Biology of Desert Invertebrates

Crawford, Clifford S.

doi:10.1007/978-3-642-85794-2

Cited by 99 publications

(35 citation statements)

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“…Organisms inhabiting desert ecosystems are generally well-adapted to the lack of water and most can survive extended periods without any available water (Crawford 1981, Wharton 2002. Once water becomes available, plants and animals respond immediately to take advantage of the improved conditions (Huxman et al 2004, Schwinning andSala 2004).…”

Section: Introductionmentioning

confidence: 99%

The ecology of pulse events: insights from an extreme climatic event in a polar desert ecosystem

et al. 2012

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Abstract. Climate change is occurring globally, with wide ranging impacts on organisms and ecosystems alike. While most studies focus on increases in mean temperatures and changes in precipitation, there is growing evidence that an increase in extreme events may be particularly important to altering ecosystem structure and function. During extreme events organisms encounter environmental conditions well beyond the range normally experienced. Such conditions may cause rapid changes in community composition and ecosystem states. We present the impact of an extreme pulse event (a flood) on soil communities in an Antarctic polar desert. Taylor Valley, McMurdo Dry Valleys, is dominated by large expanses of dry, saline soils. During the austral summer, melting of glaciers, snow patches and subsurface ice supplies water to ephemeral streams and wetlands. We show how the activation of a nonannual ephemeral stream, Wormherder Creek, and the associated wetland during an exceptional high-flow event alters soil properties and communities. The flow of water increased soil water availability and decreased salinity within the wetted zone compared with the surrounding dry soils. We propose that periodic leaching of salts from flooding reduces soil osmotic stress to levels that are more favorable for soil organisms, improving the habitat suitability, which has a strong positive effect on soil animal abundance and diversity. Moreover, we found that communities differentiated along a soil moisture gradient and that overland water flow created greater connectivity within the landscape, and is expected to promote soil faunal dispersal. Thus, floods can 'precondition' soils to support belowground communities by creating conditions below or above key environmental thresholds. We conclude that pulse events can have significant long-term impacts on soil habitat suitability, and knowledge of pulse events is essential for understanding the present distribution and functioning of communities in soil ecosystems.

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Section: Introductionmentioning

confidence: 99%

The ecology of pulse events: insights from an extreme climatic event in a polar desert ecosystem

et al. 2012

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“…Harvestmen are not well known in deserts (Crawford, 1981;Cokendolpher, 1990;Hunt, 1991), although species have been reported from essentially all deserts (Cokendolpher et al, 1993). We found that Trachyrhinus marmoratus was surprisingly abundant at our study area.…”

Section: Studymentioning

confidence: 48%

“…If parasitism occurs predominantly in the rocky area, the post-parasitic mites would drop off the harvestmen and feed on small insects among the rocks. Oviposition of the mites would likewise take place among or under the rocks where the young would wait for harvestmen hosts.Harvestmen are not well known in deserts (Crawford, 1981; Cokendolpher, 1990;Hunt, 1991), although species have been reported from essentially all deserts (Cokendolpher et al, 1993). We found that Trachyrhinus marmoratus was surprisingly abundant at our study area.…”

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confidence: 49%

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Seasonal Changes in a Population of Desert Harvestmen, Trachyrhinus Marmoratus(Arachnida: Opiliones), From Western Texas

Mackay¹,

Grimsley²,

Cokendolpher³

1992

Psyche: A Journal of Entomology

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INTRODUCTIONOther than a few of the common insects, we know little about arthropod populations in North American Deserts (Crawford, 1981). This seems to be especially true of arachnids. A few papers have appeared on desert spiders, solpugids (Muma, 1980a(Muma, , 1980b and included references), desert scorpions (Polis, 1990) and harvestmen of southwestern New Mexico (Cokendolpher et al., 1993).Harvestmen, like other desert organisms, must synchronize their seasonal activity patterns with yearly changes in environmental conditions. In this paper, we provide information on the phenology of a population of the harvestman Trachyrhinus marmoratus, which is locally abundant on rocky slopes in the northern Chihuahuan Desert. MATERIALS AND METHODS Study AreaOur study area, the Indio Mountain Research Station, is located in the Chihuahuan Desert, 25 km south of Van Horn, Hudspeth Co., TX (30 45' N, 105 0' W). It consists of an area uninhabited and undeveloped by humans, including sloping bajadas and rugged slopes with rocky outcrops. Natural vegetation types range from tobosa-black grama grassland to creosotebush-lechugilla shrubland. Rainfall is normally less than 25 cm/yr, and occurs primarily in late summer and fall. Air temperatures range from below 0 C in the winter to over 40 C in the summer. The specific area we used consists of a volcanic boulder and rock covered ridge at an elevation of 1235 m. The ridge is surrounded on both sides (north and (Cokendolpher, 1981). Although this species is widely distributed, we know little of its biology. Cokendolpher (1981) listed natural history data for other members of the genus, but was unable to present any for this species.We found that populations of both females and males were surprisingly high as early as January (Fig. 1) Psyche [Vol. 99 Estivation has never been examined in opilions, but may account for the absence of activity from September to January, although this seems unlikely as desert rains occur during this period (JulySeptember). Egg laying has previously been reported as occurring either in the spring or late fall (Cokendolpher et al., 1993). Apparently there is either no specific time of the year when egg laying occurs or egg laying occurs in the cooler, moister seasons. The juvenile population was at or near zero until late August when we recorded a large increase, 112 days after we recorded a peak in the adult population (Fig. 1). It is probable that one or more early instars were developing below the surface of the ground before we recorded the peak in the juvenile population.Harvestmen were collected in highest numbers on the rocky ridge. This is especially true of the adults: we only collected two adults (one female, one male) in the surrounding area, 59 specimens collected in the surrounding areas were juveniles. There appear to be two hypotheses to explain these observations: 1) the juveniles were born on the rocky ridge and dispersed into the surrounding areas to avoid competition or 2) the eggs were laid in the open area, and juveniles hatch...

