DIGITALNA ARHIVA ŠUMARSKOG LISTA
prilagođeno pretraživanje po punom tekstu
ŠUMARSKI LIST 1-2/2011 str. 24 <-- 24 --> PDF |
M. Kobal, M. Urbančič, N. Potočić, B. De Vos, P. Simončič: PEDOTRANSFER FUNCTIONS FOR BULK DENSITY ... Šumarski list br. 1–2, CXXXV (2011), 19-27 22 Statistical analyses were carried out using the R 2.9.3 software environment (R Development Core Team, 2009). Package ‘’segmented’’was used to fitre- gression models with segmented relationships(Mug- geo,2008). 3 RESULTS AND DISCUSSION – Rezultati i rasprava 3.1 Development of local PTF for predicting soil bulk density of mineral part of soil Razvoj lokalnih pedotransfer funkcija za predviđanje gustoće mineralnog sloja tla Soil bulk densityand concentration of organic car- bon were strongly correlated (r = -0.86, p < 0.001). Other chemical soil properties, except the concentra- tion of total nitrogen (N), were less correlated with bulk density (Figure 3).The correlation between bulk density and base saturation (BS) and the correlation between bulk density and clay content were not statisti- cally significant (p > 0.05). Figure 3 Relationship between bulk density (.b) and concentration of organic carbon (OC), concentration of total nitrogen (N), cation exchange capacity (CEC), base saturation (BS) and clay content (Clay) for 106 soil samples. Slika 3. Odnos gustoće tla i koncentracije organskog ugljika (OC), ukupnog dušika (N), pH, kapaciteta za izmjenu kationa (KIK), sume baza (BS) i sadržaja gline (glina) za 106 uzoraka. More than 73 % of the total variability of bulk den- sity was explained byOC (model SFI 1,Table 2).Ad- ding other chemical properties as explanatory variables in the multiple regression models(modelsSFI 2, SFI 3, Table 2 Regression relationship between soil properties as predictors and bulk density as response for 106 soil horizons (OC – organic carbon, BS – base saturation, CEC – cation exchange capacity, CLAY- clay content. Tablica 2.Regresijski odnos karakteristika tla kao prediktora i gustoće tla kao odziva za 106 horizonata tla (OC – organski ugljik, BS – suma baza, KIK - kapacitet za izmjenu kationa, glina – sadržaj gline). Model Response variable Intercept OC pH* BS* CEC* CLAY* SE Adj. R 2 Varijabla odziva KIK glina SFI 1 .b 1.3983 -0.0734 0.1403 0.7384 SFI 2 .b 1.4509 -0.0720 -0.0115 0.1404 0.7379 SFI 3 .b 1.3752 -0.0749 0.0004 0.1399 0.7398 SFI 4 .b 1.3902 -0.0788 -0.0011 0.1402 0.7385 SFI 5 .b 1.3438 -0.0734 0.0019 0.1390 0.7431 SFI 6 .b for OC < 3.6 % 1.4842 -0.1424 0.1257 0.7958.b for OC . 3.6 % 1.1253 -0.0452 * denotes not statistically significant variable in the model * označava nesignifikantnost varijable u modelu Bulk density/gustoća tla [g/m3 ] Bulk density/gustoća tla [g/m3 ] Bulk density/gustoća tla [g/m3 ] Bulk density/gustoća tla [g/m3 ] Bulk density/gustoća tla [g/m3 ] Bulk density/gustoća tla [g/m3 ] |