Defoliation is assessed as the percent defoliation of a tree in comparison to a reference tree of same species and age growing at the same site with maximum foliage, the percentage of this defoliation that cannot be attributed to a known cause, the part of tree crown with above average defoliation, the percentage of defoliated branches and twigs and their location in the tree crown.The Sanasilva Inventory focusses on three groups of indicators for tree condition: Main indicators assessed in the Sanasilva Inventory During the inventory on the LWF long-term research sites, 10 percent of the plots are assessed by a second team as part of a consistency check.
#ETERNAL LANDS BOTS INVENTORY SOFTWARE#
Data are collected using tablet pc's and a data entry software called " Field-Map". Responsibilities are switched from plot to plot. One is responsible for the tree assessment and the other for the data entry. Each inventory crew consists of two persons. The field assessment is carried out in July and August. An identical satellite plot has been established 30 m due North of each plot. All trees with a diameter at breast height of at least 12 cm in the inner circle and with a minimum breast height diameter of 36 cm in the outer circle will be assessed. The outer circle has a radius of 12.62 m (500 m 2) and the inner circle has a radius of 7.98 m (200 m 2). The 16x16 subgrid is part of the European Level-I monitoring that covers 6,000 plots in 42 countries.Įach plot consists of two circles with identical center. This number has remained unchanged since then.
In 1995, 19 approximately 1,100 trees on a 16x16 km subgrid were assessed. In 1993, 19 approximately 4,000 trees were assessed on a 8x8 km subgrid. From 1985 until 1992 we assessed approximately 8,000 trees on nearly 700 plots placed on a 4x4 km grid.
The size of the systematic sample grid has been reduced over the years.
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