Relationships of stream invertebrate communities to deforestation in eastern Madagascar

J BENSTEAD, Michael Douglas, C PRINGLE

    Research output: Contribution to journalArticleResearchpeer-review

    Abstract

    Madagascar has been recently identified as a global hotspot for freshwater biodiversity. Loss of most of its eastern rain forest, combined with a high incidence of micro-endemism and specialization to forest stream habitats, has likely led to extinction of many of the island's stream insect species. We compared habitat and macroinvertebrate community structure in three streams draining protected rain forest within Ranomafana National Park in eastern Madagascar and three agriculture streams draining the park's largely deforested peripheral zone. Multivariate analyses showed that macroinvertebrate communities differed between stream types. Forest streams were characterized by species-rich, diverse communities composed primarily of collector-gatherers and collector-filterers belonging to the orders Trichoptera, Ephemeroptera, Plecoptera, and Diptera. In contrast, relatively depauperate agriculture stream communities were dominated by generalist collector-gatherer taxa mostly belonging to the order Ephemeroptera. Agriculture streams had 0-14% canopy cover, significantly higher mean and maximum water temperatures, and significantly lower benthic organic matter storage than forest streams (71-83% canopy cover). We found no evidence for higher sedimentation rates or nutrient concentrations in agriculture streams. Differences in thermal regime may be important in the declines of certain taxa in agriculture streams (e.g., Plecoptera). However, our data support the hypothesis that differences in stream communities are caused mainly by differences among taxa in ability to track shifts in basal resources (i.e., terrestrial detritus vs. in situ algal production) caused by deforestation. Community simplification and loss of endemic specialist taxa will continue if projections of future deforestation are proved correct. We recommend that stream biodiversity be considered in future conservation planning and propose the creation and maintenance of multiuse riparian forests that could serve both ecological and economic functions. Given that more than 5 �105 km of stream and river channel are affected by tropical deforestation annually, our results have potential applications in other tropical regions.
    Original languageEnglish
    Pages (from-to)1473-1490
    Number of pages18
    JournalEcological Appplications
    Volume13
    Issue number5
    Publication statusPublished - 2003

    Fingerprint

    deforestation
    invertebrate
    agriculture
    macroinvertebrate
    canopy
    biodiversity
    riparian forest
    stream channel
    conservation planning
    thermal regime
    endemism
    habitat
    tropical region
    river channel
    generalist
    sedimentation rate
    detritus
    national park
    community structure
    water temperature

    Cite this

    BENSTEAD, J ; Douglas, Michael ; PRINGLE, C. / Relationships of stream invertebrate communities to deforestation in eastern Madagascar. In: Ecological Appplications. 2003 ; Vol. 13, No. 5. pp. 1473-1490.
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    title = "Relationships of stream invertebrate communities to deforestation in eastern Madagascar",
    abstract = "Madagascar has been recently identified as a global hotspot for freshwater biodiversity. Loss of most of its eastern rain forest, combined with a high incidence of micro-endemism and specialization to forest stream habitats, has likely led to extinction of many of the island's stream insect species. We compared habitat and macroinvertebrate community structure in three streams draining protected rain forest within Ranomafana National Park in eastern Madagascar and three agriculture streams draining the park's largely deforested peripheral zone. Multivariate analyses showed that macroinvertebrate communities differed between stream types. Forest streams were characterized by species-rich, diverse communities composed primarily of collector-gatherers and collector-filterers belonging to the orders Trichoptera, Ephemeroptera, Plecoptera, and Diptera. In contrast, relatively depauperate agriculture stream communities were dominated by generalist collector-gatherer taxa mostly belonging to the order Ephemeroptera. Agriculture streams had 0-14{\%} canopy cover, significantly higher mean and maximum water temperatures, and significantly lower benthic organic matter storage than forest streams (71-83{\%} canopy cover). We found no evidence for higher sedimentation rates or nutrient concentrations in agriculture streams. Differences in thermal regime may be important in the declines of certain taxa in agriculture streams (e.g., Plecoptera). However, our data support the hypothesis that differences in stream communities are caused mainly by differences among taxa in ability to track shifts in basal resources (i.e., terrestrial detritus vs. in situ algal production) caused by deforestation. Community simplification and loss of endemic specialist taxa will continue if projections of future deforestation are proved correct. We recommend that stream biodiversity be considered in future conservation planning and propose the creation and maintenance of multiuse riparian forests that could serve both ecological and economic functions. Given that more than 5 �105 km of stream and river channel are affected by tropical deforestation annually, our results have potential applications in other tropical regions.",
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    BENSTEAD, J, Douglas, M & PRINGLE, C 2003, 'Relationships of stream invertebrate communities to deforestation in eastern Madagascar', Ecological Appplications, vol. 13, no. 5, pp. 1473-1490.

