Gregory A. Isachenko
Landscape - dynamical studies in North - Western Russia: basic results and
environmental applications
Landscape science as the independent direction in physical geography has arisen on a
boundary of XIX and XX c, when in natural - science disciplines integration tendencies have
amplified. In the landscape doctrine in the most concentrated way the ideas about general connection
of components and elements of a nature, necessity of geographical synthesis at qualitatively new level
were focused.
Almost simultaneous occurrence and development of landscape ideas in Russia, Germany,
France and other countries does not allow to speak about landscape science as about a national
scientific phenomenon. At the same time weak «rooting» of the landscape doctrine in the majority of
the Anglo - Saxon countries, and also in Scandinavia points to deep connections of occurrence of the
given scientific discipline with ethnic - cultural environment, traditions of scientific thinking, and,
undoubtedly, with geographical features of the appropriate countries.
Most actively landscape science in the USSR and the countries of the Central Europe
developed after the Second world war. In 1950 − 1960s the hierarchy of natural territorial complexes
(geocomplexes) was in details investigated and concepts of morphological structure of a landscape and
its units which have received different names in the different countries (in Russian terminology fatsia, ourochishche, mestnost etc.) were issued. At that time theoretical concepts, long years
dominated in a science and becoming its "dogmata", have been formulated: for example, ideas of
school of the Moscow university (under N.A. Solntsev leadership) about the leading role of
«lithogenic base» in landscapes.
The basic result of an "extensive" stage of landscape science development was accumulation
of an large empirical material about principles of spatial differentiation of the Earth in different scales.
It is possible, not exaggerating to tell, that research of a phenomenon of the hierarchical organization
of space in macrocosm began the major contribution of landscape research in global natural sciences.
Various models of hierarchical systems of landscapes (schemes of physical - geographic
regionalization) always bear a print of geographical features of those regions where researchers work.
So, in the countries of the former USSR exists up to ten schools of landscape studies with various
principles of regionalization and typology of landscapes and even a terminology. The same can be told
about development of landscape researches in the countries of the Central Europe. The basic
achievements of the landscape science in the countries of East and Central Europe (the countries of the
CIS, Baltic states, Poland, East Germany, Czechia, Slovakia, Bulgaria) are connected to wide
introduction of the complex (system) approach in physical - geographic researches, development of
principles and methods of multi - scale landscape mapping, development of applied landscape
researches for the purposes of regional planning and rational environmental management.
Landscape mapping can be regarded as the universal and most effective tool of the description
(modelling) of heterogeneity of space on the macro - level. It assumes drawing of borders between
geocomplexes − that is «discretization» of the territory. This procedure is inevitable at any research of
the spatial structure of territory. But landscape maps of «the first generation» did not reflect mobility
of hierarchy of geocomplexes. The drawn borders, as well as the marked geocomplexes of different
spatial rank, were quite often examined as «most objective» spatial units where all components are
rigidly connected. Traditional concepts of morphology («statics») of a landscape have conflicted to the
new data concerned different frequency of various components and elements of a landscape,
probabilistic character of their connection, existing of different landscape structures. Studies of
functioning and dynamics of the geocomplexes, carried out basically on physical - geographic field
stations, have been alternative of morphology of a landscape of a sort. The network of such field
stations was created in the USSR and the countries of the Central Europe in 1970 – 1980s.
Landscape-dynamical studies in North – Western Russia: basic results and environmental applications
43
At the end of XX c the necessity of synthesis of «static» and «functional - dynamic»
components of landscape science was clearly realized. Such works have appeared in the different
centers of a landscape science and in many respects were initiated by development of applied
applications of landscape approach − landscape planning and design, environmental assessment and
resource evaluation, ecological examination.
