Upload
vuthuy
View
218
Download
0
Embed Size (px)
Citation preview
1
A Biodiversidade Ecologia Aplicada
Henrique Miguel Pereira Dept. Eng. Civil e Arquitectura, Instituto Superior Técnico
A biodiversidade
Biodiversidade é a variabilidade entre os organismos vivos de todas as fontes, inter alia, meio terrestre, meio marinho, e outros ecossistemas aquáticos e os complexos ecológicos de que esses organismos fazem parte; isto inclui a diversidade dentro de cada espécie, entre espécies e entre ecossistemas (Nações Unidas 1992: Artigo 2).
Biodiversidade
Serviços de Ecossistema são os benefícios que as pessoas
obtêm dos ecossistemas
Regulação Benefícios obtidos da
regulação dos processos de ecossistema
• regulação do clima • regulação de doenças • regulação de cheias
• destoxificação
Produção Bens produzidos ou aprovisionados pelos
ecossistemas
• alimento • água doce
• lenha • fibra
• bioquímicos • recursos genéticos
Culturais Benefícios não materiais obtidos dos ecossistemas
• espiritual • recreativo • estético
• inspiração • educativo • simbólico
Suporte Serviços necessários para a produção de todos os outros serviços
• Formação do solo • Ciclos dos nutrientes
• Produtividade primária
Degradation and unsustainable use of ecosystem services
Approximately 60% (15 out of 24) of the ecosystem services evaluated the MA are being degraded or used unsustainably
Provisioning services have increased at the cost of deteriorating regulating and cultural services
Service Status Food crops
livestock capture fisheries aquaculture wild foods
Fiber timber +/– cotton, silk +/– wood fuel
Genetic resources Biochemicals, medicines Fresh water
Status of Provisioning Services
Capture Fisheries
25% of commercially exploited marine fish stocks are overharvested (high certainty)
Trophic level of fish captured is declining in marine and freshwater systems
Marine fish harvest declining since the
late 1980s
Water
5 to possibly 25% of global freshwater use exceeds long-term accessible supplies (low to medium certainty)
15 - 35% of irrigation withdrawals exceed supply rates and are therefore unsustainable (low to medium certainty)
Status of Regulating and Cultural Services
Status Regulating Services Air quality regulation
Climate regulation – global
Climate regulation – regional and local
Water regulation +/– Erosion regulation
Water purification and waste treatment
Disease regulation +/– Pest regulation
Pollination
Natural hazard regulation
Cultural Services Spiritual and religious values
Aesthetic values
Recreation and ecotourism +/–
Regulating Services
Air quality regulation Ability of the atmosphere to cleanse itself of pollutants has
declined since pre-industrial times but not by more than 10% Regional and local climate regulation
Changes in land cover have affected regional and local climates both positively and negatively, but there is a preponderance of negative impacts ; for example, tropical deforestation and desertification have tended to reduce local rainfall
Water purification and waste treatment Globally, water quality is declining, although in most industrial
countries pathogen and organic pollution of surface waters has decreased over the last 20 years
Nitrate concentration has grown rapidly in the last 30 years
Pest regulation In many agricultural areas, pest control provided by
natural enemies has been replaced by the use of pesticides – such pesticide use has itself degraded the capacity of agroecosystems to provide pest control
Pollination There is established but incomplete evidence of a global
decline in the abundance of pollinators
Regulating Services
To qualify as a hotspot, a region must meet two strict criteria: it must contain at least 1,500 species of vascular plants (> 0.5 percent of the world’s total) as endemics, and it has to have lost at least 70 percent of its original habitat
To qualify as a hotspot, a region must meet two strict criteria: it must contain at least 1,500 species of vascular plants (> 0.5 percent of the world’s total) as endemics, and it has to have lost at least 70 percent of its original habitat
Valorando a biodiversidade
Valores utilitários (perspectiva antropocêntrica) Uso directo Uso indirecto Existência Valores de opção
Valores intrínsecos (perspectiva biocêntrica)
Quanta biodiversidade devemos preservar?
Tendência actual
Serviços ecossistema (excluindo valores existência)
Serviços ecossistema + valores existência
Serviços ecossistema + valores existência+
valores intrínsecos e de opção
Métodos de valoração
Técnicas convencionais de mercado Abordagem dos custo de substituição Custo de oportunidade
Técnicas de mercado implícito Método do custo de viagem Métodos de cálculo de preço hedónicos
Mercado hipotético Valoração contingente
Disponibilidade para pagar (willingness to pay)
Degradation of ecosystem services often causes significant harm to human well-being
Degradation tends to lead to the loss of non-marketed benefits from ecosystems
The economic value of these benefits is often high and sometimes higher than the marketed benefits
Timber and fuelwood generally accounted for less than a third
of total economic value of forests in eight Mediterranean
countries.
Degradation of ecosystem services often causes significant harm to human well-being
The total economic value associated with managing ecosystems more sustainably is often higher than the value associated with conversion
Conversion may still occur because private economic benefits are often greater for the converted system
Métodos decisórios
Análise custo-benefício Importância da taxa de desconto (discount rate)
Avaliação de risco O princípio precaucionário
Análise multi-critério AIA, AAE IGT
Evolução da Floresta em Portugal
Ano
1880 1900 1920 1940 1960 1980 2000
Million (Ha)
0
500
1000
1500
2000
2500
3000TOTAL Pine and other conifersEvergreen oak woodlands (montado)Oak and chestnutEucalypt
Áre
a (m
il he
ctar
es)
Pinheiros e outras coníferas
Montado
Carvalhos e castanheiro
Eucalipto
TOTAL
ÚLTIMOS 50 ANOS: Expansão significativa da floresta, com uma expansão muito significativa da área de eucalipto, substituindo áreas agrícolas ou de pinhal ardido
Economic valuation of forest services
Service/Commodity Value (million €)
Timber 257.6 Cork 221.9 Total of timber goods 479.5 Resins 13.1 Honey 5.6 Fruits 41.2 Wild mushrooms 32.5 Aromatic and medicinal plants 1.9 Game 58.7 Fodder 125.2 Acorn 6.7 Woodland production 17.8 Total of non timber goods 302.7 Recreational use 5.9 Carbon sequestration 26.5 Agricultural land protection 75 Water resources protection 29 Environmental protection 20.1 Total of environmental services 156.5 TOTAL 938.7