Biological diversity is a result of millions of years of evolution and thousands of years of cultivation of plants and domestication of animals. For a successful, long-term conservation of an ecosystem, knowledge of its biological diversity and efforts to protect and manage that diversity is important.
Understanding biological diversity is critical for its sustainable use and safeguarding it for the benefit of future generations. The biological diversity is dynamic, continually evolving and changing in response to biotic and abiotic fluctuations and other environmental pressures. It is necessary to record in time and space its status and, subsequently, monitor it in order to identify changes and assess their impacts.
Recent years saw accelerating destruction of life on Earth which led to the signing of international agreements, such as the Convention for Biological Diversity and Agenda for increased efforts to inventory and monitor the world’s biodiversity.
Inventorying or the identification and monitoring the components of biological diversity is important for its conservation and sustainable use. Identifying and monitoring biological diversity is a huge and infinite task. The accuracy, adequacy and interpretation of inventories are important when determining the relevance of species lists to the conservation and management of biological diversity.
For example, it is crucial to identify species present in areas of natural habitat ahead of any changes in land use in order to assess what diversity may be lost from a locality. This is particularly important to tropical ecosystems, where endemic species are more and, hence the risks of species becoming globally extinct may be greater.
Inventorying is the surveying, sorting, cataloguing, quantifying and mapping of genes, individuals, populations, species, habitats, biotopes, ecosystems and landscapes or their components. The resulting information can be analysed for various processes. Inventories involve the extensive application of systematics, ecology, biogeography and management. Inventories provide a snapshot of the state of biodiversity and baseline information for the assessment of change. Recording these changes is monitoring.
To monitor a process or a dynamic system (origin: from Latin “monere” = “to remind”, “to warn”) means to observe or measure the relevant parameters which describe the change of a system adequately. Thus, monitoring is intermittent surveillance to ascertain the maintenance or changes from a predetermined standard. Monitoring of biological diversity is usually goal-oriented and provides a framework for predicting the behaviour of key variables for improving management, increasing management options and providing early warning of system change.
These attempt to identify,
record and monitor organisms and their distributions is an enormous task.
The inventories can contribute to solving the biodiversity crisis or
prioritizing areas for conservation. Human exploitation of biodiversity is currently
so high that monitoring is essential to avoid a catastrophe.
The Convention for
Biological Diversity requires signatory nations to ‘identify components of
biodiversity for conservation and sustainable use and monitor, through sampling
and other techniques, the components of biological diversity identified.’ It
also calls for signatories to ‘identify processes and categories of activities
which are likely to have significant adverse impacts on the conservation and
sustainable use of biological diversity, and monitor their effects’ and to
‘maintain and organise data derived from identification and monitoring
activities.’
Biodiversity inventories and monitoring provide the essential biological information for many biological sciences, including systematics, population biology and ecology, as well as for many applied sciences, such as biotechnology, soil science, agriculture, forestry and fisheries science, conservation and environmental sciences.
We also see inventorying and monitoring as vital for identifying key issues for policy and management goals, for example, in assessing priorities for conservation, land use and sustainable management, pollution control, environmental impact assessments, and for informing policy makers and the public on the state of biodiversity.
Historical collections of organisms provide extremely important baseline information on how the range, abundance and form of species may change over time. These are essential for the identification and verification of field data and provide a permanent record.
The need for inventorying and monitoring of biodiversity.
Over the past millennia and centuries, human activities on our planet causes rapid changes of biodiversity, including extinction of phylogenetic lineages, invasion of exotic taxa and even the spread of artificially constructed genetically manipulated organisms (GMO´s) or part of their genome.
Many of these changes are beneficial, others have negative impact on ecosystem functions, on other organisms and on goods and services, consumed by humans. Conservation, management and, monitoring of biodiversity is of high relevance for biodiversity and for sustainable development. With rising awareness of global environmental changes, monitoring data are needed for a variety of goals, including
(a) to understand the role and impact of drivers and causes of change
(b) to be able to analyze processes and mechanisms of change
(c) to lay the foundation for modeling and prediction of future changes etc.
Methods of inventorying and monitoring of biodiversity and their limitations
Methods for carrying out
inventories and monitoring at the population, species, ecosystem and landscape
level are important for understanding how that population is changing in the
face of anthropogenic disturbance.
Methods of inventorying
Inventorying or the
identification and monitoring the components of biological diversity
is important for its conservation and sustainable use. The accuracy, adequacy and
interpretation of inventories are important when determining
the relevance of species with reference to the conservation and management of biological
diversity.
Benefits
Biological
inventories provide a finer view of biological diversity and can be used to
establish national conservation programs and policies
1) These efforts tell
us the status of biodiversity, and also identify valuable biological
resources, some of which are unknown, while others are locally known but
have potential for much wider use.
2) Inventories and
surveys also provide baseline data against which to monitor
changes in biological diversity and to trace the environmental impacts of
development projects.
Assessment Methods
Status and state of a resource at a point in time is analysed and recorded in the processes biodiversity inventory.
- Distribution and composition of species, habitats and populations is measured in this process.
- The analysis can be qualitative or quantitative.
- This helps to assess the presence or infer the absence of species within an area.
A range of methods may be more or less applicable and more or less expensive.
- Censusing
and related techniques are important for estimating population size and
hence rarity/ threatened status of species.
- Species
inventories, will remain the mainstay of inventorying
and in the selection of protected, ecologically important and economically
sensitive areas.
- Remote
sensing, coupled with ground truthing, can monitor vegetation cover, land
use, forest loss and other aspects of biodiversity change at the biotope
and eco system level.
Traditional
forest inventory and vegetation analysis.
Foresters have historically developed the science of forest inventory, principally for estimates of standing volumes of wood in forests and for recurrent measurements to indicate changes with time or management; the numbers and densities of non-wood plant species are occasionally recorded. Systems of permanent and temporary sample plots in forests have sometimes been established for these forestry purposes.
Substantial work in Australia by the
Commonwealth Scientific and Industrial Research Organization (CSIRO) has
expanded such traditional forest inventories into multi-taxa surveys. There has
also been considerable international activity recently to establish
biodiversity monitoring plots e.g. United Nations Educational, Scientific and
Cultural Organization (UNESCO) Man and the Biosphere Programme; Smithsonian Institution,
Washington; and the Food and Agriculture Organization of the United Nations
(FAO).
Molecular methods.
The last decade has seen an increasing use of high
profile molecular genetic techniques to study genetic diversity, systematics
and population genetics at the DNA and protein levels. These technologies have
included isozyme, restriction fragment length polymorphism (RFLPs), randomly
amplified polymorphic DNA (RAPD), DNA fingerprinting and, more recently
micro-satellites.
Remote sensing.
A large array of technologies now exists for examination of terrestrial resources including aerial photography and satellite imagery in various electromagnetic wavebands. Their scales and precision differ but the locations and changes in forest or ecosystem boundaries can be identified easily and the standing volume of wood in some forest types can be estimated reasonably precisely. If coupled to appropriately detailed ground truthing, the techniques are applicable to identifying rare communities and vulnerable remnants, for mapping vegetation and for zonation and land use planning.
However, none of these techniques are
yet refined sufficiently to identify individual plants unequivocally at a scale
and precision that would permit biodiversity monitoring within ecosystems.
Databases and geographic information systems.
All of the historical and current data collected by any of these technologies may now be combined into electronic databases and portrayed by a large number of geographic information systems that are commercially available. One of the most intensive and extensive database systems now available appears to be the Biological and Conservation Database (BCD), of the United States Nature Conservancy - this allows rare taxa to be identified and critical sites to be recognized.
The success of such research is
dependent on the careful, repetitive and tedious recording and management of primary
data.
|
Sample |
inventory and
monitoring tools and techniques |
|
Population Species |
Censuses (observations,
counts, captures, signs, radio-tracking); remote sensing; habitat suitability
index (HSI); species-habitat modeling; population viability analysis |
|
Genetic |
Electrophoresis;
karyotypic analysis; DNA sequencing; offspring-parent regression; sib
analysis; morphological analysis |
|
Regional Landscape |
Aerial photographs
(satellite and conventional aircraft) and other remote sensing data;
Geographic Information System (GIS) technology; time series analysis; spatial
statistics; mathematical indices (of pattern, heterogeneity, connectivity,
layering, diversity, edge, morphology, autocorrelation, fractal dimension) |
|
Community Ecosystem |
Aerial photographs and
other remote sensing data; ground-level photo stations; time series analysis;
physical habitat measures and resource inventories; habitat suitability
indices (HSI, multispecies ); observations, censuses and inventories,
captures, and other sampling methodologies; mathematical indices (e.g., of
diversity, heterogeneity, layering dispersion, biotic integrity) |
Monitoring, i.e. the measurement of recent changes of biodiversity, is providing important information for an understanding of our activities. Monitoring the population sizes of protected species in their conservation areas gives feedback on the success of conservation measures. Monitoring the spread of a toxic invading species or of an infectious organism can feed into an early warning system for farmers or for medical services.
There are different
approaches to monitoring such as:
1. Neutral observation
(“What happens?”)
This approach of pure
observation can document the consequences of change, particularly of properties
of the ecosystem such as soil quality, microclimate, land use. New observations
such as the impact of rare events can also be considered in this pure
observation approach
2. Early warning system (“When must we
take action?”)
Change of biodiversity
can have important consequences for ecosystem function and use of resources. Single
events can cause cascades of secondary effects, and transitions from one phase
of a system into another new phase may take place suddenly once thresholds have
been passed (e.g. state of an ecosystem, size of a population or area of distribution).
Therefore, an observation system should serve as an early warning system, which
allows action to be taken well before irreversible damage has taken place.
3. Indicators of biodiversity change
(“What is important?”)
The observation or
measurement of a limited set of specific qualities and/or quantities that can
act as indicators is a more practical approach because observation of a large
number of parameters and processes requires large investments of time and
manpower.