The author belongs to Leningrad - Petersburg school of landscape researches which traditions
ascend to the works of V.V. Dokuchaev and L.S. Berg. The basic region of researches of scientists of
this school traditionally have been the North and North - West of the European Russia, within the
limits of zones of a taiga and hemi - boreal forest (sub - taiga). The author and his colleagues from
Laboratory of Landscape Research and Ecological Mapping (Research Institute of Geography,
University of St. Petersburg) since 1990 have carried out field researches of landscapes in the
Leningrad, Pskov oblast (districts) and Republic of Karelia. Since 1992 stationary observations on 25
experimental plots in North - West Ladoga region (150 km to the north from St.- Petersburg) have
been carried out as well.
On the basis of results of 15 - years researches the concept of the landscape - dynamic analysis
was developed. The main substantive principles can be formulated as follows:
1. In each landscape (or geocomplex, natural - territorial complex) different components and elements
have different characteristic time (time of full change of object or time of one full cycle at cyclic
character of changes).
2. Depending on characteristic time, in any elementary landscape (geocomplex) the stable part, or a
site, and a dynamical part which is described by a set of states of different duration (from diurnal up to
long - term ones) are recognized. The site is described by the basic elements - the form of a relief and
the upper layer of pedogen (soil - forming) bedrock. It was established based on a wealth of evidence
that the basic morphological features of a relief and the characteristics of the upper layer of bedrocks
in identical climatic conditions and at absence of human impact unequivocally cause character and a
degree of moistening regime (or conditions of natural drainage) of sites and a mode of migration of
substance.
Characteristics of states (concerning basically to vegetation and some soil properties) change 1 - 3
orders more slowly, than attributes of sites.
When mapping borders of geocomplexes are drawn first of all as a borders of sites. These
borders are not absolute but only mark out position of strips of the greatest territorial contrasts. In
other words, the characteristics of environment vary more strongly between sites, than within the
limits of sites (= geocomplexes).
3. Dynamics of a geocomplex is understood as set of all of its states of different duration, and also set
of transitions between states. Transitions which have the certain duration, also can be examined as
states (using larger time scale). For example, in continental areas of a taiga duration of spring and
autumn seasons is shorter in comparison with duration of the basic (winter and (summer) seasons.
Therefore first two seasons can be considered as transitions between two last states.
It is possible to speak about short-, middle - and long - term dynamics of geocomplexes
(correspondingly duration less than 1 year, from 1 year till 10 years, tens and first hundreds years).
4. Irreversible changes of a relief and substratum (upper layer of pedogen bedrock) under impact of
processes with characteristic time, as a rule, more than 1000 years are considered as evolution of
geocomplexes.
Let's note, that geocomplexes of a local level can stop the existence and pass in other
geocomplexes as a result of fast catastrophic processes (earthquakes, landslides etc) or strong
technogenic impacts (e.g. open mining).
5. Processes in landscapes and its components have different causality. One processes have
spontaneous character, i.e. occur without any human participation, and sometimes without an
opportunity of such participation.
Spontaneous processes can be caused by exogenic (bogging under influence of climate
changes) or endogenic factors (bogging due to neo - tectonic lowering of territory). Some processes
are determined by self - development of separate natural bodies: for example, overgrowing of the
surfaces which have left from under water. The majority of spontaneous processes in a nature is
caused by simultaneous action of several external factors.
44
Gregory A. Isachenko
Other category of processes is connected to human activity, i.e. with various human impacts.
Impact is understood as the event caused by external (natural and/or anthropogenic) factors and
causing relatively fast change of a state of geocomplex. Three basic groups of impacts on
geocomplexes are divided: point - source, linear and areal impacts.
Anthropogenic influence can be short - term, representing itself as an initial push with
subsequent «start» of spontaneous processes (e.g. natural forest regeneration after clear cutting), or
long (ploughing up of the territory and its use for agriculture).
6. Character and intensity of human impacts on a landscape in each historical period are determined by
set of the economic, sociopolitical, ethnic factors realized in regional system of environmental
management. To study a modern condition and tendencies of change of any geocomplex, it is
necessary to analyze changes of landscapes at previous historical periods.
7. Concerning processes it is necessary to note two basic moments.
First, the superposition of different processes always takes place. So, forest regeneration on
cuttings is complicated and slowed down by periodic local fires, overgrowing by herbs, partial
bogging etc.
