Research was conducted in three areas of water quality assessment. Long term ecological monitoring data from Shenandoah National Park (SNP) were analyzed and a protocol for data analysis was presented. Streams in SNP were found to be comparable to the best that can be found in the Blue Ridge ecoregion. Land use in SNP (mostly for recreational purposes) does not appear to be causing impairment to the macroinvertebrate assemblages. Streams in the SNP were found to recover quickly from disturbance. The Macroinvertebrate Aggregated Index for Streams (MAIS) was found to have an overall classification efficiency (CE) of 86% in the Ridge and Valley ecoregion, and an overall CE of 91% in the Central Appalachians ecoregion. Refinement of the MAIS for use in the Blue Ridge ecoregion resulted in an increase of the overall CE to 78%. The CE for reference sites in the Blue Ridge was 75%, and the CE for degraded sites was 87%. An intensive study of a stream (Peak Creek) with suspected heavy metal impairment showed that capping of an industrial waste site has resulted in improvements to the macroinvertebrate assemblages. The source of the impairment was not linked solely to heavy metals, but was found to be a mixture of pollution sources and environmental stress. / Ph. D.

Acid mine drainage (AMD) is a major environmental issue worldwide. On the West Coast of the South Island, New Zealand, numerous catchments receive AMD, with significant negative impacts on in-stream flora and fauna. Diatoms are commonly regarded as powerful biological indicators and may be found in high abundance in AMD-contaminated streams; however, relatively little work has been done on diatoms in mining environments in New Zealand. Initially, I conducted a survey of epiphytic diatom communities in 39 streams ranging from non-impacted reference streams to those severely impacted by AMD. Streams were assigned to one of four classes along an AMD gradient: circum-neutral reference, naturally acidic reference, moderately impacted, and severely impacted. There was a wide range in diatom taxonomic richness in reference and moderately impacted streams (8 – 33 taxa). Taxonomic richness was greatly reduced in severely impacted streams (1 – 5 taxa) at a threshold of pH 3.4 and was dominated by Pinnularia cf. acidophila (69 – 100% relative abundance). Community composition differed between circum-neutral reference, moderately, and severely impacted streams; however, naturally acidic and moderately impacted streams had similar diatom communities primarily composed of acid-tolerant Eunotia and Frustulia species. This indicated that diatoms are strongly structured by pH and able to tolerate moderate conductivity and metal concentrations without a corresponding shift in community composition. Survey data were then used to develop two diatom-based indices for streams impacted by AMD: a single Biotic Index and a Multimetric Index. While neither index was able to distinguish naturally acidic from moderately impacted streams, both indices successfully categorised streams as circum-neutral reference, moderately or severely impacted by AMD. These indices may be useful in assessing AMD impact on circum-neutral streams or in identifying when a stream has crossed a threshold from moderately to severely impacted by AMD. Diatoms would be especially useful as bioindicators of AMD if they respond rapidly to a change in mine discharge. To test this, mature algal biofilms were reciprocally transferred between circum-neutral reference streams and streams of varying degrees of AMD over a period of 13 days. Diatom mortality increased rapidly in the reciprocal transfer between reference and severely impacted streams. Reference communities resembled the ambient diatom community of severely impacted streams 13 days post-transfer. However, in the reverse transfer, a change in community composition was slow to occur. Diatoms respond faster to an increase in pollution than to pollution amelioration. Overall, results indicated that diatom communities may be a useful tool for monitoring the presence and magnitude of AMD in New Zealand streams.

An increase in public environmental awareness and a decrease in resources within government regulatory agencies have led to a larger interest in volunteer biomonitoring programs. Government agencies are currently using volunteer data for official purposes with increasing frequency, but questions have been raised about the validity of the data collected by volunteers who have only limited training and experience. Therefore, we conducted a detailed study to assess, modify, and validate the Virginia Save-Our-Streams (SOS) program, which is a volunteer organization collecting macroinvertebrate data. Sites were sampled using professional methods concurrently with volunteers who utilized the SOS protocol. The volunteer samples were retained for further laboratory analysis. In addition, numerous sites previously sampled by volunteers were re-sampled using professional methods. The data were statistically analyzed to determine if the results of volunteers and professional aquatic biologists were correlated and if they arrived at the same conclusions about ecological condition. It was determined that the Virginia SOS method, and probably other similar volunteer methods, consistently overrate ecological condition. This means that streams impaired by pollution could go unreported, if they are monitored exclusively by volunteers. The cause of this overestimation was determined to be the overly simplistic SOS metric, which is based solely on the presence or absence of taxa. The SOS protocol for data analysis was made more quantitative by developing a multimetric index that is appropriate for use by volunteers. The SOS sampling protocol was modified slightly to obtain actual counts of the different kinds of macroinvertebrates, which allowed for calculation of metrics. Sorting effort and taxonomic level of identification were not changed so that currently participating volunteers would not be excluded because of the need for expensive equipment or advanced technical training. The modified SOS protocol was evaluated by a different set of concurrent samples taken by volunteers and professionals, but using the same statistical techniques. The modified SOS protocol proved to be feasible for volunteers. The new SOS multimetric index correlated well with a professional multimetric index. The conclusions about ecological condition derived from the volunteer multimetric index agreed very closely with those made by professional aquatic biologists. This study demonstrated that volunteer biomonitoring programs can provide reliable data, but every volunteer program needs to be thoroughly validated by statistical comparisons to the professional methods being used in that area. / Master of Science

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2014-10-01T15:50:01Z No. of bitstreams: 2 Tese - Allan Valle Toledo da Silveira - 2013.pdf: 1647435 bytes, checksum: 49a815f9117230a88dd9f9443c919f33 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Jaqueline Silva (jtas29@gmail.com) on 2014-10-01T16:46:58Z (GMT) No. of bitstreams: 2 Tese - Allan Valle Toledo da Silveira - 2013.pdf: 1647435 bytes, checksum: 49a815f9117230a88dd9f9443c919f33 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2014-10-01T16:46:58Z (GMT). No. of bitstreams: 2 Tese - Allan Valle Toledo da Silveira - 2013.pdf: 1647435 bytes, checksum: 49a815f9117230a88dd9f9443c919f33 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2013-04-05 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / This thesis evaluated the variables that influence the distribution of aquatic insects, along different spatial scales, aiming to establish a biologic index of water quality based on these organisms. The study area was the Rio dos Bois watershed, one of the most important from Goiás State, due to its vocation for agricultural and cattle production. Thus, the community of aquatic insects occurring in forty two streams was sampled, as well as a series of water physicochemical variables. Surrounding the streams (up to a distance of 200 m), and along the watershed above the sampling units, percentages of land use (agriculture, pasture and native vegetation) were estimated based on LandSat 5/TM satellite images from July 2012. The main results showed that (1) smaller spatial scales seem to provide better estimates of water quality and aquatic insects community than the watershed level scale, being recommended to use habitat integrity indexes (HII); (2) the variance partition held to define the contribution of the spatial processes and environmental variables on the community structure of aquatic insects did not present statistically significant values to corroborate none of the two sets of predictors and (3) only four from the 26 biodiversity metrics studied were enough to compose a multimetric index for the watershed, (% Plecoptera, Ephemeroptera richness, EPT richness and the BMWP/ASPT index). (4) Based on this index, it was possible to classify the streams from the study area as very disturbed (41%), with intermediate impacts (46%) and minimally disturbed (13%). This study may contribute to future studies of biomonitoring and conservation of water resources in the Goiás State and Brazil. / escalas espaciais, na tentativa de estabelecer um índice biológico de qualidade de água baseado nesses organismos. A área de estudo adotada foi a Bacia Hidrográfica do Rio dos Bois, uma das mais importantes do estado de Goiás, devido a sua vocação agropecuária. Desta forma, a comunidade de insetos aquáticos pertencentes a quarenta e dois córregos foi amostrada, bem como uma série de variáveis físico químicas da água . Nos arredores dos córregos (até 200 m de distância), bem como em toda a bacia à montante do local amostrado, porcentagens de classes de uso de solo (agricultura, pecuária e vegetação) foram estimadas a partir de imagens de satélite LandSat 5/TM datadas de julho de 2012. Os principais resultados evidenciam que (1) escalas espaciais menores parecem ser melhores preditores da qualidade da água e das comunidades de insetos aquáticos do que a escala ao nível de bacia, sendo recomendada a utilização de índices de integridade ambiental (IIA); (2) a partição de variância realizada para determinar as contribuições dos processos espaciais e variáveis ambientais na estruturação da comunidade de insetos aquáticos não apresentou valores estatisticamente significativos para corroborar nenhum dos dois conjuntos de preditores e (3) apenas quatro de 26 métricas de biodiversidade estudadas foram satisfatórias para compor um índice multimétrico para a bacia, (% Plecoptera, riqueza de Ephemeroptera, riqueza de EPT e o índice BMWP/ASPT). (4) Baseado neste índice, pôde-se classificar os córregos da área estudada como: muito impactadas (41%), com impactos intermediários (46%) e minimamente impactadas (13%). Acredita-se que este estudo possa contribuir para futuros estudos de biomonitoramento e conservação de recursos hídricos no estado de Goiás e no Brasil.