    Relationships of stream invertebrate communities to deforestation in eastern Madagascar. / BENSTEAD, J; Douglas, Michael; PRINGLE, C.

    In: Ecological Appplications, Vol. 13, No. 5, 2003, p. 1473-1490.

    Research output: Contribution to journalArticleResearchpeer-review

    TY - JOUR

    T1 - Relationships of stream invertebrate communities to deforestation in eastern Madagascar

    AU - BENSTEAD, J

    AU - Douglas, Michael

    AU - PRINGLE, C

    PY - 2003

    Y1 - 2003

    N2 - Madagascar has been recently identified as a global hotspot for freshwater biodiversity. Loss of most of its eastern rain forest, combined with a high incidence of micro-endemism and specialization to forest stream habitats, has likely led to extinction of many of the island's stream insect species. We compared habitat and macroinvertebrate community structure in three streams draining protected rain forest within Ranomafana National Park in eastern Madagascar and three agriculture streams draining the park's largely deforested peripheral zone. Multivariate analyses showed that macroinvertebrate communities differed between stream types. Forest streams were characterized by species-rich, diverse communities composed primarily of collector-gatherers and collector-filterers belonging to the orders Trichoptera, Ephemeroptera, Plecoptera, and Diptera. In contrast, relatively depauperate agriculture stream communities were dominated by generalist collector-gatherer taxa mostly belonging to the order Ephemeroptera. Agriculture streams had 0-14% canopy cover, significantly higher mean and maximum water temperatures, and significantly lower benthic organic matter storage than forest streams (71-83% canopy cover). We found no evidence for higher sedimentation rates or nutrient concentrations in agriculture streams. Differences in thermal regime may be important in the declines of certain taxa in agriculture streams (e.g., Plecoptera). However, our data support the hypothesis that differences in stream communities are caused mainly by differences among taxa in ability to track shifts in basal resources (i.e., terrestrial detritus vs. in situ algal production) caused by deforestation. Community simplification and loss of endemic specialist taxa will continue if projections of future deforestation are proved correct. We recommend that stream biodiversity be considered in future conservation planning and propose the creation and maintenance of multiuse riparian forests that could serve both ecological and economic functions. Given that more than 5 �105 km of stream and river channel are affected by tropical deforestation annually, our results have potential applications in other tropical regions.

    AB - Madagascar has been recently identified as a global hotspot for freshwater biodiversity. Loss of most of its eastern rain forest, combined with a high incidence of micro-endemism and specialization to forest stream habitats, has likely led to extinction of many of the island's stream insect species. We compared habitat and macroinvertebrate community structure in three streams draining protected rain forest within Ranomafana National Park in eastern Madagascar and three agriculture streams draining the park's largely deforested peripheral zone. Multivariate analyses showed that macroinvertebrate communities differed between stream types. Forest streams were characterized by species-rich, diverse communities composed primarily of collector-gatherers and collector-filterers belonging to the orders Trichoptera, Ephemeroptera, Plecoptera, and Diptera. In contrast, relatively depauperate agriculture stream communities were dominated by generalist collector-gatherer taxa mostly belonging to the order Ephemeroptera. Agriculture streams had 0-14% canopy cover, significantly higher mean and maximum water temperatures, and significantly lower benthic organic matter storage than forest streams (71-83% canopy cover). We found no evidence for higher sedimentation rates or nutrient concentrations in agriculture streams. Differences in thermal regime may be important in the declines of certain taxa in agriculture streams (e.g., Plecoptera). However, our data support the hypothesis that differences in stream communities are caused mainly by differences among taxa in ability to track shifts in basal resources (i.e., terrestrial detritus vs. in situ algal production) caused by deforestation. Community simplification and loss of endemic specialist taxa will continue if projections of future deforestation are proved correct. We recommend that stream biodiversity be considered in future conservation planning and propose the creation and maintenance of multiuse riparian forests that could serve both ecological and economic functions. Given that more than 5 �105 km of stream and river channel are affected by tropical deforestation annually, our results have potential applications in other tropical regions.

    KW - biodiversity

    KW - community structure

    KW - conservation

    KW - deforestation

    KW - macroinvertebrate

    KW - Indian Ocean

    KW - Indian Ocean islands

    KW - Madagascar

    KW - Ranomafana National Park

    KW - algae

    KW - Diptera

    KW - Ephemeroptera

    KW - Hexapoda

    KW - Insecta

    KW - Invertebrata

    KW - Plecoptera

    KW - Riparia

    KW - Trichoptera

    M3 - Article

    VL - 13

    SP - 1473

    EP - 1490

    JO - Ecological Appplications

    JF - Ecological Appplications

    SN - 1051-0761

    IS - 5

    ER -