Second, processes of different causes can have similar character of manifestation in
landscapes. As an example we can mention forest fires which result in similar consequences
irrespective of the reason.
8. Each impact can be considered as a starting point of the subsequent dynamic trajectories of a
geocomplex. The trajectory represents a sequence of long - term states. We can not always indicate
with hundred – per - cent probability, in what direction the given geocomplex after any impact will
change. Differently, the number of possible trajectories of the given geocomplex as a result of any
impact (or during its realization) usually exceeds one.
The set of possible trajectories is the less, than connections in a landscape are more rigid and than
the set of species of plants and animals which can occupy the released (due to impact) ecological
niches is more limited. In a taiga of North - West of the European Russia the least variety of dynamic
trajectories is typical of geocomplexes of extreme sites − granite rocks and oligotrophic bogs.
9. Every superposition of the impacts complicates a dynamic trajectory of a geocomplex and brings in
it various «lateral branches». Our studies show, that the number of additional modifications forming at
such branches is not infinite as the amount of influencing factors in a nature exceeds the number of
possible reactions to impacts.
Any type of a landscape at any period of time is represented in territory by various stages and
modifications of one or several dynamic trajectories (e.g. different stages of coniferous forest
regeneration after different - time clearings and fires).
Hence, the key idea of landscape - dynamical analysis is dividing characteristics of elementary
landscapes into two categories: site characteristics and state characteristics. Sites are relatively stable
in time, states are «mobile» and change due to numerous impacts. Both sites and states can be
classified and typified.
Typology of sites in concrete landscape zones and provinces gives a basis for landscape
mapping. We have developed typology of sites for landscapes of a taiga of North - West of the
European Russia, including more than 50 kinds of sites. This typology is applied to landscape
mapping in large and average scales (1: 5000 − 1: 500 000).
Sites are designated by two or three letters of the latin alphabet; in a basis of indexes the first
letters of the English or latin terms lay. Examples of types of sites are:
Pf − wavy plains and terraces on sand and sandy loam without cobble, naturally drained, with
mineral soils
Lf − slightly - wavy and flat swampy plains on sand and sandy loam, covered by thin peat,
with organic - mineral soils
Landscape-dynamical studies in North – Western Russia: basic results and environmental applications
45
Bo − oligotrophic (raised) bogs with homogenous structure and hummocks; peat thickness, as
a rule, is more than 1,5 m
For tens and first hundreds years a moistening regime of sites, the top layer of soil - forming
rock, mechanical composition of soil can change owing to human impacts. Changes (due to impact)
even one characteristic from the basic attributes of a site for a while, comparable with characteristic
time of natural sites, also are reflected in typology of sites. It occurs, for example, as a result of long term drainage and cultivating bogs when the water level considerably falls, peat becomes more
mineral, the microrelief changes. In this case the site modifications are allocated, such as:
Pfk - wavy plains and terraces on sand and sandy loam without cobble, cultivated, with thick
humus horizon
Bod - oligotrophic (raised) bogs, artificially drained, with mineralized upper peat horizon
The classification of long - term states of geocomplexes takes into account such characteristics
as :
•
a role of vegetation (and produced phytomass) in formation of a vertical structure and lateral
structure of a geocomplex; according to this attribute «productive» states are divided from
«unproductive» (abiogenic) states – e.g. inside urban territories)
•
a development of processes of soil formation
•
dominance of various types of vegetation and, accordingly, a degree of manifestation of
environment - creation functions (wood, grassy vegetation and so forth).
•
spontaneity of development of vegetation or necessity of human control over it (for example,
agricultural crops)
In geocomplexes of a taiga zone of the European Russia long - term states with dominance of
tree phytomass prevail. These states are classified by the following criteria:
I. A stage of development of the forest stand, described by the tendency of change stand phytomass (or
growstock), vertical and horizontal structure. The following states are allocated:
1) Forming: fast increase of phytomass, increase of thickness of a vertical profile, change of lateral
structures with change of dominants of ground vegetation. This state is subdivided into stages by
duration no more than 20 - 25 years everyone: a stage of formation of a young growth layer (on fire
places, cuttings, former agricultural lands); a stage of transition of young growth in a forest stand with
intensive self - thinning; a stage of young forest with formation of a close forest stand.