O Pantanal é um complexo de ecossistemas que exibe grande diversidade de ambientes aquáticos. O objetivo geral deste estudo foi caracterizar a estrutura da comunidade de peixes no Parque Nacional do Pantanal Mato-grossense (PNPM), uma Unidade de Conservação federal localizada no município de Poconé, MT, a fim de apoiar a construção de um instrumento de monitoramento baseado na integridade biótica do ambiente aquático. Tal objetivo foi obtido através da adaptação do Índice de Integridade Biótica para o PNPM (IIBPNPM). Previamente ao capítulo sobre a construção do IIBPNPM, que se espera representativo para uma porção ainda intocada do Pantanal, os dois primeiros capítulos fornecem os dados necessários para subsidiar a aplicação do índice. O primeiro trata da caracterização dos diferentes ambientes que ocorrem no PNPM, agrupados em quatro estratos ambientais: rios principais (rios Cuiabá e Paraguai), corixos (canais de ligação da planície de inundação), baías permanentes (não perdem a conexão na seca) e baías temporárias (aquelas que perdem conexão com os outros elementos da planície). Essa caracterização foi realizada na primeira campanha exploratória ao PNPM, em setembro de 2009, quando foram definidos os pontos de amostragem de água e de peixes. Testes estatísticos foram realizados para verificar a existência de associação entre os diferentes estratos e os fatores abióticos (variáveis físicas e químicas da água), porém, não foram significativos, indicando que os ambientes são homogêneos. As coletas de peixes foram realizadas em 12 pontos dentro do PNPM, no período seco, no final de outubro e início de novembro de 2010 e 2011. No segundo capítulo, foram identificadas 154 espécies de peixes, totalizando 19.839 indivíduos, das quais 146 espécies (18.954 exemplares) foram consideradas para a construção do IIBPNPM, por questões de padronização dos petrechos de pesca. Testes estatísticos também não evidenciaram associação entre a estrutura das assembleias de peixes e os estratos, reforçando a hipótese da homogeneidade dos ambientes. No entanto, os índices de diversidade de Shannon (H) e equabilidade de Pielou (J) foram significativamente diferentes entre os estratos. A homogeneidade dos ambientes pode ser explicada pelo fato do PNPM estar situado num pantanal de alta inundação, que pode durar até oito meses de um único ciclo hidrológico. Analisando o que os resultados indicaram, os poucos meses de estiagem parecem não ser suficientes para gerar variablidade ambiental detectável pelos métodos utilizados. O IIBPNPM final é composto por nove métricas e três classes de integridade biótica: excelente, regular e pobre, com intervalos específicos de pontuação. A maioria das métricas se enquadrou na classe excelente, algumas na classe regular e nenhuma na classe pobre, o que era esperado pelo fato de não haver indícios de degradação ambiental no interior do PNPM. A comunidade de peixes, portanto, é bem estruturada, rica e abundante. Não houve diferença significativa nas pontuações do IIBPNPM entre os anos (2010 e 2011). Embora a localização privilegiada do PNPM amorteça o efeito dos impactos antrópicos, eles estão presentes de maneira difusa em todo o Pantanal, com intensidade e magnitude diversas. Aliado a isso, há de se levar em conta que o PNPM é uma área de berçário de muitas espécies de peixes, e exerce papel fundamental no recrutamento de recursos pesqueiros. Por isso, recomenda-se aos gestores do PNPM a implementação de um programa de monitoramento ambiental que tenha a ictiofauna como indicadora dos processos ecológicos. Nesse sentido, a aplicação sistematizada do IIBPNPM pode auxiliar na síntese das informações e na comunicação dos resultados à sociedade. / The Pantanal is a complex of ecosystems that displays high diversity of aquatic habitats. The overall objective of this thesis was to characterize the structure of the fish assemblages in the Pantanal National Park, a federal protected area located in the state of Mato Grosso, Brazil, to back up the construction of a monitoring instrument based on the biotic integrity of the aquatic environment. This objective was achieved by adapting the Index of Biotic Integrity for the Pantanal National Park habitats. Prior to the chapter on the construction of this index (IIBPNPM), expected to be representative of a quite pristine Pantanal portion, the first two chapters provide the necessary data to support the application of the index. The first one deals with the characterization of the different hábitats that occur in PNPM, grouped into four environmental strata: main rivers (Cuiabá and Paraguai rivers), corixos (channels that connect the floodplain elements), permanent bays (do not lose the river connection in the dry season) and temporary bays (lose the connection in the dry season). This characterization was performed in the first PNPM exploratory campaign, in September 2009, when the future sampling sites were defined by collecting water and fish. Statistical tests were performed aiming to detect the existence of an association between the different strata and abiotic factors (water quality variables). However, they were not significant, indicating that the hábitats are homogeneous. Fish sampling were performed at 12 points within the PNPM, during the dry season in late October and early November of 2010 and 2011. In the second chapter, we identified 154 species of fish, totaling 19,839 individuals from which 146 species (18,954 individuals) were considered for the IIBPNPM framing for reasons of standardization of the fishing gears. Statistical tests also showed no association between the structure of the fish assemblage and strata, reinforcing the hypothesis of homogeneity of environments. However, the Shannon diversity index (H\') and evenness (J) were significantly different between the strata. The homogeneity of the environments can be explained by the PNPM being located in a wetland of high flooding, which can last up to eight months of a single hydrological cycle. Analyzed results indicate that the few dry months are not sufficient to generate environmental variability detectable by the methods used. The final IIBPNPM consists of nine metrics and three classes of biotic integrity: \"excellent\", \"regular\" and \"poor\", with specific ranges of scores. Most metrics are framed in \"excellent\" class, some in \"regular\" and none in \"poor\" one, which was expected because there was no evidence of environmental degradation within the PNPM. The fish community is well structured, rich and abundant. There was no significant difference in scores between IIBPNPM years (2010 and 2011). Although the location of PNPM cushions the effect of human impacts, they are present in a diffuse manner throughout the Pantanal, with various intensities and magnitudes. Allied to this, one should take into account that the PNPM is a nursery area for many fish species, and plays an essential role in the recruitment of fishery resources. Therefore, we emphatically recommend to the PNPM managers that implement an active monitoring program considering the fish assemblage as an indicator of ecological processes. The periodic performance of IIBPNPM can assist in summarizing information and to communicate the results to society.

