 7= , 7= .033 7= .568

018001 ₇₌—.1822_.57112) ₇₌) .5653_.07011) ₇₌) .0569_.9047) )-.07278) t—.36937) ) .07388) ( .272912) t-.550815) )1,000022) )-.250422)

7= .864 7= .415 EN .862 7= .391 EN .033 7= , EN .261

EF0LI _9’..5597.05312) 7=) .1909.57411) 7—)—.0240.9597) 9=)—.3624.3788) EN( .2870.5337) EN) .06108868) 7—)—.2349.46212) 9=)—.1604.56815) EN—.2504.26122) EN(1.000023)

(Coefficient 7 )Cases) / 2-tailed Sig.ifioance) is printed if a coeffiient cannot be coputed

The Rnneh Enveonment 27

0

As indicated above, a major probiem regarding the IM database at present is the large amount of missing data. There is a large number of variabies of potential importance for evaluating nitrogen processes (e.g. soil carbon pools and pH, discoloration and defoliation of frees), but the number of sites with a fuil coverage of key variabies is quite limited. Therefore an improvement of the data collection and reporting should be another key topic for the IM workprogramme 96/97.

3.4 Conclusions

Acritical deposition threshold of about 8-3.0 kg N/ha/a is generally indicated by the input-output budgets in thisstudy, as well as several other previous assessments. It should, however, be recognized that these systems are not necessarily in a steady-state, and even low-deposition sites may eventually become saturated unless nitrogen is removed from the system.

- The output flux of nitrogen is strongly correlated wiffi key ecosystem variabies like N-deposition, N-concentration in organic matter and current year needies, and N-flux in litterfall.

- There is a great potential for using such statistical relationships from intensively studied sites in conjugation with regional monitoring data (e.g. ICP Forests and ICP Waters data) in order to 1mk process level data with regional-scale questions.

- A continuous effort should be devoted to improve collection and reporting of data in the ICP IM framework, in order to increase the number of sites with sufficient data for detailed effects assessments.

References

Aber, J.D., Nadelhoffer, Kj., Steudier, P. and Melillo, JM. 1989. Bio-Science 39, 378.

Allison, G.B. and Hughes, M.V. 1983.1. Hydrol.,60, 157.

Gundersen, P 1995a. Impacts of Nitrogen Deposition: Scientific Background. ICP IM Annual Synoptic Report 1995. ICP IM Programme Centre, Finnish Environment Agency, Helsinki, pp. 9-18.

Gundersen, P. 1995b. Nitrogen Cycling in European forests. In: Forsius, M and Kleemola, 5.

(eds.). Effects of Nitrogen Deposition on Integrated Monitoring Sites, Proceedings frorn an international workshop in Oslo, 6-7 March 1995, ICP IM Programme Centre, Finnish Environment Agenc3 Helsinki.

Dettinger, M.D. 1989. J.Hydrol.,106, 55.

Dise, N. and Wright, R.f. 1995. For. Ecol. Manage. 71, 153.

Lepistö, A., Andersson, L., Arheimer, B. & Sundblad, K. 1995. Water, Air and Soil Pollution 84, 81.

Sharma, M.L. and Hughes, M.V. 1985.J. Hydrol.,81, 93.

Spranger, T and Hollwurtel, E. 1994. Ecological Modelling 75/76, 257.

Stoddard,J. 1994. Long-Term Changes in Watershed Retention of Nitrogen^-Its Causes and Aquatic Consequences. In: Baker, A. (ed.). Environmental Chemistry of Lakes and Reservoirs, ACS Advances in Chemistry Series NO. 237. American Chemical Society, pp. 223-284.

Tietema, A. and Beier, C. 1995. For. Ecol. Manage. 71, 143.

Walker, G.R., Jolly, I.D. and Cook, P.G. 1991. J.Hydrol.,128, 49.

Wright, RE and Tietema, A. (eds.) 1995. For. Ecol. Manage. 71.

The

Finnish Environrnent 27

Evaluation ,f the EDACS model

In document 5th Annual Report 1996: UN ECE Convention on Long-Range Transboundary Air Pollution. International Co-operative Programme on Integrated Monitoring of Air Pollution Effects on Ecosystems (sivua 36-41)