2) Gradual accumulation of phytomass; relative stabilization of vertical and lateral structures
of a landscape; formation of several generations of trees; manifestation of tendencies of replacement
of one tree dominant by another (not always).
3) Reduction of tree phytomass; partial (in some cases complete) destruction of a stand of
dominant tree species with mass transition in a dead wood; quite often − strongly pronounced change
of dominant trees.
It is necessary to take into account, that age gradation of stages can differ for forests, formed
by different dominant tree species.
II. The tree species prevailing in a growstock (spruce, pine, birch, aspen, alder grey, alder black).
III. The tendency of change of a forest stand composition.
IV. The special attributes of states concerning, for example, to a biogenic microrelief.
As an example of long - term state of a geocomplex of drained plains on sand without cobble
we refer to stabilization in middle - age birch - aspen wood with activization of spruce.
Application of the listed above concepts in practice of landscape - dynamic researches is
realized through a complex of methods which can be grouped as follows:
46
Gregory A. Isachenko
1. Studying of processes in real time (stationary observations). The main principle of stationary
researches is, that frequency of observation of any process should correspond to own frequency of this
process, or characteristic time of change of a natural body. Application of this principle concerning
research of long - term processes in geocomplexes allows essentially to save forces and means and to
be limited to observations with frequency 3 - 4 times per one year, and sometimes even once a year.
Stationary investigations, as against routing researches, are concentrated on the fixed key areas
(plots) or other objects. Plots of observation are chosen so that they, on the one hand, would be
representative for the much greater territory, and on the other hand, would reflect specificity of the
given region. The received data should be extrapolated on the certain region or types of landscapes.
In 1992 Landscape - ecological Field Station (LEFS) was organized as a part of Department of
Geography and Geoecology and Research Institute of Geography, University of St. Petersburg. LEFS
is situated 150 km north from St. Petersburg, in the contact zone between Baltic crystalline shield and
East - European plain. The observations are made on 25 test plots with area from 1 to 2500 m2. The
plots have been chosen for studying natural (spontaneous) processes as well as changes caused by
human influence. The regional natural processes available for observation are: autogenic vegetation
successions (e.g. interaction spruce − pine in forests), overgrowing of granite rocks, interrelations
bog−forest, local bogging, overgrowing of lakes. The present human impacts on landscapes are:
clearings, forest fires, drainage, cessation of land cultivation, granite excavation, recreation.
2. Time interpretation of spatial combinations and rows. The idea of the method is, that the
conclusions about a sequence of states (stages of process) in time are made on the basis of studying
simultaneous distribution of observable states in space.
Studying of long - term processes − results of various impacts − is possible on spatially
separated contours of one type of geocomplexes. The assumption is accepted, that in one type of
geocomplexes to restore a consequences of the certain influence is possible on discrete areas with the
different dates of the given influence. For the decision of this problem dating the influences which
have «started» the process, is necessary.
Thus the processes after clear - cuts and fires in different types of sites were studied. The
given approach can be used for studying long - term consequences of clear and selective cuttings,
fires, artificial drainage − i.e. influences with well dated terms. As «reference mark» it is possible to
consider such dated events, as the cessation of long - term human influences: abandoning of meadows,
arable lands, destruction of dams and locks etc.
3. Research of continuous time rows (dendro - indication, the analysis of series of meteorological data
etc). For an estimation of regional changes of landscapes the most indicative are the rows of a radial
annual growth of coniferous trees, growing in extreme conditions for a taiga: rocky surfaces and
oligotrophic bogs. Annual rings of the trees growing in other types of sites, usually store the
information on local influences: fires, cuttings, bog and forest drainage.
