Brian Armitage | Universidad Autónoma de Chiriqui (original) (raw)
Papers by Brian Armitage
Wetlands, 2002
Interest by land-management and regulatory agencies in using biological indicators to detect wetl... more Interest by land-management and regulatory agencies in using biological indicators to detect wetland degradation, coupled with ongoing use of this approach to assess water quality in streams, led to the desire to develop and evaluate an Index of Biotic Integrity (IBI) for wetlands that could be used to categorize the level of degradation. We undertook this challenge with data from coastal wetlands of the Great Lakes, which have been degraded by a variety of human disturbances. We studied six barrier beach wetlands in western Lake Superior, six drowned-river-mouth wetlands along the eastern shore of Lake Michigan, and six open shoreline wetlands in Saginaw Bay of Lake Huron. Plant, fish, and invertebrate communities were sampled in each wetland. The resulting data were assessed in various forms against gradients of human disturbance to identify potential metrics that could be used in IBI development. Our results suggested that the metrics proposed as potential components of an IBI for barrier beach wetlands of Lake Superior held promise. The metrics for Lake Michigan drowned-river-mouth wetlands were inconsistent in identifying gradients of disturbance; those for Lake Huron open embayment wetlands were yet more inconsistent. Despite the potential displayed by the Lake Superior results within the year sampled, we concluded that an IBI for use in Great Lakes wetlands would not be valid unless separate scoring ranges were derived for each of several sequences of water-level histories. Variability in lake levels from year to year can produce variability in data and affect the reproducibility of data collected, primarily due to extreme changes in plant communities and the faunal habitat they provide. Substantially different results could be obtained in the same wetland in different years as a result of the response to lake-level change, with no change in the level of human disturbance. Additional problems included limited numbers of comparable sites, potential lack of undisturbed reference sites, and variable effects of different disturbance types. We also evaluated our conclusions with respect to hydrologic variability and other major natural disturbances affecting wetlands in other regions. We concluded that after segregation of wetland types by geographic, geomorphic, and hydrologic features, a functional IBI may be possible for wetlands with relatively stable hydrology. However, an IBI for wetlands with unpredictable yet recurring influences of climate-induced, long-term high water periods, droughts, or drought-related fires or weather-related catastrophic floods or high Wilcox et al., EVALUATION OF WETLAND IBI METRICS 589 winds (hurricanes) would also require differing scales of measurement for years that differ in the length of time since the last major natural disturbance. A site-specific, detailed ecological analysis of biological indicators may indeed be of value in determining the quality or status of wetlands, but we recommend that IBI scores not be used unless the scoring ranges are calibrated for the specific hydrologic history pre-dating any sampling year.
Fringing wetlands of the Laurentian Great Lakes are subject to natural processes, such as water-l... more Fringing wetlands of the Laurentian Great Lakes are subject to natural processes, such as water-level fluctuation and wave-induced erosion, and to human alterations. In order to evaluate the quality of these wetlands over space and time, biological communities are often examined. Ideally, the groups of organisms selected for these evaluations should be resident in the wetlands themselves. Fish are often sampled, but many species are not truly resident, visiting wetlands on an occasional basis to feed or on a seasonal basis to breed. Aquatic vascular plants are perhaps the most common group selected for evaluation. However, in some cases, aquatic plants give a false impression by providing photosynthetic capabilities and structural infrastructure but having greatly diminished herbivore and carnivore communities.
In the Republic of Panama, the family Hydroptilidae (Insecta: Trichoptera) is currently represent... more In the Republic of Panama, the family Hydroptilidae (Insecta: Trichoptera) is currently represented
by 82 species distributed among 14 genera. In this publication we provide descriptions and illustrations for
10 new species of hydroptilids in the subfamily Hydroptilinae: Tribe Leucotrichiini—Zumatrichia teribe and
Z. zegla; Tribe Neotrichiini—Neotrichia pamelae and N. parabullata; and, Tribe Ochrotrichiini—Metrichia
nowaczyki, M. sencilla, Nothotrichia panama, Ochrotrichia abrelata, O. nimmoi, and O. pulgara. The genus
Nothotrichia is recorded from Panama for the first time.
