Options for estimating horizontal visibility in hemiboreal forests using sparse airborne laser scanning data and forest inventory data

Figure 1

Figure 2

Model parameters (ALS) with RSE the model residual error and DF the number of indicated degrees of freedom_ The determination coefficient R2 for the nonlinear model (3) is an estimate_ Insignificant values (p > 0_05) are in italics_Tabel 2_ Mudelite parameetrid (lidarandmetest)_ RSE on mudeli jääkviga, DF on vabadusastmete arv_ Mittelineaarse mudeli (3) determinatsioonikordaja R2 kohta on antud hinnang_ Mitteolulised väärtused (p > 0_05) on kursiivis_

ModelMudel	DataAndmed	Parameters / Parameetrid
		a	b	c	d	RSE (m)	R2	DF
3	2017	2.59	0.023	−	−	28.3	*0.64	97
	2019	1.98	0.016	−	−	26.3	*0.69	97
4	2017	14.3	8.02	−	−	24.8	0.55	97
	2019	18.5	8.11	−	−	25.1	0.53	97
5	2017	4.59	6.08	0.362	−	23.9	0.59	96
	2019	2.72	5.26	0.506	−	23.8	0.59	96
6	2017	39.9	7.43	0.309	−0.610	21.8	0.66	95
	2019	28.4	7.73	0.438	−0.655	21.3	0.67	95

Description of the 70 sampling transects that were used for visibility prediction based on the forest inventory data_ G is basal area, H100 the site index_ A transect may extend over several forest stands_Tabel 1_ Takseertunnustele tuginevas nähtavuse simulatsioonkatses kasutatud vaatlustrasside kirjeldus neile jäävate eraldiste andmete põhjal_ G on rinnaspindala, H100 on kõrgusindeks_

Dominant speciesEnamuspuuliik	Age (yr)Vanus (a)	G (m2 ha−1)	H100 (m)	Count of standsPuistute arv
Pinus sylvestris L.	85 (23–158)	26 (2–45)	24 (10–34)	45
Betula pendula Roth, B. pubescens Ehrh.	49 (22–93)	20 (5–33)	28 (18–33)	28
Picea abies (L.) H. Karst.	60 (38–117)	24 (11–30)	30 (23–34)	15
Alnus glutinosa (L.) Gaertn.	58 (22–77)	22 (9–29)	27 (24–34)	5
Larix spp.	33	24	40	1
Alnus incana (L.) Moench	20	14	30	1