| With the increasing attention on environmental protection and the strong demand for forest tourism,the plantation forests were gradually shifting from single timber production to multi-function including timber production,ecological protection,sightseeing and other functions,and from passive utilization to active operation.The visual resource became one of the most important resource of plantation forests,and the evaluation and management of plantation forests visual resources had been a significant research topic.Taking Saihanba Forest Plantation as an example and using the experience of research and practice of home and abroad,the questionnaires were used to investigate the visitors' demographic characteristics,motivation,visiting behavior and their effects on preference of plantation forests visual landscape,which were the basis of evaluation and management of plantation forests visual resource at different scales.At the landscape scale,a quantitative,accurate,and visualized assessment of the visual sensitivity of plantation forest landscapes was conducted using 9 map-based criteria(residential areas,recreation areas,roads,VU(Vegetation Unity)or CD(Colour Diversity),terrain diversity,edge presence,location significance,distance and visibility)based on 3 aspects,including amount and attention of users,landscape attractiveness and viewing condition,using the GIS-based multi-criteria evaluation(MCE)methods.At the stand scale,scenic beauty of 4 typical forest stands were studied in Saihanba including Larix principis rupprechtii pure plantation,Larix principis rupprechtii and Betula platyphylla mixed plantation,Pinus sylvestris var.mongholica lit.pure plantation and Betula platyphylla natural secondary forest;43 plots were set and Scenic Beauty Estimation(SBE)method was used to investigate the scenic beauty;Quantitative theory I model was used to build the regression model between scenic beauty and stand indexes.Using the result of evaluation of forest visual resources at landscape and stand scale,and taking Seven stars lake as an example,the viewshed method was proposed to determine the boundary and zoning of multi-functional areas,and the forest management strategies of different sub-areas were proposed;in the visible midground and visible background,Photoshop software was used to simulation analysis and restoration on landscape;In the visible foreground,the forest transformation strategy was proposed for the purpose to enrich visitors' experience.The main results were as follows:(1)Study on vistors' motivation and preference on forest visual landscapeThere was a significant difference between visitors' preference in 4 types of natural landscape,which were followed by grassland(4.33),forest(4.19),wetland(4.17)and lake(4.11).About human landscape,the evaluation value of the windmill landscape was higher(4.20),and the evaluation value of Saihan town(3.54)was lowest among all pictures.There was a significant difference between summer and autumn on preference of out-forest landscape on mixed forest,4.72 in autumn and 4.05 in summer.At the same time,there was also a significant difference between mixed forests and pure forests on preference of summer out-forest landscape,pure forest was 4.23 and mixed forest was 4.05.There were significant differences among 4 types of in-forest landscape,which were followed by Larix principis-rupprechtii pure plantation(4.31),natural secondary forest with a road(4.23),Pinus sylvestris var.mongholica lit.pure plantation(4.14)and Betula platyphylla natural secondary forest(4.09).According to the motivation,the tourists were divided into 5 categories,5 categories of tourists had a significant difference in the preference on forest landscape,meadow landscape,small town landscape,valley summer landscape,Larix principis-rupprechtii in-forest landscape,Pinus sylvestris var.mongholica lit.in-forest landscape,natural secondary forest landscape,Betula platyphylla secondary in-forest landscape,mixed out-forest summer landscape and windmill landscape(p<0.05).(2)Plantation forests visual landscape assessmentThis study proposed a forest management unit-based comprehensive assessment method for the visual sensitivity of a plantation forest landscape,and the assessment model was reliable.Landscape attractiveness was higest(0.51)among the main criteria,and the two others were almost equal.The vegetation was highest(0.23)and the residential area was lowest(0.04)among the sub-criteria.Three indices(i.e.,area(AREA),fractal dimension index(FRAC),and proximity(PROX)),were selected to construct the VU(vegetation uniformity)or CD(color diversity)index,which reflected the visual landscape in summer and autumn.The visual sensitivity maps showed that under the threshold of ?+2?,areas with high sensitivity were primarily concentrated in scenic areas and along both sides of the recreational roads.The mean value of visual sensitivity in summer was 33.5,with a standard deviation of 9.6,and that in autumn was 55.2,with a standard deviation of 7.5.Summer and autumn significantly differed in visual sensitivity( <0.01).(3)Scenic beauty evaluation of plantation forestsThe results showed that SBE score of Larix principis rupprechtii pure plantation(6.9),Larix principis rupprechtii pure forest and Betula platyphylla mixed plantation were higher(5.9),followed by Pinus sylvestris var.mongholica Litv.pure forest(-8.0),and Betula platyphylla natural secondary forest(-31.3)was the lowest.The SBE score was related significantly with average DBH,density,perspective distance,vertical structure,shrub average height,shrub layer coverage,and there was no significant correlation between SBE score with the biodiversity of shrub layer(p<0.05).The difference of SBE scores of the forest stands between with an average DBH of 15 cm or less,and the average DBH of 15?20 cm,>20 cm were significant,the former was the lowest(-33.1).The SBE scores of forests stands with a density of more than 1250 plants/ha and the other two density forests(less than 750 plants/ha,750?1250 plants/ha)were significantly different,and the former was the lowest(-25.8).There was a significant difference between the SBE scores of perspective distance of the 1 times tree height and the other two perspective distances(2 times the tree height and several times the tree height),and the former was the lowest(-18.7).The SBE scores of the tree-shrub structure and the tree-shrub-grass structure were significantly different,and the latter was lower(-22.1).The SBE scores of the forests stands with a coverage of >90% was significantly different from that of the forest with 0 and < 30%,and fomer was the lowest(-40.7).The SBE scores of the forests stands with the height 1?1.5m of shrub layer was significantly different from that of the height 0,<0.5m and 0.5?1m,and fomer was the lowest(-24.8).3 indicators of density,stand structure(with tree,shrub and grass),shrub layer coverage(more than 90%)entered the regression model,and had a negative correlation with SBE.(4)Study on management of visual landscape of multi-funtional areaThe Seven stars lake was divides to 3 functional aread: ecological protection area,visiual management area and forest harvesting area.And the visiual management area including 4 zones which were visible immediate foreground,visible foreground,visible midground,visible background.The area of visible immediate foreground and visible foreground of seven stars were small,accounting for 17%;However,the visible area of these two accounted for a higher proportion of the total area respectively,which the visible immediate foreground area accounted for 96% of the total area of the immediate foreground area,and the visible foreground area accounted for 41% of the total area of the foreground area.The area of visible midground and visible background accounted for a higher proportion of the total visible area,which was 83%,but scattered.In the visible immediate foreground and visible foreground,the forests were divided into the division for picnic and rest,the division for recreation for children and outdoor exhibition,the division for ecological experience and the division for scenic forest. |
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