Interest by land-management and regulatory agencies in using biological indicators to detect wetl... more Interest by land-management and regulatory agencies in using biological indicators to detect wetland degradation, coupled with ongoing use of this approach to assess water quality in streams, led to the desire to develop and evaluate an Index of Biotic Integrity (IBI) for wetlands that could be used to categorize the level of degradation. We undertook this challenge with data from coastal wetlands of the Great Lakes, which have been degraded by a variety of human disturbances. We studied six barrier beach wetlands in western Lake Superior, six drowned-river-mouth wetlands along the eastern shore of Lake Michigan, and six open shoreline wetlands in Saginaw Bay of Lake Huron. Plant, fish, and invertebrate communities were sampled in each wetland. The resulting data were assessed in various forms against gradients of human disturbance to identify potential metrics that could be used in IBI development. Our results suggested that the metrics proposed as potential components of an IBI for barrier beach wetlands of Lake Superior held promise. The metrics for Lake Michigan drowned-river-mouth wetlands were inconsistent in identifying gradients of disturbance; those for Lake Huron open embayment wetlands were yet more inconsistent. Despite the potential displayed by the Lake Superior results within the year sampled, we concluded that an IBI for use in Great Lakes wetlands would not be valid unless separate scoring ranges were derived for each of several sequences of water-level histories. Variability in lake levels from year to year can produce variability in data and affect the reproducibility of data collected, primarily due to extreme changes in plant communities and the faunal habitat they provide. Substantially different results could be obtained in the same wetland in different years as a result of the response to lake-level change, with no change in the level of human disturbance. Additional problems included limited numbers of comparable sites, potential lack of undisturbed reference sites, and variable effects of different disturbance types. We also evaluated our conclusions with respect to hydrologic variability and other major natural disturbances affecting wetlands in other regions. We concluded that after segregation of wetland types by geographic, geomorphic, and hydrologic features, a functional IBI may be possible for wetlands with relatively stable hydrology. However, an IBI for wetlands with unpredictable yet recurring influences of climate-induced, long-term high water periods, droughts, or drought-related fires or weather-related catastrophic floods or high Wilcox et al., EVALUATION OF WETLAND IBI METRICS 589 winds (hurricanes) would also require differing scales of measurement for years that differ in the length of time since the last major natural disturbance. A site-specific, detailed ecological analysis of biological indicators may indeed be of value in determining the quality or status of wetlands, but we recommend that IBI scores not be used unless the scoring ranges are calibrated for the specific hydrologic history pre-dating any sampling year.
Journal of Great Lakes Research, 1991
Abundance and distribution patterns of the caddisflies of the St. Clair-Detroit River system were... more Abundance and distribution patterns of the caddisflies of the St. Clair-Detroit River system were investigated in 1983-84. Collections of both adults and larvae yielded 70 species representing 34 genera and 12 families. Leptoceridae and Hydroptilidae were the most common families and Ceraclea the most common genus in number of species. This study adds 21 species to the Michigan record. The hydropsychids Cheumatopsyche (81, 63, 105 m-2 ; log-transformed values for mean and lower and upper 95% C.L.) and Hydropsyche (70, 57, were the most abundant genera collected as larvae in the St. Clair and Detroit rivers, while Oecetis (41, 35, was the most abundant in Lake St. Clair. Larval densities of caddisflies in the Detroit River were about twice those in the St. Clair River, but the number of genera collected in each river was about equal (22 vs. 23). Larval abundances were higher in October than May because most genera had substantial overwinter population declines. Low densities and species richness in some areas of the St. Clair-Detroit River system may reflect in part continued water quality problems, but community structure has markedly improved and representation of pollution-sensitive organisms has increased over a 12-15 year period. 1983-84. Collections of both adults and larvae yielded 70 species representing 34 genera and 12 families. Leptoceridae and Hydroptilidae were the most common families and Ceraclea the most common genus in number of species. This study adds 21 species to the Michigan record. The hydropsychids Cheumatopsyche (81, 63, 105 m-2 ; log-transformed values for mean and lower and upper 95% C.L.) and Hydropsyche (70, 57, were the most abundant genera collected as larvae in the St. Clair and Detroit rivers, while Oecetis (41, 35, was the most abundant in Lake St. Clair. Larval densities of caddisflies in the Detroit River were about twice those in the St. Clair River, but the number of genera collected in each river was about equal (22 vs. 23). Larval abundances were higher in October than May because most genera had substantial overwinter population declines. Low densities and species richness in some areas of the St. Clair-Detroit River system may reflect in part continued water quality problems, but community structure has markedly improved and representation of pollution-sensitive organisms has increased over a 12-15 year period.
Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published... more Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published on any non-marine arthropod taxon. Manuscripts considered for publication include, but are not limited to, systematic or taxonomic studies, revisions, nomenclatural changes, faunal studies, book reviews, phylogenetic analyses, biological or behavioral studies, etc. Insecta Mundi is widely distributed, and referenced or abstracted by several sources including the Zoological Record, CAB Abstracts, etc.
Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published... more Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published on any non-marine arthropod. Topics considered for publication include systematics, taxonomy, nomenclature, checklists, faunal works, and natural history. Insecta Mundi will not consider works in the applied sciences (i.e. medical entomology, pest control research, etc.), and no longer publishes book reviews or editorials. Insecta Mundi publishes original research or discoveries in an inexpensive and timely manner, distributing them free via open access on the internet on the date of publication. Insecta Mundi is referenced or abstracted by several sources including the Zoological Record, CAB Abstracts, etc. Insecta Mundi is published irregularly throughout the year, with completed manuscripts assigned an individual number. Manuscripts must be peer reviewed prior to submission, after which they are reviewed by the editorial board to ensure quality. One author of each submitted manuscript must be a current member of the Center for Systematic Entomology. Manuscript preparation guidelines are availablr at the CSE website.
Wetlands, 2002
Interest by land-management and regulatory agencies in using biological indicators to detect wetl... more Interest by land-management and regulatory agencies in using biological indicators to detect wetland degradation, coupled with ongoing use of this approach to assess water quality in streams, led to the desire to develop and evaluate an Index of Biotic Integrity (IBI) for wetlands that could be used to categorize the level of degradation. We undertook this challenge with data from coastal wetlands of the Great Lakes, which have been degraded by a variety of human disturbances. We studied six barrier beach wetlands in western Lake Superior, six drowned-river-mouth wetlands along the eastern shore of Lake Michigan, and six open shoreline wetlands in Saginaw Bay of Lake Huron. Plant, fish, and invertebrate communities were sampled in each wetland. The resulting data were assessed in various forms against gradients of human disturbance to identify potential metrics that could be used in IBI development. Our results suggested that the metrics proposed as potential components of an IBI for barrier beach wetlands of Lake Superior held promise. The metrics for Lake Michigan drowned-river-mouth wetlands were inconsistent in identifying gradients of disturbance; those for Lake Huron open embayment wetlands were yet more inconsistent. Despite the potential displayed by the Lake Superior results within the year sampled, we concluded that an IBI for use in Great Lakes wetlands would not be valid unless separate scoring ranges were derived for each of several sequences of water-level histories. Variability in lake levels from year to year can produce variability in data and affect the reproducibility of data collected, primarily due to extreme changes in plant communities and the faunal habitat they provide. Substantially different results could be obtained in the same wetland in different years as a result of the response to lake-level change, with no change in the level of human disturbance. Additional problems included limited numbers of comparable sites, potential lack of undisturbed reference sites, and variable effects of different disturbance types. We also evaluated our conclusions with respect to hydrologic variability and other major natural disturbances affecting wetlands in other regions. We concluded that after segregation of wetland types by geographic, geomorphic, and hydrologic features, a functional IBI may be possible for wetlands with relatively stable hydrology. However, an IBI for wetlands with unpredictable yet recurring influences of climate-induced, long-term high water periods, droughts, or drought-related fires or weather-related catastrophic floods or high Wilcox et al., EVALUATION OF WETLAND IBI METRICS 589 winds (hurricanes) would also require differing scales of measurement for years that differ in the length of time since the last major natural disturbance. A site-specific, detailed ecological analysis of biological indicators may indeed be of value in determining the quality or status of wetlands, but we recommend that IBI scores not be used unless the scoring ranges are calibrated for the specific hydrologic history pre-dating any sampling year.