4. The analysis of structure of forest stands of taiga woods. Within the limits of one wood plot, due to
presence of trees of different age, the information on the last states of the given geocomplex stores.
These data, proceeding from prevailing age of ripe forest stands of a southern taiga of North - West of
the European Russia, can cover the period up to 120 years.
For taiga landscapes the account of characteristics of populations of the basic tree species is
especially important. The analysis of structure of a forest stand is made on the data received of
continuous forest valuation of trees and young growth on the test plots with size from 2500 to 10000
m2. On each test plot separately for everyone tree species (spruce, pine, birch, aspen etc.) are made
distributions of trees on diameter and height. The received set of distributions is indicated as a
spectrum of a forest stand of a researched site.
The main part of the investigated taiga stands represents stages of regenerative successions after
felling and fires. It is visible on their rather small age and significant participation of deciduous trees.
As a first approximation the stage of a wood on a trajectory of regenerative succession can be
estimated using qualitative characteristics of tree composition: presence and regeneration of deciduous
trees, ratio of a pine and a spruce in a forest stand as a whole and in the first layer of the stand.
Landscape-dynamical studies in North – Western Russia: basic results and environmental applications
47
Besides the statistics calculated for each spectrum of a forest stand are used: factor of a variation (an
estimation of a degree of non - uniformity of a stand) and entropy of distribution (a measure of
structural complexity of a stand).
In quality of more thin criteria of dynamics of the stands describing the form of distribution of
trunks, factors of asymmetry S and excess E are used (Isachenko & Reznikov, 1996). They show, as
far as distribution is displaced to the left concerning the centre. With increase of age of each
generation of one tree species these both criteria for it should decrease. At calculation of statistical
criteria of distributions young growth is also taken into account.
Knowing structure of a researched forest stand and law of its change in time, it is possible to
determine approximately the past and the future of the given forest stand. Having arranged the tree
species participating in the given forest stand, on decrease of values of factor of asymmetry, we shall
receive a line of relative «dynamic activity» of tree species. If now one tree species is dominant in
growstock in a given stand, and another tree species prevails in «dynamic activity», it is possible to
assume the process of change of dominant trees in the given geocomplex.
5. The ecological - floristic analysis. In each description of the test plot the index of a «total thickness»
(combined abundance and projective cover degree) of the vascular plant species belonging to different
ecological - floristic groups (boreal forest herbs, nemoral forest herbs, mesohygrophytes etc.) are
counted up. The ratio of «total thickness» of species of certain ecological - floristic groups in
geocomplexes are examined as attributes of dynamic tendencies of landscapes. For example, at
progressing bogging (absolute and relative) «total thickness» of hygrophytes increases, and the «total
thickness» mesophytic and mesohygrophytic herbs decreases. The given method yields good results at
studying processes on desolated agricultural lands (see below)
5. Comparison of different - time maps and remote images. Traditional method of studying and
comparison of old maps has the big prospects in landscape - dynamic aspect. For the investigated
region suitable for landscape reconstruction cartographical materials are dated by XVII c. However
most frequently for comparative researches maps of later time are used, for example, Russian military
- topographical maps of XIX c. We shall note, that use of old maps for comparison with modern and
revealing of tendencies of change of landscapes is connected to a number of difficulties (smaller
information and accuracy of old maps, the difference in legends and other). For overlapping old maps
with a modern cartographical basis various methods are applied, including computer correction with
use of "rigid" points and lines (tops, cross - roads, marginal points of lakes).
Exclusive opportunities for the analysis of changes of landscapes are given with comparison
of aerial photographs (accessible from middle XX c), and space pictures for last decades.
The results of our studies allow to describe the main processes of long - term dynamics of
taiga landscapes of the North - Western Russia. In more detail it makes sense to examine spontaneous
changes of forest stands and processes on the abandoned agricultural lands.
Spontaneous changes of forest stands.