4. Causality approach (“Why does change
happen?”)
Observation of the type
and intensity of change within a given ecosystem can allow identification of
the drivers/causes of change such as specific climatic changes, specific land use
practices.
5. Process analysis (“How does change
happen?”)
If observation is
designed to provide additional scientific understanding of the mechanisms and
processes of change, more detailed studies are needed. The resulting knowledge
can also form the basis for the prediction of future developments:
6. Model-based approach (“Do we understand
the full picture?”)
Observations can be used
to test (verify or falsify) and validate results based on models.
7. Experimental approach (“How can we
intervene?”)
One of the ultimate goals
of biodiversity research is the implementation of sustainable use and
conservation of biodiversity. For this purpose, observation can integrate a
variety of experimental approaches for testing and measuring vulnerability,
resilience, restorability and other system properties. If successful, this
approach help in deriving management recommendations.
Examples of monitoring at each Biodiversity level
1. Landscape Monitoring
Landscape diversity is the number of ecosystems, or combinations of ecosystems, and types of interactions and disturbances present within a given landscape. Two approaches to assessing biological diversity at a landscape scale include measuring landscape patterns and comparing current conditions to historic reference conditions. Each of these approaches relies on the use of geographic information systems (GISs) and requires mapped vegetation and other layers that can be analyzed with GIS technologies.
2. Community-Ecosystem Monitoring
A community comprises the populations of some or all species coexisting at a site. An ecosystem includes the abiotic aspects of the environment and the biotic community. Monitoring at this level is important to the maintenance of ecosystem functions and integrity that have been identified as a main theme of ecosystem management. A common way of assessing biodiversity is by measuring the number and relative abundance of species in a community or ecosystem, often referred to as species diversity. Species diversity is a function of the number of species present (richness) and the evenness or equitability (relative abundance) of each.
3. Diversity Indices
In
general, three main categories of measures are used to assess species
diversity: (1) species richness indices, which measure the number of species in
a sampling unit; (2) species abundance models, which have been developed to
describe the distribution of species abundances; and (3) indices that are based
on the proportional abundances of species such as the Shannon and Simpson
indices.
To
quantify community-level biodiversity, an inventory or sample of the species
present and their relative abundance must be completed. Various methods have
been used to Inventory plant, wildlife, and fish species.
Some
investigators have taken a different viewpoint by lumping species into
functional groups or guilds. Many approaches for grouping species based on
habitat or behavioral similarities and their potential problems. Species are
grouped into guilds based on their function in the ecosystem, and then the
relative importance of each guild is considered based on how a change in their
abundance affects ecosystem and community process.
They
estimated species richness of spiders, ants, polychaetes, and mosses, and
divided them into recognizable taxonomic units (RTUs). These RTUs are taxa that
are readily separated by morphological differences that are obvious to
individuals with less training than professional taxonomists. They found that
by using RTUs, there is little difference between classifications made by a
biodiversity technician and those made by a taxonomy specialist. This could
result in a considerable savings of time and money to complete the inventories
needed to assess this one facet of biological diversity. This technique could
be applied at different time periods to monitor the trends in the numbers of
individuals within RTUs.
Gap analysis, provides a framework in which to obtain an overview of the distribution and conservation status of several components of biodiversity. The approach involves mapping, digitizing, and ground-truthing vegetation and species distribution data; digitizing biodiversity management areas and landownership maps; adding location data on all species and high-interest habitats such as wetlands and streams; and mapping, delineating, and ranking areas of high community diversity and species richness. These data are then used to identify "gaps" in protection of vegetation types and species-rich areas and provide land managers with information needed to make informed decisions about reserve selection and design, land management policy, and other conservation actions.
7. Abundance Indices
An index is usually a count statistic that is
obtained in the field and carries information about a population. Abundance
indices are divided into direct indices and indirect indices. Direct indices
are based on direct observation of animals, either visually or through capture
or harvest. ndirect indices are based on evidence of an animal’s presence.
Population viability analysis (PYA) estimates
the conditions necessary for a population to persist for a given period of time
in a given place
Genetic diversity refers to the breadth of genetic variation within and among individual populations and species
10.Variation in DNA
The development of recombinant DNA technologies allows the direct measurement of genetic variation, which differs from indirect methods such as estimation of variation from a phenotype. analysis of mitochondrial DNA has been used to deduce population structure.
The constantly moving and three-dimensional nature of the aquatic and marine environments presents challenges in the process of inventory and monitoring. Biological organisms are not restricted by political boundaries. Long-term research sites and programmes provide essential information on how biodiversity changes, and are important in distinguishing anthropogenic from natural change.
If institutions concerned with inventorying and monitoring are to become more effective, they need to be better resourced, their collections better maintained and a new cadre of professional researchers and technicians trained and funded. There should be a sharing of scientific expertise, facilities and information by collaboration between nations and agencies, if we are to follow international agreements on inventorying and monitoring biodiversity.
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