O Pantanal é um complexo de ecossistemas que exibe grande diversidade de ambientes aquáticos. O objetivo geral deste estudo foi caracterizar a estrutura da comunidade de peixes no Parque Nacional do Pantanal Mato-grossense (PNPM), uma Unidade de Conservação federal localizada no município de Poconé, MT, a fim de apoiar a construção de um instrumento de monitoramento baseado na integridade biótica do ambiente aquático. Tal objetivo foi obtido através da adaptação do Índice de Integridade Biótica para o PNPM (IIBPNPM). Previamente ao capítulo sobre a construção do IIBPNPM, que se espera representativo para uma porção ainda intocada do Pantanal, os dois primeiros capítulos fornecem os dados necessários para subsidiar a aplicação do índice. O primeiro trata da caracterização dos diferentes ambientes que ocorrem no PNPM, agrupados em quatro estratos ambientais: rios principais (rios Cuiabá e Paraguai), corixos (canais de ligação da planície de inundação), baías permanentes (não perdem a conexão na seca) e baías temporárias (aquelas que perdem conexão com os outros elementos da planície). Essa caracterização foi realizada na primeira campanha exploratória ao PNPM, em setembro de 2009, quando foram definidos os pontos de amostragem de água e de peixes. Testes estatísticos foram realizados para verificar a existência de associação entre os diferentes estratos e os fatores abióticos (variáveis físicas e químicas da água), porém, não foram significativos, indicando que os ambientes são homogêneos. As coletas de peixes foram realizadas em 12 pontos dentro do PNPM, no período seco, no final de outubro e início de novembro de 2010 e 2011. No segundo capítulo, foram identificadas 154 espécies de peixes, totalizando 19.839 indivíduos, das quais 146 espécies (18.954 exemplares) foram consideradas para a construção do IIBPNPM, por questões de padronização dos petrechos de pesca. Testes estatísticos também não evidenciaram associação entre a estrutura das assembleias de peixes e os estratos, reforçando a hipótese da homogeneidade dos ambientes. No entanto, os índices de diversidade de Shannon (H) e equabilidade de Pielou (J) foram significativamente diferentes entre os estratos. A homogeneidade dos ambientes pode ser explicada pelo fato do PNPM estar situado num pantanal de alta inundação, que pode durar até oito meses de um único ciclo hidrológico. Analisando o que os resultados indicaram, os poucos meses de estiagem parecem não ser suficientes para gerar variablidade ambiental detectável pelos métodos utilizados. O IIBPNPM final é composto por nove métricas e três classes de integridade biótica: excelente, regular e pobre, com intervalos específicos de pontuação. A maioria das métricas se enquadrou na classe excelente, algumas na classe regular e nenhuma na classe pobre, o que era esperado pelo fato de não haver indícios de degradação ambiental no interior do PNPM. A comunidade de peixes, portanto, é bem estruturada, rica e abundante. Não houve diferença significativa nas pontuações do IIBPNPM entre os anos (2010 e 2011). Embora a localização privilegiada do PNPM amorteça o efeito dos impactos antrópicos, eles estão presentes de maneira difusa em todo o Pantanal, com intensidade e magnitude diversas. Aliado a isso, há de se levar em conta que o PNPM é uma área de berçário de muitas espécies de peixes, e exerce papel fundamental no recrutamento de recursos pesqueiros. Por isso, recomenda-se aos gestores do PNPM a implementação de um programa de monitoramento ambiental que tenha a ictiofauna como indicadora dos processos ecológicos. Nesse sentido, a aplicação sistematizada do IIBPNPM pode auxiliar na síntese das informações e na comunicação dos resultados à sociedade. / The Pantanal is a complex of ecosystems that displays high diversity of aquatic habitats. The overall objective of this thesis was to characterize the structure of the fish assemblages in the Pantanal National Park, a federal protected area located in the state of Mato Grosso, Brazil, to back up the construction of a monitoring instrument based on the biotic integrity of the aquatic environment. This objective was achieved by adapting the Index of Biotic Integrity for the Pantanal National Park habitats. Prior to the chapter on the construction of this index (IIBPNPM), expected to be representative of a quite pristine Pantanal portion, the first two chapters provide the necessary data to support the application of the index. The first one deals with the characterization of the different hábitats that occur in PNPM, grouped into four environmental strata: main rivers (Cuiabá and Paraguai rivers), corixos (channels that connect the floodplain elements), permanent bays (do not lose the river connection in the dry season) and temporary bays (lose the connection in the dry season). This characterization was performed in the first PNPM exploratory campaign, in September 2009, when the future sampling sites were defined by collecting water and fish. Statistical tests were performed aiming to detect the existence of an association between the different strata and abiotic factors (water quality variables). However, they were not significant, indicating that the hábitats are homogeneous. Fish sampling were performed at 12 points within the PNPM, during the dry season in late October and early November of 2010 and 2011. In the second chapter, we identified 154 species of fish, totaling 19,839 individuals from which 146 species (18,954 individuals) were considered for the IIBPNPM framing for reasons of standardization of the fishing gears. Statistical tests also showed no association between the structure of the fish assemblage and strata, reinforcing the hypothesis of homogeneity of environments. However, the Shannon diversity index (H\') and evenness (J) were significantly different between the strata. The homogeneity of the environments can be explained by the PNPM being located in a wetland of high flooding, which can last up to eight months of a single hydrological cycle. Analyzed results indicate that the few dry months are not sufficient to generate environmental variability detectable by the methods used. The final IIBPNPM consists of nine metrics and three classes of biotic integrity: \"excellent\", \"regular\" and \"poor\", with specific ranges of scores. Most metrics are framed in \"excellent\" class, some in \"regular\" and none in \"poor\" one, which was expected because there was no evidence of environmental degradation within the PNPM. The fish community is well structured, rich and abundant. There was no significant difference in scores between IIBPNPM years (2010 and 2011). Although the location of PNPM cushions the effect of human impacts, they are present in a diffuse manner throughout the Pantanal, with various intensities and magnitudes. Allied to this, one should take into account that the PNPM is a nursery area for many fish species, and plays an essential role in the recruitment of fishery resources. Therefore, we emphatically recommend to the PNPM managers that implement an active monitoring program considering the fish assemblage as an indicator of ecological processes. The periodic performance of IIBPNPM can assist in summarizing information and to communicate the results to society.