On the basis of the analysis of several hundreds spectra of a forest stand, and also a rows of a
radial annual growth of the trees for the basic types of sites the models of long - term dynamics of
woods were developed both during spontaneous development, and as a result of impacts (clear
cuttings, fires). It is revealed 7 basic processes of change of forest stands (pine −− spruce, aspen −−
spruce etc.) and their probability in different types of sites is determined.
It has been established that in the majority of sites the «final» state (that is after finishing of the
current process) is more determined by site conditions (sometimes with 100 % of probability), than
their present state. So, on broadly distributed in region drained plains on till spontaneous development
of forest stands should result in 100 % domination of spruce forests. However at destruction of a wood
in half of cases forest regeneration goes with change of tree species, including in a quarter of cases −
through the dominance of deciduous trees (birch, aspen). By this means, the observed diversity of tree
stands here is maintained due to different external impacts. If there are no human impacts among these
influences the arising spatial combination of forest stands can be named «a primary wood». In such
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Gregory A. Isachenko
wood the share of old - age stands will be more, than the woods, exposed to anthropogenic impacts,
but there will be also younger forest stands, fire and windfall places.
Generally the «final» forest state is that of spruce stand, so that the hypothesis of present spruce
advance (in the absence of impacts) is statistically verified. In certain sites where the pine stands are
more typical (cameo sandy hills, plains on fluvio - glacial sands) on the contrary, the «initial» state is
more determined; after that the uncertainty increases from the «current» to the «final» state.
Consequently, the stability of the stand composition here is provided by periodic external impacts,
predominantly by fires. Fire - prevention actions in such sites promote development of spruce stands.
So, on Karelian isthmus where sandy landscapes prevail, the share of pine forests in the total wood
area in the period 1948 − 1983 was reduced to 12 %, and the share of spruce woods has grown for
same time for 8 %.
The course of forest regeneration successions in many respects is determined also by the
neighbourhood of the cut (burned) areas of a wood with the non - disturbed sites as a sources of seeds
of this or that tree species. So, the spruce will not regenerate in landscape conditions suitable to it if
spruce groves in nearby area are completely absent in radius of ten kilometers. In a process of
approach of forest communities to final («climax») states in the same type of sites the ground
vegetation, as a rule, changes to the more poor floristic composition. In pine woods dominance passes
from a heather and lichens to green mosses; in spruce woods the process of increase of a canopy
density leads to the dominance of bilberry, green mosses and even sphagnous mosses. It is necessary
to note, that in different types of sites old - age coniferous woods (in particular spruce ones) have
significant similarity of ground vegetation composition as well.
In view of told above, concept of the primary vegetation (including primary wood
communities), being one of the most fundamental in Russian phytosociology, has substantially
conditional character. In the same site 1000 - year change of states which includes 400 years of pine
wood, 300 years of spruce wood 300 years of small - leaved wood, is possible. What state from this
sequence should be regarded as «primary»? Any of answers to this question will be conditional. Only
some («extreme») types of landscapes have one prevailing community, almost non - changed in time.
Forest regeneration and paludification on abandoned agricultural lands.
Since middle XX c in northern part of the European Russia under the influence of socio - economic
factors the great change of system of environmental management and land use have taken place. It can
be shown, in particular, in the termination of use of the agricultural lands on the area of thousand
square kilometers.
As a result of field data treatment, remote sensing analysis and different - time maps
comparison the processes of agricultural lands desolation were described as applied to most typical
taiga landscapes in the North - West of European Russia. The dynamics of abandoned meadows,
pastures and arable lands can be described by two main successions («trajectories»): 1) overgrowing
by forest, 2) sedge moor and bog regeneration (paludification). The first one is dominant. In the course
of the overgrowing succession we can distinguish four long - standing stages:
a) meadows with unclose young growth of small - leaved trees (grey alder, birch, asp, willow) and
willow - shrub (up to 3 m in height) - not longer than 15 years after cessation of use;
b) alternating close young deciduous groves (3-10 m in height) and patches of meadows with shrub
(up to 25 - 30 years after abandoning);
c) close stand (15 - 20 m in height, crown density is not less than 40 %) with domination of small leaved trees and, sometimes, with underbrush of conifers; the duration of this stage counts tens or even
one hundred years;
d) mixed boreal forest with progressive supplanting of deciduous trees by spruce (Picea abies),
evolving close to the typical boreal forest communities: the stage comes not earlier than 70 - 100 years
after the total abandoning of cultivated plot.