Fringing wetlands of the Laurentian Great Lakes are subject to natural processes, such as water-l... more Fringing wetlands of the Laurentian Great Lakes are subject to natural processes, such as water-level fluctuation and wave-induced erosion, and to human alterations. In order to evaluate the quality of these wetlands over space and time, biological communities are often examined. Ideally, the groups of organisms selected for these evaluations should be resident in the wetlands themselves. Fish are often sampled, but many species are not truly resident, visiting wetlands on an occasional basis to feed or on a seasonal basis to breed. Aquatic vascular plants are perhaps the most common group selected for evaluation. However, in some cases, aquatic plants give a false impression by providing photosynthetic capabilities and structural infrastructure but having greatly diminished herbivore and carnivore communities.
In the Republic of Panama, the family Hydroptilidae (Insecta: Trichoptera) is currently represent... more In the Republic of Panama, the family Hydroptilidae (Insecta: Trichoptera) is currently represented
by 82 species distributed among 14 genera. In this publication we provide descriptions and illustrations for
10 new species of hydroptilids in the subfamily Hydroptilinae: Tribe Leucotrichiini—Zumatrichia teribe and
Z. zegla; Tribe Neotrichiini—Neotrichia pamelae and N. parabullata; and, Tribe Ochrotrichiini—Metrichia
nowaczyki, M. sencilla, Nothotrichia panama, Ochrotrichia abrelata, O. nimmoi, and O. pulgara. The genus
Nothotrichia is recorded from Panama for the first time.
Interest by land-management and regulatory agencies in using biological indicators to detect wetl... more Interest by land-management and regulatory agencies in using biological indicators to detect wetland degradation, coupled with ongoing use of this approach to assess water quality in streams, led to the desire to develop and evaluate an Index of Biotic Integrity (IBI) for wetlands that could be used to categorize the level of degradation. We undertook this challenge with data from coastal wetlands of the Great Lakes, which have been degraded by a variety of human disturbances. We studied six barrier beach wetlands in western Lake Superior, six drowned-river-mouth wetlands along the eastern shore of Lake Michigan, and six open shoreline wetlands in Saginaw Bay of Lake Huron. Plant, fish, and invertebrate communities were sampled in each wetland. The resulting data were assessed in various forms against gradients of human disturbance to identify potential metrics that could be used in IBI development. Our results suggested that the metrics proposed as potential components of an IBI for barrier beach wetlands of Lake Superior held promise. The metrics for Lake Michigan drowned-river-mouth wetlands were inconsistent in identifying gradients of disturbance; those for Lake Huron open embayment wetlands were yet more inconsistent. Despite the potential displayed by the Lake Superior results within the year sampled, we concluded that an IBI for use in Great Lakes wetlands would not be valid unless separate scoring ranges were derived for each of several sequences of water-level histories. Variability in lake levels from year to year can produce variability in data and affect the reproducibility of data collected, primarily due to extreme changes in plant communities and the faunal habitat they provide. Substantially different results could be obtained in the same wetland in different years as a result of the response to lake-level change, with no change in the level of human disturbance. Additional problems included limited numbers of comparable sites, potential lack of undisturbed reference sites, and variable effects of different disturbance types. We also evaluated our conclusions with respect to hydrologic variability and other major natural disturbances affecting wetlands in other regions. We concluded that after segregation of wetland types by geographic, geomorphic, and hydrologic features, a functional IBI may be possible for wetlands with relatively stable hydrology. However, an IBI for wetlands with unpredictable yet recurring influences of climate-induced, long-term high water periods, droughts, or drought-related fires or weather-related catastrophic floods or high Wilcox et al., EVALUATION OF WETLAND IBI METRICS 589 winds (hurricanes) would also require differing scales of measurement for years that differ in the length of time since the last major natural disturbance. A site-specific, detailed ecological analysis of biological indicators may indeed be of value in determining the quality or status of wetlands, but we recommend that IBI scores not be used unless the scoring ranges are calibrated for the specific hydrologic history pre-dating any sampling year.