En la presente tesis se muestrearon ríos sobre los 2000 msnm (ríos altoandinos tropicales) que se distribuyen en la amplia región de los Andes del Norte (Ecuador) y los Andes Centrales (Perú) en Sudamérica. El muestreo de las 123 localidades se realizó en época seca, las cuales se seleccionaron tomando en cuenta su grado de alteración, que van desde sin o poca alteración (referencia) hasta muy alterados. En una primera instancia se analizaron las carácteristicas fisicoquímicas e hidromorfológicas de los ríos, las cuales mostraron una alta influencia de la altitud. Se registraron reducciones en la temperatura y oxígeno a medida que la altitud se incrementaba, por otra parte las diferencias en la heterogeneidad de los hábitats, así como la calidad del bosque de ribera fueron dos factores con un alta importancia al momento de caracterizar los ríos altoandinos. Se econtraron diferencias en la mineralización en los diferentes dominios morfotectónicos, siendo más elevados los valores de conductividad en las zonas del sur, debido a la geomorfología propia de cada zona. La comunidad bentónica mostro estar altamente influenciada por la altitud y la latitud. La altitud mostró intervenir positiva o negativamente en la abundancia y frecuencia de algunos géneros como Hyalella, Podonomopsis, Claudioperla, Anomalopsyche, Paltostoma, Rheotanytarsus, Camelobaetidius, etc. Por su parte, la latitud reveló la tendencia de algunos taxa a disminuir o aumentar su abundancia y frecuencia, tal es el caso de Anacroneuria, Camelobaetidius, Anchytarsus, Hagenulopsis, Claudioperla, Austrelmis, Smicridea, etc. Por otra parte y como punto novedoso para el conicimiento de la zona de estudio, se analizó a la familia Chironomidae a nivel de género, hecho importante para el conocimiento taxónomico de la familia en ríos tropicales de los Andes sobre los 2000 msnm, ya que no hay trabajos a este nivel taxonómico en la zona altoandina. La familia Chironomidae mostro patrones similares a los de la comunidad bentónica en general, sindo los factores relacionados con la altitud (oxígeno y temperatura) lo que determinan en gran medida su distrbución, sin embargo, al igua que el resto de la comunidad la heterogenidad de hábitats mostraron ser de suma importancia para la familia de los quironómidos. Además, la litografía y la biogeografía fueron dos factores que determinan la composición de esta familia. Con esta visión general, se analizaron los patrones de biodiversidad de estos ríos, donde se determinó que la comunidad bentónica altoandina tiene una amplia variabilidad en la diversidad local mientras que si analizamos la diversidad Gamma hay una tendencia a disminuir tanto a medida que la altitud y la latitud aumentan. Por su parte se evidenció cambios en la composición de la comunidad, la cual fue evidente también en ambos gradientes, sin embargo debido a la amplia heterogeneidad ambiental fue necesario analizar la reposición de especies a diferentes escalas de agrupación ya que sin esta corrección los cambios ambientales locales no permiten visualizar los patrones existentes en la comunidad, indicandonos la importancia de los factores locales en la biodiversidad regional. Finalmente, y con la recopilación de la estructura, composición y distribución de la fauna béntica, así como de la variabilidad ambiental tanto natural como antropogénica, se desarrolló un índice multimétrico que nos permite evaluar la calidad ecológica de los ríos altoandinos aplicable a una zona geográfica amplia. Los análisis previos al desarrollo del índice multimétrico demostraron que la variabilidad de la zona alta (localidades de páramo y puna) y la zona baja (localidades de bosque montano) era diferente. Posteriormente usando a las comunidades de macroinvertebrados acuáticos de las localidades de referencia se determinaron a dichas zonas como tipologías diferentes, las cuales se usaron para desarrollar el IMEERA-B (Bosque) y el IMEERA-P (Páramos y Punas). En nuestro estudio en la zona baja el gradiente de presión está determinado por la contaminación orgánica y la degradación hidromorfológica, y en la zona alta el gradiente está influenciado por la contaminación orgánica y la heterogeneidad del hábitat. Finalmente, se determinaron 6 métricas para IMEERA-B que evalúan la riqueza, el hábito y la tolerancia/intolerancia, y para el IMEERA-P se determinaron 4 métricas que evalúan la riqueza y la tolerancia/intolerancia. / STRUCTURE AND COMPOSITION OF AQUATIC MACROINVERTEBRATES COMMUNITIES IN HIGHLAND ANDEAN RIVERS OF ECUADOR AND PERU. DESIGN OF A MEASURE OF WATER QUALITY WITH MULTIMETRIC INDEXES In this thesis we sampled Highland Andean Rivers above 2000 m a.s.l. (tropical andean highland rivers) which are distributed in a wide geographical region of the North Andes (Ecuador) and Central Andes (Peru) in South America. In total 123 sites were sampled in dry season, which were selected taking into account the anthropogenic influence gradient, ranging from no alteration, little alteration (i.e., reference) to highly altered. The physico-chemical caracteristics of rivers showed a high altitud influence. We recorded a decrease in both temperature and oxygen as altitude increases. Habitat heterogeneity and the riverine forest quality were identified as determinant enviromental characteristics regarding the andean higland rivers studied. The mineralization show differences between the morphotectonics groups, while were the conductivity was higher at the south, depending on the geomorphology of each zone. The sampled macroinvertebrate assemblages were influenced by both latitudinal and altitudinal gradients. In detail, assemblages showed different gradient responses (positive or negative), depending of the organism and its requirements. The patterns of abundance and richness are probably determined by the environmental variability observed, and described by the temperature, oxygen, habitat heterogeneity and the presence, and absence of riverine forest. The family Chironomidae, as we expected, showed different responses depending of the genus, while the composition of the family was determined mainly by temperature, oxygen, lithography. and biogeography. We also studied the biodiversity patterns of Highland Andean Rivers rivers. The benthic community assemblage showed a high variability at local diversity (alpha diversity), while the gamma diversity decreased in both latitude and altitude gradients. Moreover, the community presented some discontinuities in the beta diversity. Regarding latitudinal gradient, the composition of assemblage changed in each morphological group, while altitude changes were described by vegetation types (mountain forest or páramo-puna) or presence or absence of riverine forest. Finally, using the aquatic macroinvertebrate communities of the reference sites, two different zones were identified as distinct from each other: from 2000 to 3500 m a.s.l and those sites at altitudes higher than 3500 m a.sl.. For such reasons two versions of a multi-metric index - the IMEERA index - were developed. The IMEERA B index includes six metrics evaluating richness, habit and tolerance/intolerance. The IMEERA P index was calculated using four metrics evaluating richness and tolerance/intolerance. Results showed that in lower altitudes (Bosque river type, IMEERA-B index), the pressure gradient was driven by the organic pollution and the hydromorphological degradation, while in higher altitudes (Páramo and Puna river types; IMEERA-P river type), the gradient was driven by the organic pollution and the habitat heterogeneity.