Natural regeneration of coniferous trees in forest stands, evolved on the abandoned meadows
and arable lands (that is approach of a stage d), occurs far from being always. It is connected to often
absence near to overgrowing agricultural lands the areas of coniferous woods − sources of seeds. In
result there is a constant growth of the area of small - leaved woods with prevalence of birch, aspen
and grey alder. Now the area of desolated agricultural lands makes in different regions of the North of
Landscape-dynamical studies in North – Western Russia: basic results and environmental applications
49
the European Russia from 40 up to 75 % of the area of the cultivated lands used in middle XX c.
Among other long - term changes of landscapes which are investigated with the help of the
methods described above: overgrowing of open rocky substrata; dynamics of the drained peat bogs
and places of peat excavation; changes of geocomplexes at the bottom of the lowered water bodies.
The most effective way of study, representation and simulation of spatial and spatial - temporal
aspects of the landscape changes and regional environmental situation is landscape - dynamical
mapping. The principal idea of this method is creation of map series based on the same pattern (grid)
of territorial units (landscapes, sites etc). The series of maps includes: basic landscape map, map of
impacts, map of present processes, landscape - dynamical scenarios maps etc.
The basic landscape map, or map of sites represents framework («skeleton») of all maps in the
series. It is created by the methods of field survey using remote sensing analysis. The taxonomical
rank of landscape units to be mapped is defined both by map scale and features of regional landscape
structure.
Map of impacts on landscapes is also created on evidence derived from field investigations.
Besides, the analysis of old maps, different - time aerial pictures, historical data is used. Impacts are
characterized by its age, intensity and results for different components and elements of landscape. The
fact is that for certain impacts (e.g. forest fires) it is practically impossible to establish the cause, while
the fires both of human and natural cause have the same consequences for landscape. Every type of
impact requires corresponding methods of cartographical display: contours for areal impacts, lines for
linear ones, symbols and diagrams for point - source ones. We have established the optimal period for
mapping of impacts on landscapes of middle and south taiga as 50 - 100 years. This time is need for
regeneration in main features (or irreversible changing) of forest vegetation after such strong impacts
as clear cuttings and crown fires. Account must be taken of the fact of superposition of impacts which
is observed in the majority of landscapes studied.
Map of present processes in landscapes to a large measure is a result of synthesis of two
previous types of maps. Besides, the evidence of stationary investigations of processes is need for
increasing of certainty of such maps. The main principle of mapping is based on the fact that every
long - term process manifests itself in different elements of landscape (natural bodies) according to
their critical time of changing. No landscape process can be described by the only quantitative
parameters. The most informative way of landscape processes describing is using the qualitative
characteristics. It follows that the every contour of the basic landscape map is characterized by certain
qualitative properties of the processes. It makes possible showing of superposition of two and more
different processes in the same contour.
Landscape - dynamical scenario (LDS) is a method of long - term landscape dynamics
simulation (prediction) which is based on assumption: the territory for the designated future period
will not be subjected to impacts on landscapes except given by the scenario (e.g., clear cutting of all
mature stands in the area; crown fire etc) (Fig 1D). Every scenario is based on algorithm: landscape
(site) − present state − impact − result. LDS simulation is possible providing knowledge of present
processes in landscapes: their intensity, rate, manifestation in different landscape elements. It is also
need to take into account the long - term consequences of the most probable human impacts owing to
existing mode of environmental management in the region. The optimal period for LDS simulation are
10−50 years. The main principle of scenarios mapping is based on the concept, whereby long - term
consequences of any human (or natural) impact are differentiated in conformity with types of
landscapes (sites). As regards mapping it means the conformity of predicted future states and
landscape boundaries. The future of LDS simulation will be connected with broad use of GIS tools in
mapping.