Journal of Great Lakes Research, 1991
Abundance and distribution patterns of the caddisflies of the St. Clair-Detroit River system were... more Abundance and distribution patterns of the caddisflies of the St. Clair-Detroit River system were investigated in 1983-84. Collections of both adults and larvae yielded 70 species representing 34 genera and 12 families. Leptoceridae and Hydroptilidae were the most common families and Ceraclea the most common genus in number of species. This study adds 21 species to the Michigan record. The hydropsychids Cheumatopsyche (81, 63, 105 m-2 ; log-transformed values for mean and lower and upper 95% C.L.) and Hydropsyche (70, 57, were the most abundant genera collected as larvae in the St. Clair and Detroit rivers, while Oecetis (41, 35, was the most abundant in Lake St. Clair. Larval densities of caddisflies in the Detroit River were about twice those in the St. Clair River, but the number of genera collected in each river was about equal (22 vs. 23). Larval abundances were higher in October than May because most genera had substantial overwinter population declines. Low densities and species richness in some areas of the St. Clair-Detroit River system may reflect in part continued water quality problems, but community structure has markedly improved and representation of pollution-sensitive organisms has increased over a 12-15 year period. 1983-84. Collections of both adults and larvae yielded 70 species representing 34 genera and 12 families. Leptoceridae and Hydroptilidae were the most common families and Ceraclea the most common genus in number of species. This study adds 21 species to the Michigan record. The hydropsychids Cheumatopsyche (81, 63, 105 m-2 ; log-transformed values for mean and lower and upper 95% C.L.) and Hydropsyche (70, 57, were the most abundant genera collected as larvae in the St. Clair and Detroit rivers, while Oecetis (41, 35, was the most abundant in Lake St. Clair. Larval densities of caddisflies in the Detroit River were about twice those in the St. Clair River, but the number of genera collected in each river was about equal (22 vs. 23). Larval abundances were higher in October than May because most genera had substantial overwinter population declines. Low densities and species richness in some areas of the St. Clair-Detroit River system may reflect in part continued water quality problems, but community structure has markedly improved and representation of pollution-sensitive organisms has increased over a 12-15 year period.
Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published... more Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published on any non-marine arthropod taxon. Manuscripts considered for publication include, but are not limited to, systematic or taxonomic studies, revisions, nomenclatural changes, faunal studies, book reviews, phylogenetic analyses, biological or behavioral studies, etc. Insecta Mundi is widely distributed, and referenced or abstracted by several sources including the Zoological Record, CAB Abstracts, etc.
Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published... more Insecta Mundi is a journal primarily devoted to insect systematics, but articles can be published on any non-marine arthropod. Topics considered for publication include systematics, taxonomy, nomenclature, checklists, faunal works, and natural history. Insecta Mundi will not consider works in the applied sciences (i.e. medical entomology, pest control research, etc.), and no longer publishes book reviews or editorials. Insecta Mundi publishes original research or discoveries in an inexpensive and timely manner, distributing them free via open access on the internet on the date of publication. Insecta Mundi is referenced or abstracted by several sources including the Zoological Record, CAB Abstracts, etc. Insecta Mundi is published irregularly throughout the year, with completed manuscripts assigned an individual number. Manuscripts must be peer reviewed prior to submission, after which they are reviewed by the editorial board to ensure quality. One author of each submitted manuscript must be a current member of the Center for Systematic Entomology. Manuscript preparation guidelines are availablr at the CSE website.