Το αντικείμενο της παρούσας διδακτορικής διατριβής είναι η οικολογική αξιολόγηση δύο ποτάμιων οικοσυστημάτων του Αχέροντα και του Λούρου, με βάση τις κοινότητες υδρόβιων μακροφύτων, την ποιότητα του νερού και τα υδρογεωμορφολογικά χαρακτηριστικά, καθώς και η ανάπτυξη και η οριστικοποίηση μεθοδολογίας για τη συλλογή, την επεξεργασία, την ανάλυση και την αξιολόγηση των δεδομένων πεδίου προσαρμοσμένης και εφαρμόσιμης στις ελληνικές συνθήκες. Οι επιμέρους στόχοι της διδακτορικής διατριβής διακρίνονται σε 4 επί μέρους κεφάλαια. Το πρώτο κεφάλαιο (Κεφάλαιο Α) αφορά τη διερεύνηση των αβιοτικών παραμέτρων που επηρεάζουν την κατανομή των υδρόβιων μακροφύτων κατά μήκος των δύο λεκανών απορροής. Στο δεύτερο κεφάλαιο (Κεφάλαιο Β) πραγματοποιείται διερεύνηση της δομής της παρόχθιας ζώνης και εκτίμηση των βασικών προτύπων οικολογικής διαβάθμισης και ανθρώπινης παρέμβασης. Στο τρίτο κεφάλαιο (Κεφάλαιο Γ) πραγματοποιείται αβιοτική τυπολογική διάκριση των θέσεων δειγματοληψίας με σκοπό τη μείωση της χωρικής διακύμανσης, έλεγχο της διαχρονικής και εποχικής διακύμανσης στην κατανομή των υδρόβιων μακροφύτων και καθορισμός των κοινοτήτων αναφοράς σε κάθε τμήμα του ποτάμιου οικοσυστήματος. Τέλος στο τέταρτο κεφάλαιο (Κεφάλαιο Δ) δίνεται η μεθοδολογία ανάπτυξης του συστήματος αξιολόγησης των επιπτώσεων των υδρομορφολογικών τροποποιήσεων στη σύνθεση και αφθονία των υδρόβιων και των παρόχθιων ειδών και η δημιουργία του Πολυμετρικού Δείκτη Μακροφύτων. Τα δεδομένα συλλέχθηκαν από συνολικά 32 θέσεις δειγματοληψίας οι οποίες επιλέχθηκαν με κριτήρια 1) την κάλυψη ευρείας διαβάθμισης χρήσεων γης, 2) την επιλογή περισσοτέρων του ενός τμημάτων με παρόμοια γεωμορφολογικά χαρακτηριστικά, 3) τη σταθερή απόσταση μεταξύ των θέσεων δειγματοληψίας, 4) την ομοιογένεια των τμημάτων και τέλος 5) την προσβασιμότητα στα σημεία δειγματοληψίας καθ’ όλη τη διάρκεια της παρακολούθησης. Με βάση τα πιο πάνω κριτήρια επιλέχθηκαν 15 θέσεις δειγματοληψίας στη λεκάνη απορροής του ποταμού Αχέροντα [11 Αχέροντας (A1-8 & A11-13), 1 Κωκυτός (A9), 1 Βουβό Ρέμα (A15), 2 αρδευτικά κανάλια (A10 & A14)] και 17 Θέσεις Δειγματοληψίας στη λεκάνη απορροής του ποταμού Λούρου (S1-17). Η περιοχή αξιολόγησης περιλαμβάνει ένα ομοιογενές τμήμα ποταμού μήκους 100 m, το οποίο χωρίστηκε σε τρία επί μέρους τμήματα: α) το τμήμα της κοίτης το οποίο καλύπτεται με νερό, β) τα κράσπεδα, δηλαδή το ενεργό τμήμα της κοίτης γ) την παρόχθια-δασική ζώνη. Για τη συλλογή και την αξιολόγηση της υδρόβιας και παρόχθιας βλάστησης πραγματοποιήθηκαν εποχικές δειγματοληψίες κατά τη διάρκεια των βλαστητικών περιόδων των ετών 2005-2007 και η αφθονία ειδών καταγράφηκε με την 5-βάθμια κλίμακα DAFOR (5: κυριαρχία και 1: απουσία). Στο πεδίο μετρήθηκαν επίσης οι φυσικοχημικές παράμετροι του νερού (pH, διαλυμένο οξυγόνο, θερμοκρασία, αγωγιμότητα, ταχύτητα νερού και μέσο βάθος νερού) και συλλέχθηκαν δείγματα επιφανειακού νερού για χημικές αναλύσεις θρεπτικών αλάτων αζώτου (ΝΟ3-Ν, ΝΟ2-Ν, ΝΗ4-Ν) και φωσφόρου (PO4-P & TP), Chl-a και αλκαλικότητας. Επίσης καταγράφηκαν στο πεδίο και υπολογίστηκαν στο εργαστήριο υδρογεωμορφολογικά στοιχεία και δεδομένα τοπίου τα οποία αφορούν τόσο την περιοχή αξιολόγησης όσο και όλη τη λεκάνη απορροής. Για τη στατιστική επεξεργασία των δεδομένων χρησιμοποιήθηκαν 1) Ιεραρχική Ανάλυση Συστάδων για βιοτική τυπολογία των υδρόβιων μακροφύτων κατά μήκος των ποταμών και για τον προσδιορισμό της δομής της παρόχθιας βλάστησης, 2) Ανάλυση Ειδών Δεικτών (ISA), για την περιγραφή της ιεραρχικής δομής της κάθε ομάδας και για τη διάκριση των σημαντικών Ειδών-Δεικτών (IndSps), και 3) Ταξιθέτηση όπου χρησιμοποιήθηκαν τόσο έμμεσες όσο και άμεσες αναλύσεις διαβάθμισης. Στις έμμεσες αναλύσεις διαβάθμισης χρησιμοποιήθηκαν α) Ανάλυση Κύριων Συνιστωσών (PCA), για τον προσδιορισμό των Γεωμορφολογικών Ενοτήτων και στον Καθορισμό της κλίμακας πιέσεων και β) Βελτιωμένη Ανάλυση Αντιστοιχιών (DCA), για τη χωρική κατανομή της αφθονίας των ειδών και τον έλεγχος των εποχικών και διαχρονικών διακυμάνσεων των κοινοτήτων αναφοράς. Ως άμεσες αναλύσεις διαβάθμισης χρησιμοποιήθηκαν α) Ανάλυση Πλεονασμού (RDA), για συσχέτιση των φυσικοχημικών χαρακτηριστικών του νερού με τα είδη δείκτες και β) Ανάλυση Κανονικών Αντιστοιχιών (CCA), για συσχέτιση των γεωμορφολογικών παραμέτρων με τα είδη-δείκτες και τον καθορισμό κύριων μεταβλητών υποβάθμισης της παρόχθιας ζώνης. Τα αποτελέσματα έδειξαν ότι κατά μήκος των δύο λεκανών απορροής διακρίνονται έξι Ομάδες Βλάστησης με παρόμοιο περιβαλλοντικό πρότυπο (πηγές-εκβολές). Στις ορεινές περιοχές και των δύο λεκανών απορροής (Αχέροντα και Λούρου) κυριαρχούν τα είδη Pteridium aquilinum, είδη βρυόφυτων και είδη του γένους Carex, C. acuta για τον ποταμό Αχέροντα και C. pendula για τον ποταμό Λούρο. Στο μέσο ρου των ποταμών διακρίθηκαν 4 διαφορετικές ομάδες βλάστησης. Ο διαφορετικός βαθμός ανθρωπογενούς τροποποίησης των εκβολών στις δύο λεκάνες απορροής αντανακλά και στη σύνθεση των φυτοκοινοτήτων όπου στις εκβολές του ποταμού Αχέροντα κυριαρχούν χλωροφύκη και το ανθεκτικό είδος Potamogeton pectinatus ενώ στον ποταμό Λούρο οι εκβολές χαρακτηρίζονται από την απουσία χλωροφυκών και την κυριαρχία του είδους Potamogeton nodosus. Οι σημαντικότεροι φυσικοχημικοί παράγοντες οι οποίοι επηρεάζουν την κατανομή των υδρόβιων μακροφύτων κατά μήκος των λεκανών απορροής της περιοχής μελέτης είναι: το pH, η αγωγιμότητα, η θερμοκρασία νερού, η μέση ταχύτητα νερού, οι συγκεντρώσεις των αλάτων αζώτου (ΝΟ3-Ν, ΝΗ4-Ν, ΝΟ2-Ν) και ορθοφωσφορικών (PO4-P) και Chl-a. Ενώ οι σημαντικότεροι γεωμορφολογικοί παράγοντες είναι: το υψόμετρο, το υπόστρωμα κοίτης, το πλάτος της κοίτης, η σκίαση της κοίτης, ο τύπος ενδιαιτήματος και το βάθος του νερού. Η διερεύνηση της δομής της παρόχθιας ζώνης έδειξε την ύπαρξη 4 διαφορετικών ομάδων παρόχθιας βλάστησης. Οι ορεινές περιοχές και άνω μέσος ρους και των δύο λεκανών απορροής χαρακτηρίζεται από την κυριαρχία των ειδών Platanus orientalis και Quercus coccifera. Οι βασικές τροποποιήσεις που δέχονται οι περιοχές αυτές αφορούν μεταβολές σε τοπικό επίπεδο γεγονός που επιβεβαιώνεται από τις υψηλές τιμές δείκτη QBR. Οι πεδινές περιοχές χαρακτηρίζονται από την κυριαρχία των ειδών Salix alba και Populus alba. Οι σημαντικότερες πιέσεις που δέχεται το πεδινό τμήμα των ποταμών αφορούν τις γεωργικές δραστηριότητες, τη δημιουργία τεχνικών αναχωμάτων, την ενίσχυση της όχθης, τις αμμοχαλικοληψίες, τη διευθέτηση και την ευθυγράμμιση της όχθης. Το είδος Phragmites australis χαρακτηρίζει τις εκβολές των ποταμών, ενώ σημαντική ήταν η αφθονία των ειδών Arundo donax και του εισαγόμενου είδους Eucalyptus camaldulensis. Σύμφωνα με τα αποτελέσματα η αφθονία των ειδών ήταν χαμηλή σε όλες τις Ομάδες Βλάστησης. Εφαρμόστηκαν επίσης οι δείκτες: QBR ο οποίος αποτελεί μέτρο αξιολόγησης της ποιότητας της παρόχθιας ζώνης, HQA όπου αποτελεί δείκτη αξιολόγησης της οικολογικής ποιότητας του ποτάμιου ενδιαιτήματος και HMS ο οποίος είναι δείκτης ανθρωπογενούς τροποποίησης του ενδιαιτήματος. Τα αποτελέσματα από την εφαρμογή των πιο πάνω δεικτών έδειξαν ότι η οικολογική ακεραιότητα παρόχθιας ζώνης αυξάνει τη συνολική οικολογική ποιότητα. Σύμφωνα με τις υδρογεωμορφολογικές μεταβλητές, οι οποίες εξετάστηκαν, οι θέσεις δειγματοληψίας ομαδοποιηθήκαν σε τρεις Γεωμορφολογικές Ενότητες οι οποίες αντιστοιχούν στο Ορεινό, Πεδινό και Εκβολικό Τμήμα των ποταμών. Σε κάθε Γεωμορφολογική Ενότητα πραγματοποιήθηκε ανάλυση πιέσεων και διακρίθηκαν οι σταθμοί αναφοράς οι οποίοι για το ορεινό τμήμα ήταν 7, στο πεδινό 3 ενώ στο εκβολικό τμήμα μόνο 2 σταθμοί χαρακτηρίστηκαν ως περιοχές αναφοράς. Σε κάθε Γεωμορφολογική Ενότητα διερευνήθηκαν οι εποχικές και διαχρονικές μεταβολές στη σύνθεση των κοινοτήτων αναφοράς και προσδιορίστηκε δομή τους. Τα αποτελέσματα έδειξαν, ότι η σύνθεση των κοινοτήτων αναφοράς στο πεδινό τμήμα των ποταμών φαίνεται να παραμένουν σταθερές στις φυσικές διακυμάνσεις. Από την άλλη, οι μικρές διαφορές οι οποίες καταγράφηκαν στο ορεινό και εκβολικό τμήμα των ποταμών οφείλονται κυρίως στην όψιμη Άνοιξη και στις υψηλές θερμοκρασίες που επικρατούν κατά τους καλοκαιρινούς μήνες και εντοπίζονται στο μειωμένο αριθμό των βρυοφύτων και πτεριδοφύτων αντίστοιχα. Τέλος σύμφωνα τα αποτελέσματα η περίοδος διεξαγωγής των δειγματοληψιών προσδιορίζεται ανάμεσα στο χρονικό διάστημα μεταξύ τέλος Απριλίου και τέλος Σεπτεμβρίου αφού σε αυτό το χρονικό διάστημα οποιαδήποτε επίσκεψη στο πεδίο αναμένεται να δώσει την ίδια σύνθεση των κοινοτήτων αναφοράς. Διερευνήθηκαν, στο μεγαλύτερο δυνατό βαθμό, όλες οι πιθανές παράμετροι και πιέσεις, οι οποίες επηρεάζουν τη σύνθεση και την κατανομή υδρόβιων μακροφύτων κατά μήκος των λεκανών απορροής. Οι σημαντικότερες πιέσεις που δέχεται η περιοχή μελέτης επηρεάζουν κυρίως τα υδρομορφολογικά χαρακτηριστικά του οικοσυστήματος. Ως πιο αξιόπιστος και ολιστικός τρόπος αξιολόγησης της οικολογικής κατάστασης της περιοχής μελέτης επιλέχθηκε η Πολυμετρική προσέγγιση. Σαν πίεση επιλέχθηκε η υδρομορφολογική τροποποίηση. Συνολικά, διερευνήθηκαν 86 υποψήφιες μετρικές οι οποίες ανήκουν σε 5 κατηγορίες: 1) Αφθονίας/Ποικιλότητας, 2) Τροφικής κατάστασης, 3) Σύνθεσης φυτικών κοινοτήτων, 4) Ποιότητας Δομής της παρόχθιας ζώνης και 5) Ευαισθησίας/Ανοχής, οι οποίες προέρχονται από τις βιοκοινότητες του υγρού δίαυλου, της ενεργής κοίτης και της όχθης. Ο καθορισμός της κλίμακας πιέσεων πραγματοποιήθηκε με τη χρήση της Ανάλυσης Κύριων Συνιστωσών (PCA) με 36 υδρομορφολογικές μεταβλητές υποβάθμισης σε 2 χωρικά επίπεδα: Μακροκλίμακας και Μικροκλίμακας. Στον τελικό Πολυμετρικό δείκτη συμπεριλήφθηκαν μόνο οι μετρικές οι οποίες ικανοποιούσαν συγκεκριμένα κριτήρια. Τα κριτήρια αυτά αφορούσαν: την εκπλήρωση του κριτηρίου από την εφαρμογή των θηκογραμμάτων με απολήξεις (δηλαδή εξαιρούνται οι μετρικές οι οποίες έχουν στενό εύρος τιμών, πολλές ακραίες τιμές και πολλές απόμακρες παρατηρήσεις), την αποφυγή αλληλεπικαλυπτόμενων πληροφοριών (Spearman ǀrǀ>0,800) και την υψηλή συσχέτιση με τις κλίμακες πιέσεων (Spearman ǀrǀ>0,500). Συνολικά από τις 86 υποψήφιες μετρικές οι 6 θεωρήθηκαν ως κεντρικές μετρικές αφού ικανοποίησαν όλα τα πιο πάνω κριτήρια. Οι κεντρικές μετρικές είναι: 1) Δείκτης IBMR, 2) Δείκτης QBR, 3) Αριθμός Βρυοφυτικών taxa, 4) % Είδη Αναφοράς, 5) % Νιτρόφιλα είδη και 6) % Ελοφυτικά είδη (Phe_herbids). Ο Πολυμετρικός Δείκτης Μακροφύτων (Multimetric Macrophyte Index-MMI) είναι ο αριθμητικός μέσος των 6 κανονικοποιημένων «κεντρικών» μετρικών. Κανονικοποίηση καλείται η προσαρμογή του εύρους τιμών της κάθε μετρικής στο ενδεικτικό όριο από 0 μέχρι 1. Σημαντικό σημείο στην κανονικοποίηση των μετρικών είναι ο καθορισμός του ανώτερου (upper anchor) και κατώτερου ορίου (lower anchor) της κάθε «κεντρικής» μετρικής. Το ανώτερο και το κατώτερο όριο δείχνουν το ενδεικτικό εύρος της κάθε μετρικής όπου το ανώτερο όριο (anchor) αντιστοιχεί στην τιμή της μετρικής κάτω από τις συνθήκες αναφοράς. Στην παρούσα εργασία για το ανώτερο όριο κάθε μετρικής επιλέχθηκε το 75ο εκατοστημόριο (percentile) των μη διαταραγμένων περιοχών και για το κατώτερο όριο το 5ο εκατοστημόριο (percentile) των διαταραγμένων περιοχών. Για την αξιολόγηση της οικολογικής ποιότητας, των θέσεων δειγματοληψίας, με βάση τον Πολυμετρικό Δείκτη Μακροφύτων, απαιτείται ο καθορισμός των ορίων μεταξύ των 5 ποιοτικών κλάσεων όπως απαιτεί η Οδηγία Πλαίσιο για τα Ύδατα 2000/60/ΕΕ. Τα όρια του δείκτη καθορίστηκαν υπολογίζοντας αρχικά το όριο μεταξύ της «Υψηλής»/«Καλής» οικολογικής κατάστασης το οποίο ορίστηκε ως το 25o εκατοστημόριο μη διαταραγμένων περιοχών (0,623). Το υπόλοιπο εύρος τιμών χωρίστηκε σε τέσσερις ίσες κλάσεις. Τα αποτελέσματα έδειξαν, ότι ο ΜΜΙ δίνει πολύ καλή ένδειξη της οικολογικής κατάστασης των μεσαίου μεγέθους πεδινών ποταμών της Δυτικής Ελλάδας (RM-2). Σύμφωνα με τα αποτελέσματα το 29,6% των θέσεων δειγματοληψίας (8 θέσεις) ταξινομήθηκαν στην Υψηλή οικολογική κατάσταση, το 4% (14 θέσεις) στην Καλή οικολογική κατάσταση, το 22,3% (6 θέσεις) στην Μέτρια, το 29,6% (8 θέσεις) στην Φτωχή και μόνο το 3,7% (1 θέση) χαρακτηρίστηκε ως Κακής Οικολογικής Ποιότητας. Η παρούσα Διδακτορική Διατριβή, αποτελεί µια πρώτη προσπάθεια στον Ελληνικό χώρο για δημιουργία ενός ολοκληρωμένου συστήματος παρακολούθησης της οικολογικής ποιότητας των ρεόντων υδάτων με χρήση των υδρόβιων μακροφύτων ως βιολογικών ποιοτικών στοιχείων. Η μεθοδολογία αναπτύχθηκε και εφαρμόστηκε πιλοτικά σε δύο λεκάνες απορροής στα μεσαίου μεγέθους πεδινά ποτάμια της Ηπείρου Αχέροντα και Λούρου ακολουθώντας πιστά τις απαιτήσεις και τις κατευθυντήριες γραμμές της Ευρωπαϊκής Οδηγίας Πλαίσιο για τα Ύδατα 2000/60/ΕΕ. Επίσης το σύστημα αξιολόγησης το οποίο προτείνεται αναπτύχθηκε με σκοπό την εφαρμογή του σε όλα τα παρόμοιου τύπου ποτάμια της Ελλάδας αφού τόσο ο κατάλογος με τις υποψήφιες μετρικές όσο και ο ίδιος ο πολυμετρικός δείκτης μπορεί να ελεγχθεί και σε άλλους τύπους ποταμών της Ελλάδας (RM-1, RM-3, RM-4 & RM-5). Τέλος, τα αποτελέσματα που προκύπτουν συμβάλλουν στην ορθολογικότερη διαχείριση και ανάδειξη των ποτάμιων ενδιαιτημάτων και στην εφαρμογή της