Ecological indicators are used to communicate information about ecosystems and the impact human activity has on ecosystems to groups such as the public or government policy makers. Ecosystems are complex and ecological indicators can help describe them in simpler terms that can be understood and used by non-scientists to make management decisions. For example, the number of different beetle taxa found in a field can be used as an indicator of biodiversity.  ^{[1] [2] [3]}

Many different types of indicators have been developed. They can be used to reflect a variety of aspects of ecosystems, including biological, chemical and physical. Due to this variety, the development and selection of ecological indicators is a complex process.  ^[4]

Using ecological indicators is a pragmatic approach since direct documentation of changes in ecosystems as related to management measures, is cost and time intensive. ^{[5] [6]} For example, it would be expensive and time consuming to count every bird, plant and animal in a newly restored wetland to see if the restoration was a success. Instead a few indicator species can be monitored to determine success of the restoration. 

“It is difficult and often even impossible to characterize the functioning of a complex system, such as an eco-agrosystem, by means of direct measurements. The size of the system, the complexity of the interactions involved, or the difficulty and cost of the measurements needed are often crippling”  ^[7]

The terms ecological indicator and environmental indicator are often used interchangeably. However, ecological indicators are actually a sub-set of environmental indicators. Generally, environmental indicators provide information on pressures on the environment, environmental conditions and societal responses. Ecological indicators refer only to ecological processes. 

Policy evaluation [edit]

Ecological indicators play an important role in evaluating policy regarding the environment.

Contributions [edit]

Indicators contribute to evaluation of policy development by: ^[8]

• Providing decision-makers and the general public with relevant information on the current state and trends in the environment.
• Helping decision-makers better understand cause and effect relationships between the choices and practices of businesses and policy-makers versus the environment.
• Assisting to monitor and assess the effectiveness of measures taken to increase and enhance ecological goods and services.

Based on the United Nations convention to combat desertification and convention for biodiversity, indicators are planned to be built in order to evaluate the evolution of the factors. For instance, for the CCD, the Unesco-funded Observatoire du Sahara et du Sahel (OSS) has created the Réseau d'Observatoires du Sahara et du Sahel (ROSELT) (website [9]) as a network of cross-Saharan observatories to establish ecological indicators.^{[citation needed]}

Limitations [edit]

There are limitations and challenges to using indicators for evaluating policy programs.

For indicators to be useful for policy analysis, it is necessary to be able to use and compare indicator results on different scales (local, regional, national and international). Currently, indicators face the following spatial limitations and challenges:

1. Variable availability of data and information on local, regional and national scales.
2. Lack of methodological standards on an international scale.
3. Different ranking of indicators on an international scale which can result in different legal treatment.
4. Averaged values across a national level may hide regional and local trends.
5. When compiled, local indicators may be too diverse to provide a national result.^[10]

Indicators also face other limitations and challenges, such as:

1. Lack of reference levels, therefore it is unknown if trends in environmental change are strong or weak.
2. Indicator measures can overlap, causing over estimation of single parameters.
3. Long-term monitoring is necessary to identify long-term environmental changes.
4. Attention to more easily handled measurable indicators distracts from indicators less quantifiable such as aesthetics, ethics or cultural values. ^[11]

See also [edit]

References [edit]

External links [edit]

• Journal of Political Ecology
• Journals of the British Ecological Society
• Institute of Ecology and Environmental Management
• Ecology and Society
• Ecology Consultants at the Open Directory Project
• U.S. EPA's Report on the Environment

v t e Modelling ecosystems – trophic components General Abiotic component Abiotic stress Behaviour Biogeochemical cycle Biomass Biotic component Biotic stress Carrying capacity Competition Ecosystem Ecosystem ecology Ecosystem model Keystone species List of feeding behaviours Metabolic theory of ecology Productivity Producers Autotrophs Chemosynthesis Chemotrophs Foundation species Mixotrophs Myco-heterotrophy Mycotroph Organotrophs Photoheterotrophs Photosynthesis Photosynthetic efficiency Phototrophs Primary nutritional groups Primary production Consumers Apex predator Bacterivore Carnivores Chemoorganotroph Foraging Generalist and specialist species Intraguild predation Herbivores Heterotroph Heterotrophic nutrition Insectivore Mesopredator release hypothesis Omnivores Optimal foraging theory Predation Prey switching Decomposers Chemoorganoheterotrophy Decomposition Detritivores Detritus Microorganisms Archaea Bacteriophage Environmental microbiology Lithoautotroph Lithotrophy Microbial cooperation Microbial ecology Microbial food web Microbial intelligence Microbial loop Microbial mat Microbial metabolism Phage ecology Food webs Biomagnification Ecological efficiency Ecological pyramid Energy flow Food chain Trophic level Example webs Cold seeps Hydrothermal vents Intertidal Kelp forests Lakes North Pacific Subtropical Gyre Rivers San Francisco Estuary Soil Tide pool Processes Ascendency Bioaccumulation Cascade effect Climax community Competitive exclusion principle Consumer-resource systems Copiotrophs Dominance Ecological network Ecological succession Energy quality Energy Systems Language f-ratio Feed conversion ratio Feeding frenzy Mesotrophic soil Nutrient cycle Oligotroph Paradox of the plankton Trophic cascade Trophic mutualism Trophic state index Defense/counter Animal coloration Antipredator adaptations Camouflage Deimatic behaviour Herbivore adaptations to plant defense Mimicry Plant defense against herbivory Predator avoidance in schooling fish

v t e Modelling ecosystems – other components Population ecology Abundance Allee effect Depensation Ecological yield Effective population size Intraspecific competition Logistic function Malthusian growth model Maximum sustainable yield Overpopulation in wild animals Overexploitation Population cycle Population dynamics Population modeling Population size Predator–prey equations Recruitment Resilience Small population size Stability Species Biodiversity Density-dependent inhibition Ecological effects of biodiversity Ecological extinction Endemic species Flagship species Gradient analysis Indicator species Introduced species Invasive species Latitudinal gradients in species diversity Minimum viable population Neutral theory Occupancy-abundance relationship Population viability analysis Priority effect Rapoport's rule Relative abundance distribution Relative species abundance Species diversity Species homogeneity Species richness Species distribution Species-area curve Umbrella species Species interaction Antibiosis Biological interaction Commensalism Community ecology Ecological facilitation Interspecific competition Mutualism Storage effect Spatial ecology Biogeography Cross-boundary subsidy Ecocline Ecotone Ecotype Disturbance Edge effects Foster's rule Habitat fragmentation Ideal free distribution Intermediate Disturbance Hypothesis Island biogeography Landscape ecology Landscape epidemiology Landscape limnology Metapopulation Patch dynamics r/K selection theory Source–sink dynamics Niche Ecological niche Ecological trap Ecosystem engineer Environmental niche modelling Guild Habitat Marine habitats Limiting similarity Niche apportionment models Niche construction Niche differentiation Other networks Assembly rules Bateman's principle Bioluminescence Ecological collapse Ecological debt Ecological deficit Ecological energetics Ecological indicator Ecological threshold Ecosystem diversity Emergence Extinction debt Kleiber's law Liebig's law of the minimum Marginal value theorem Thorson's rule Xerosere Other Allometry Alternative stable state Balance of nature Biological data visualization Constructal theory Ecocline Ecological economics Ecological footprint Ecological forecasting Ecological humanities Ecological stoichiometry Ecopath Ecosystem based fisheries Endolith Evolutionary ecology Functional ecology Industrial ecology Macroecology Microecosystem Natural environment Regime shift Systems ecology Theoretical ecology List of ecology topics