The developed theoretical approaches and methods of studying and mapping of landscape
dynamics have wide application in various practical fields of activity in the North - West region of the
European Russia. Among most prominent aspects it is necessary to name landscape planning in
forestry (Leningrad and Pskov oblast), landscape investigations of the natural protected areas (St.
Petersburg and Leningrad oblast) and environmental assessment of new seaports construction projects
(Gulf of Finland).
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Gregory A. Isachenko
In course of the pilot project on landscape planning in forestry (the Pskov oblast) for the first
time in practice of forest management in Russia elementary units (contours) of forest maps were
allocated inside contours of landscape sites. Thus, planning of forestry within the limits of every
management contour (time and type of cuttings, maintenance measures, artificial reforestation etc.)
was carried out in view of landscape - dynamic features of a site.
Growstock,m3/ha
On the basis of the forest management data and landscape maps (maps of sites) models of
change of wood communities (long - term states) for the basic types of sites were created. Such model
takes into account as natural tendencies of forest regeneration, caused by properties of the site, and the
most typical impacts (mainly clear cuttings and fires). So, in the sites of drained sandy plains the share
of pine in total growstock increases with age of stands (Fig.1).
350
300
250
200
150
100
50
0
Aspen
Birch
Spruce
Pine
020
040
060
080
Age, years
100
120
Fig.1 Long-term change of total growstock and tree species composition in the site of drained plains on
sand without cobble (Pskov oblast).
Landscape investigations of the natural protected areas (St. Petersburg and Leningrad oblast)
last 5 years will be carried out and include large - scale landscape survey of the territories and
mapping on a landscape basis of a present vegetation, influences on landscapes and modern processes.
Mapping is accompanied by GIS creation for the further monitoring of natural processes and planning
of actions for conservation of a biological diversity (in particular, maintenance of populations of rare
species of plants and animals).
After 1991, in connection with the largest changes of geopolitic position of Russia, designing
and construction of large seaports was developed at coast of Gulf of Finland. Ecological support of
these works includes the complete analysis of a landscape and biological diversity of the territory,
creation of a complex of thematic maps on a landscape basis, an estimation of probable influences on
landscapes in course of construction and functioning of ports, realization of long-term landscape
monitoring. Our investigations of territory of construction of seaports Primorsk and Ust-Luga were
accompanied by creation of series of the maps including, except for base thematic maps: map of the
potential of landscape self-cleaning relative to oil pollution, map of anthropogenic impact on
vegetation, map of vegetation disturbance, map of ecological functions of vegetation, map of fire
stability of vegetation, map of the value of biocoenoses (Complex environmental mapping…, 2001;
Natural environment…, 2003).
Landscape-dynamical studies in North – Western Russia: basic results and environmental applications
51
As shown above, application of concepts of the landscape - dynamic analysis, and, in a more
comprehensive sense − the landscape - dynamic approach − gives the results allowing more deeply to
study natural and anthropogenic change of landscapes and to answer the challenges of modern
practical tasks of landscape planning and environmental assessment.
The studies are supported by Russian Foundation for Basic Research (project № 05-05-64604).
References
Complex environmental mapping of Gulf of Finland coast (Luga bay region). 2001. Eds.: E. Volkova,
V. Hramtsov. St. Petersburg: St.Petersburg Pharmaceutical State Academy publishing [Russian].
Isachenko, Gr. A. & A.I.Reznikov, 1996. Taiga of the European Russia North-West: Landscape
dynamics. St. Petersburg: Russian Geographic Society [Russian].
Natural environment of the coastal area and water body of the Gulf of Finland (Region of port
«Primorsk»). 2003. Eds.: E.Volkova, V. Hramtsov, Gr. Isachenko. St. Petersburg: Botanical Institute
RAS [Russian].
University of Saint-Petersburg
Russia
[email protected]