περιβαλλοντικής πολιτικής του νερού στην Ελλάδα. / The main objective of the present thesis was the ecological assessment of two river basins, Acheron and Louros; based on aquatic plant communities, water quality and hydromorphological characteristics, as well as, the development of a methodology for collecting, analyzing and assessing field data, specific adapted to Greek conditions. The specific objectives of the doctoral thesis include: a) the investigation of abiotic parameters influencing the distribution of aquatic macrophytes along the two river basins (Chapter A); b) the investigation of riparian zone structure and the assessment of “key” environmental gradient and human intervention (Chapter B); c) abiotic typology for reducing the spatial variability, monitoring the temporal and seasonal variation in of aquatic macrophytes distribution, and determination of reference communities in each geomorphological unit of the riverine ecosystem (Chapter C), and d) the development of the Macrophyte Multimetric Index (MMI) which is described step by step in Chapter D. Data were collected from 32 sampling sites, which were chosen according to the following criteria: i) covering a wide gradient of land used i.e. from natural to artificial; ii) selection of more than one site with similar geomorphological characteristics; iii) the constant distance between sampling sites; iv) the homogeneity of the sampling sites, and v) the accessibility to the sampling points throughout the duration of monitoring. Based on the above criteria, 15 sites were selected along Acheron river basin [11, Acheron river (A1-8 & A11-13); 1, Cocytos (A9); 1, Vouvo Rema (A15); 2, irrigation canals (A10 & A14)]. Additionally, 17 sampling sites were selected along Louros river (S1-S15). The survey area was subdivided into 3 zones, a) the wetted part of the channel, b) the marginal-active channel and c) the riparian woodland plot. The survey area length was standardized at 100 m according to the widely accepted methods [e.g. Mean Trophic Rank, (MTR); Riparian Forest Quality, (QBR)]. On the other hand, the width of each plot includes the area between, the end of the active channel and the riparian woodland. The field surveys were conducted during the vegetation periods (April to September) of the years 2005 to 2007. The coverage of each macrophyte species was visually estimated using DAFOR 5-point scale (1: Rare, 2: Occasional, 3: Frequent, 4: Abundant and 5: Dominant). Also, water physicochemical parameters such as temperature, DO, pH, conductivity, were measured in situ using portable equipment (WTW340i/SET). Additionally, surface water samples were collected for determination of nutrients such as nitrate and nitrite nitrogen, total nitrogen, ammonium, phosphorus nutrients (soluble reactive phosphorus and total phosphorus), Chl-a, and alkalinity (HCO-3, CO3=). Nutrient samples were collected and analyzed according to APHA standard analytical method (APHA, 1989). For the statistical processing of the data were used: 1) Hierarchical cluster analysis (Bray-Curtis), for the biotic typology of macrophyte data along river basins and to determine the structure of the riparian vegetation; 2) Indicator Species Analysis, was used to describe the hierarchical structure of each group to distinguish the indicator species (Ind_Sps) for each vegetation group; 3) Ordination, which were used both Indirect and Direct gradient analyses. Indirect gradient analyzes were used: a) Principal Component Analysis (PCA), to identify Geomorphological Units and to determining the pressure gradients; and b) Detrended Correspondence Analysis (DCA), for researching the spatial distribution of species abundance, and for seasonal and inter-annual variability of the reference communities. For direct gradient analyzes were used: a) Redundancy Analysis (RDA), for correlation between, water physicochemical parameters and Indicator species; and b) Canonical Correspondence Analysis (CCA), for correlation between geomorphological characteristics and indicator species, as well as, to determine the key variables best explain the degradation of the riparian zone. The results showed that along the two river basins, six vegetation groups can be distinguished, with similar environmental gradient pattern (springs-estuaries). The dominant species for the upper part of Acheron and Louros river basins were: Pteridium aquilinum, bryophyte taxa and Carex species (C. acuta and C. pendula respectively). Moreover, four different vegetation groups were characterized the middle part of both river basins. The different degree of anthropogenic alteration of river estuaries (Acheron and Louros), reflects in the composition of the plant communities. The estuaries of Acheron were characterized by the dominant of green algae and the tolerant species Potamogeton pectinatus, while the estuaries of Louros river was characterized by the absence of green algae and the dominance of Potamogeton nodosus. The most important physicochemical variables that significantly affect the distribution of aquatic macrophytes along the river basins were: pH, conductivity, water temperature, and mean water velocity, concentrations of nitrogen nutrients (ΝΟ3-Ν, ΝΗ4-Ν, ΝΟ2-Ν) and orthophosphate (PO4-P), as well as, Chl-a. Whereas, the most important geomorphological factors were: altitude, bed substrate, channel width, channel shading, habitat type, water depth. Hierarchical cluster analysis distinguished five vegetation groups of the riparian zone of the study area. The following groups were indentified and characterized by the dominant riparian species. The upper reaches were characterized by the Vegetation Group Ia: Platanus orientalis and Ib: Quercus coccifera-P. orientalis; the middle reaches by II: Salix alba and Populus alba; and lowland areas until estuaries by III: Phragmites australis. Vegetation Group IV was characterized by the dominant of non native species Eucalyptus camaldulensis and the giant reed Arundo donax. According to the results, species abundance was low in all Vegetation Groups. Also, the applied indices Riparian quality assessment (QBR), Habitat Quality Assessment (HQA) and Habitat Modification Score (HMS) revealed that the ecological integrity of the riparian zone increases the overall ecological quality of the riparian ecosystem. According to the hydromorphological characteristics, the sampling sites were grouped into three