Sandro Lanfranco
Department of Environmental Science, GF Abela Junior
College, University of Malta, Msida.
Introduction
The present state of the natural environment of the Maltese
Islands is patchy. Seven thousand years (possibly longer) of human colonisation
have reduced the post-glacial environment of the islands to a mosaic of
highly-modified microcosms each of which is poorly representative of pre-settlement
habitats. Continuous competition for space and food between man and pre-existing
colonists has resulted in considerable habitat change with consequential
erosion (both passive as well as active) of local biodiversity. A (presumed)
typically Mediterranean habitat can now only be glimpsed in isolated and
highly degraded remnants and has for the greater part been replaced by
anthropophilic and opportunistic species.
The Human population
The human population of the Maltese Islands stands at
373719 individuals (December 1996), which translates as an overall population
density of 1183 km-2, the highest in Europe and the Mediterranean.
For much of the past 7000 years, the population size has been much lower
and as recently as 1901 numbered only 186389 individuals (as at 31 March
1901), almost precisely 50% of the 1996 figure. Much of the doubling that
occurred this century was recorded in the immediate post-war years, coincident
with rapid industrial growth.
Demand for land
The primary effect of the local population on the natural
environment has been the need for land. Since earliest times, human settlers
have cleared natural vegetation in order to accommodate their residential,
recreational, industrial and agricultural spaces. In this ongoing competition
for space, much of the characteristic vegetation (and hence, fauna) has
been replaced by a suite of opportunistic species. All other factors being
equal, agricultural land offers more opportunities for survival of remnants
of ancient populations than do residential areas. As recently as 1957,
registered agricultural land covered 56% of the surface area of the archipelago
whilst residential spaces accounted for 5%. Changing agricultural and social
practices, increasing population, rapidly increasing demands for land and
increasing standards of living have, all in all, rendered an agricultural
lifestyle less worthwhile than it was in the pre-war years. In consequence,
the area occupied by agricultural land has declined to 38% whilst by 1983,
residential areas had more than tripled the 1957 coverage and now stood
at 16%. An increased population with higher standards of living generated
a greater demand for building stone. The number of open-pit rock quarries
therefore also increased in order to meet this demand. In 1990, the number
of registered quarries was 96, but a fairly large number of other quarries
have been operating without proper licensing. The impact of quarrying on
natural landscapes is catastrophic and large tracts of countryside have
been obliterated in recent years. The demand for land has also accelerated
the destruction of any large forested areas in the archipelago. Periodic
episodes of deforestation have been recorded from all stages of the islands’
history. Indigenous population cleared forests for construction and firewood,
whilst the successive garrisons manning the islands cleared woodland for
construction of military structures, for fuel and for purposes of defence.
The comparative lack of trees has accelerated erosion of topsoil and, along
with other factors, has facilitated surface runoff of stormwater towards
the sea.
Demand for water
The biseasonal climate of the Maltese Islands is characterised
by a fairly long drought throughout the summer months, when periods of
highest temperatures coincide with periods of lowest rainfall. AS such,
pressure on the groundwater reserves of the islands has always been high
and escalated with recent increases in population size and standard of
living. In order to meet demand by households, agriculture and industry,
the sources of surface freshwaters were tapped at source and their output
redirected elsewhere. This has led to the loss of several perennial streams
and their wildlife. As water shortages became more critical, a programme
of water conservation in valleys was introduced in the 1970s. This comprised
the constriction of dams across valleys in order to hold stormwater upstream
of the dam. No concrete measures to eliminate problems arising from siltation
have been taken and the retention capabilities of several such dams has
been significantly reduced. In addition, construction of dams also led
to modification of downstream ecosystems. The sides of valleys are frequently
cultivated, and aquatic systems travelling through valley beds are subject
to leaching of biocides and fertiliser from agricultural land.
Demand for food
Throughout history, the food demands of the population
have been met by agriculture. Meat and milk could also be obtained from
cattle, goats and sheep. Goats and sheep require land for grazing and the
natural environment was (and still is, although to a lesser extent) the
main provider of such lands. As such several plants that are apparently
palatable to grazers have disappeared or declined in number and have been
replaced by a flora resistant to grazing pressures. In the past, hunting
of birds, rabbits and larger mammals may also have met some of the demand
for meat. Although the present supply of meat is far from erratic, hunting
proceeds, ostensibly for sport. No large mammals remain on the islands
and wild rabbits are also comparatively uncommon. Perceived competitors,
such as weasels, have also declined in number. The former niches of the
organisms have been taken over by smaller animals that are largely resistant
to hunting pressures due to smaller size (making them less conspicuous)
and higher reproductive rates (permitting them to comfortably absorb losses).
Demand for improved communication
Higher standards of living in the middle part of this
century resulted in an increase in the number of motor vehicles on the
roads. The number of vehicles increased from 15929 in 1957 to 117150 in
1987; a greater than sevenfold increase in three decades. The length of
roads almost doubled during this period, as former country paths were asphalted
and new highways were constructed in order to reach areas that were previously
all but inaccessible to the general public. Although the actual footprint
of roads is not great, their constriction led to considerable dissection
and subsequent fragmentation of natural landscapes. This poses a long-term
threat to several species since range fragmentation and increased habitat
insularity may both contribute to greater incidences of local extinctions.
General ignorance
Several species are now endangered as a consequence of
general ignorance of substantial proportions of the general population.
Various plants that have traditionally been perceived as being attractive
are now relatively uncommon due to over-removal from the population by
persons trying to sell them to passers-by. Conspicuous mammals such as
hedgehogs are frequently killed. Reptiles such as the wall lizard are sometimes
used for target practice, or, along with skinks and geckos, simply eliminated
through being perceived as repulsive. Intensive collection of tadpoles
from watercourses takes place and this places severe limits of populations
of the painted frog. Regrettably, much of this collection is not sporadic,
but takes place through organised "hunts" carried out by children on Sunday
School outings.
Making amends
As general awareness of the natural environment increased,
policy makers came up with various schemes to try and embellish the environment
(and their own standing). Hence a number of afforestation schemes were
designed. Unfortunately, these were frequently misguided, causing more
harm than benefit. Afforestation schemes carried out using alien species
are notorious and have facilitated the spread of such exotics as Acacia
spp. and Eucalyptus spp. In these and similar cases, natural habitats
(popularly perceived as wasteland) have been "reclaimed" through being
covered with a layer of soil. Recent legislation, dating to the early 1990s
has provided safeguards against such initiatives and also contributes to
the formation and preservation of protected areas.