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Regional Environmental Changes: Application to Soil Erosion Modeling
1
INTRODUCTION
This paper presents some contributions to the silvicultural ecology domain, with
the aim of defining a methodology useful for determining an environmental
quality index. This index, obtained by a simple and quick survey procedure, is an
expression of the quality of the forest and is linked to the forest's ecological,
biological and physionomical characteristics. It is particularly useful, when, for
economic reasons, more accurate analyses cannot be performed.
The examined parameters represent characteristic qualities of the forest. A
synthetic numerical index was processed in order to determine the stability of the
forest by analyzing its structure.
2
METHODOLOGY AND RESULTS
Coniferous forests of the Western Alps (Piedmont Region) were analyzed during
the first research stage: particular attention was paid to Pinus sylvestris, Abies alba,
Picea excelsea and Larix decidua forests under different conditions.
Forty-five different sample areas were studied, in a random locality, each 600
square meters each. A total tree inventory was performed in the above mentioned
sample areas, by measuring all the trees with the following characteristics: a
minimum b.h. diameter of 5 cm , and a height not less than 2 m.
The thus determined structural complexity index determination was implemented
in four different steps:
determination of foliage height (reference height);
• tree component classification divided according to height;
analysis of the height distribution;
• determination of a numerical index evaluated by using a few parameters
(diameter distribution).
2.1 First step: determination of foliage height (reference
height)
The average height of the dominant layer was measured by calculating the average
value of the first six trees with the largest diameter. The obtained parameter, called
reference height (H2), is the comparison value used to determine the variability of
the tree height distribution in the sample area.
2.2 Second step: tree component classification divided
according to height
The space occupied by stems and crowns of every sample area was divided using
the highest tree height of the same sample: five different layers were obtained and
every tree was included in one of these layers. The determined layer thickness is
shown in Figure I.
Regional Environmental Changes: Application to Soil Erosion Modeling
1
INTRODUCTION
This paper presents some contributions to the silvicultural ecology domain, with
the aim of defining a methodology useful for determining an environmental
quality index. This index, obtained by a simple and quick survey procedure, is an
expression of the quality of the forest and is linked to the forest's ecological,
biological and physionomical characteristics. It is particularly useful, when, for
economic reasons, more accurate analyses cannot be performed.
The examined parameters represent characteristic qualities of the forest. A
synthetic numerical index was processed in order to determine the stability of the
forest by analyzing its structure.
2
METHODOLOGY AND RESULTS
Coniferous forests of the Western Alps (Piedmont Region) were analyzed during
the first research stage: particular attention was paid to Pinus sylvestris, Abies alba,
Picea excelsea and Larix decidua forests under different conditions.
Forty-five different sample areas were studied, in a random locality, each 600
square meters each. A total tree inventory was performed in the above mentioned
sample areas, by measuring all the trees with the following characteristics: a
minimum b.h. diameter of 5 cm , and a height not less than 2 m.
The thus determined structural complexity index determination was implemented
in four different steps:
determination of foliage height (reference height);
• tree component classification divided according to height;
analysis of the height distribution;
• determination of a numerical index evaluated by using a few parameters
(diameter distribution).
2.1 First step: determination of foliage height (reference
height)
The average height of the dominant layer was measured by calculating the average
value of the first six trees with the largest diameter. The obtained parameter, called
reference height (H2), is the comparison value used to determine the variability of
the tree height distribution in the sample area.
2.2 Second step: tree component classification divided
according to height
The space occupied by stems and crowns of every sample area was divided using
the highest tree height of the same sample: five different layers were obtained and
every tree was included in one of these layers. The determined layer thickness is
shown in Figure I.