Geomorphological Units: Upper –Middle reaches-Estuaries. In each Geomorphological Unit (GU) a pressure gradient analysis was performed, and the reference sites were identified. For GU I the number of reference sites was 7, for GU II 3 reference sites were identified, while, for the estuaries the number of the reference sites were only 2. Also in each GU the seasonal and inter annual changes in reference communities, were investigated, and the structure of the reference community was determined. The results showed that the composition of the reference communities in lowland rivers appears to remain constant in the physical fluctuations. On the other hand, the slight differences which were recorded, in the GU I, during spring and summer sampling, referred to the reduction of bryophytes. This reduction might be cause due to the late spring (May), at the upper part of Louros river. Also, differences were recorded between autumn and spring samplings, in the GU III (estuaries). Those differences referred to the reduction of pteridophytes, maybe due to the high temperatures that prevail during the summer months. Finally, the sampling period could be set between late April and late September, since, during this period, any field visit will give the same composition of the reference communities. We investigated, to the greatest possible degree, all the potential parameters and pressures, which could influence the composition and distribution of aquatic macrophytes along the river basins. The most significant effect, from the current pressures, in the studied area, is the alteration of the hydromorphological characteristics of the ecosystem. The Multimetric approach was chosen, as the most holistic and reliable evaluation method of the ecological status of the study area. A preliminary list of potential plant metrics was compiled from a review of the literature, and in situ observations of plant community patterns. The metrics were grouped into five categories, so that each one representing a different ecological aspect of aquatic and riparian plant communities: 1) Richness/Diversity, 2) Trophic status, 3) Composition, 4) Riparian Integrity, and 5) Sensitivity/Tolerance. A total of 86 metrics were tested, of which 7 belonged to the category of "Abundance/Diversity", 4 to the category of "Trophic” status, 46 metric referred to “Composition” of plant communities, 11 referred to "Riparian Integrity”, and finally, 18 belonged to “Sensitivity/Tolerance” category. The estimation of the pressure gradient was performed using Principal Component Analyses (PCAs), with 36 hydromorphological degradation variables in 2 spatial scales: macroscale and microscale. Candidate metrics, which can be identified as robust and most informative, are scrutinized further, in the process of selecting core metrics. To be selected as a core metric the following aspects have to be considered: 1) core metrics should cover different metric types (see above); 2) metrics should not give redundant information. Inter-correlation tests between candidate metrics were carried out to detect redundant metrics (threshold value Spearman’s r<0.800). In case of redundancy we further investigate: the correlation of each metric with stress gradient (threshold value Spearman’s r<0.05); the correlation of each of the pair of metrics with the other metrics in order to finally omit the one that showed the higher overall mean correlation; and how well they separate stressed from unstressed sampling sites (graphical analysis of box-whisker plots). The final index includes 6 metrics out of 86 candidated metrics. The core metrics are: 1) IBMR, 2) QBR, 3) Number of Bryophyte, 4) % Reference Species, 5) % Nitrophilous taxa and 6) % Helophyte taxa (Phe_herbids). The different numerical scales of each core metric (e.g. abundance class, number of individuals) were normalized to unitless scores between 0 and 1. The upper and lower anchors mark the indicative range of a metric. The upper anchor corresponds to the upper limit of the metric’s value under reference conditions, and it was set as the 75th of the unstressed sites. The lower anchor corresponds to the lower limit of the metric’s value under the worst attainable conditions and it was set as 5th percentile of stressed sites. The multimetric index was calculated as the arithmetic mean of the normalized metrics (Böhmer et al., 2004). The final Multimetric Index provides a score that represents the overall relationship between the combined values of the biological parameters observed for a given site and the expected value under reference conditions. This score is – as for single metrics – expressed as a numerical value between zero and one. This range can be subdivided into any number of categories corresponding to various levels of impairment. To determine the boundaries of Multimetric Index, the 25th percentile of the unstressed sites (0,623) was set as the boundary for the high/good ecological class. We propose quality classes with equal ranges, to provide five ordinal rating categories for assessment of impairment in accordance with the demands of the WFD. The application of Macrophyte Multimetric Index (MMI) in the medium lowland rivers of Greece led to the ecological classification in five quality classes. The results indicated that the 29.6% of the sampling sites (8 sites) were classified in High ecological status, 4% (4 sites) in Good ecological status; the 22.3% (6 sites) in Moderate, 29.6% (8 sites) in the Poor and only 3.7% (1 site) was characterized as Bad ecological quality. The current doctoral thesis was the first attempt in the Greece, for establishing an integrated monitoring system of ecological quality of running water ecosystems, using aquatic macrophytes as biological quality element. The methodology developed, was pilot implemented in two river basins, Acheron and Louros, in Epirus, following the requirements and guidelines of the European Water Framework Directive, 2000/60/EE. Also, the evaluation system was developed to be proposed for implementation at all similar river types of Greece, since both the list of candidate metrics and the Multimetric Index itself, can be tested in other types of Greek rivers (RM-1, RM-3, RM-4 & RM-5). Finally, the results, will contribute to the sustainable management and conservation of riverine ecosystems, as well as, to the implementation of the water environmental policy in Greece.