Site form classification—a practical tool for guiding site-specific tropical forest landscape restoration and management

Abstract

Reliable estimates of forest productivity at the site scale can guide site-specific forest management. However, the best methods to evaluate productivity of natural forest sites, and in particular secondary natural forests, remain undefined. In this study we: (1) applied an indirect method for estimation of the potential productivity of a forest site (‘site form’) in Dong Nai Biosphere Reserve. In addition, we: (2a) investigated the influence of a range of environmental conditions on site form, (2b) built models to estimate site form from the corresponding environmental variables and (3) generated site form maps for the region. We found that Michaelis–Menten models provided the most consistent representation of tree height–diameter relationships, with reliable anamorphic curves at both plot-scale (50 m × 20 m) and multiplot-scales. Predicted tree height at 25-cm diameter (H25) was selected as the best indicator for site form as 25 cm was both a tree size, which was common in the forests, and for which height could be accurately predicted. H25 was significantly correlated with site environmental conditions, with the dominant influences being factors related to water availability. We generated site form maps for Dong Nai province based on the relationship between known environmental variables and H25. We conclude that maps such as these could have broad application in guiding tropical forest restoration measures elsewhere, particularly where there is limited knowledge of tree ages and species.

The Choice of a Set of Operations for Forest Landscape Restoration Technology

“…Analysis of the dendrogram based on Ward's method (Figure 6) shows the following pronounced clusters in the upper part of the dendrogram I (1-4, 6, 8, 13, 14, 31), II (9,17,18,20,21,23,25), III (11,12,10), and IV (19,22,24), and a large number of clusters in the lower part of the dendrogram. There are differences between them, but they are insignificant.…”

“…Therefore, it is necessary to decompose the algorithm into six blocks, each of which can be calculated mathematically and, having the final results, combined into a single technological pipeline. Analysis of the dendrogram based on Ward's method (Figure 6) shows the following pronounced clusters in the upper part of the dendrogram I (1-4, 6, 8, 13, 14, 31), II (9,17,18,20,21,23,25), III (11,12,10), and IV (19,22,24), and a large number of clusters in the lower part of the dendrogram. There are differences between them, but they are insignificant.…”

“…Modern technological studies of the implementation of the FLR approach are presented, in general, as strategic issues' articles (for example, [17]), research papers (for example, [18][19][20]), and reviews (for example, [21]). The presented papers do not contain mathematical justification and optimization of mathematical models aimed at the selection and consistency of a set of technological operations and technical means in FLR technology.…”

Evaluation of the Site Form as a Site Productive Indicator in Temperate Uneven-Aged Multispecies Forests in Durango, Mexico

“…It has been successfully used as an indicator of productivity in uneven-aged stands [ 12 ] and has delivered meaningful results in even-aged forests [ 13 ]. Nonetheless, the main feature of SF is its capacity to describe site quality in uneven-aged multispecies forests [ 14 ].…”

“…The assessment of the usefulness of the SF as a measure of productivity has been carried out through different methods. For instance, the SF as the average H at a specific reference D (SF H-D ) [ 10 ], as the expected mean H (MH) at a reference mean D (MD) (SF MH-MD ) [ 12 , 13 ], and as the tree height (h) at a reference diameter at breast height (dbh) estimated using a specific h-dbh model for a given site plot (SF h-dbh ) [ 14 ]. Nevertheless, there is no documentation about their comparison, and the results therefore may vary despite being based on the same assumption.…”