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“…En tercer lugar, de acuerdo con estudios realizados en campos de cultivo, la dieta de las Linyphiidae está constituida en un 48% por especies del orden Collembola (Nyffeler, 1999). Dicha preferencia alimenticia podría resultar ventajosa en las condiciones de alta humedad que caracterizan al suelo de las lomas durante la época húmeda y bajo la influencia de El Niño, las mismas que incrementarían la abundancia de Collembola, dado que dicho factor ha sido determinado como influyente en la actividad, densidad y distribución espacial de este taxón (Crawford, 1981;Alvarez et. al., 1999).…”

Section: Dic-99unclassified

Respuesta De La Comunidad De Arañas Epígeas (Araneae) en Las Lomas De Lachay, Perú, Ante La Ocurrencia Del Evento El Niño 1997-98

2016

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ResumenEl presente estudio describe la respuesta de una comunidad de arañas epígeas ante los cambios ambientales provocados por El Niño (EN) 1997-98 en formaciones de lomas de la Costa Central del Perú. La araneofauna fue muestreada durante los años 1998 y 1999 (cuatro veces por año), usando trampas pitfall distribuidas en un área mixta de loma de herbáceas y loma tipo parque en la Reserva Nacional de Lachay. La respuesta de la comunidad fue evaluada analizando los patrones de variación temporal correspondientes a: la composición y abundancia de familias, las abundancias relativas de los gremios, las variables comunitarias (abundancia, biovolumen por individuo, riqueza y diversidad) y las abundancias de las 10 familias más frecuentes. La familia más abundante fue Linyphiidae, incluyendo el 68% de la abundancia registrada durante los dos años y alcanzando la posición de dominante en seis de las evaluaciones (> 80% de la abundancia por evaluación). Durante la mayor parte del tiempo de estudio, las tejedoras fueron más abundantes que las vagabundas según los valores de la proporción de abundancia tejedoras:vagabundas. El gremio de las tejedoras estuvo representado mayoritariamente por las tejedoras de suelo (= Linyphiidae) durante ambos años. Los gremios particulares de arañas vagabundas, mostraron diferentes tendencias de variación: las cursoriales en vegetación y las emboscadoras fueron más abundantes durante 1998, mientras que las cursoriales en suelo y las perseguidoras lo fueron durante 1999. Las variables comunitarias fueron notoriamente influenciadas por la dominancia de Linyphiidae durante 1998, a consecuencia de ésta la abundancia se incrementó entre Febrero y Agosto, la diversidad disminuyó en el mismo periodo y asimismo, la riqueza y el biovolumen por individuo disminuyeron en Agosto. Entre las diez familias más comunes hubo diferentes tipos de respuesta: cuatro favorables, tres desfavorables, una indeterminada y dos de relativa indiferencia. Palabras clave: Comunidad de arañas epígeas, El Niño 1997-98, patrones de variación temporal, formaciones vegetales de lomas, Reserva Nacional de Lachay, pitfall. AbstractThe present study describes the response of epigeic spider assemblages facing environmental changes caused by the 1997-1998 El Niño event in "lomas" formations of the Peruvian central coast. Spiders were sampled during 1998 and 1999 (four times per year), using pitfall traps that were distributed in a mixed area of herbaceous lomas and park type lomas in the Lachay National Reserve. The response of the assemblage was evaluated analyzing temporary variation patterns corresponding to the following: composition and abundance of families, relative abundance of the guilds, community variables (abundance, individual biovolume, richness and diversity) and abundance of the ten most common families. The most abundant family was Linyphiidae, including 68% of the registered abundance during the two years and reaching a dominant position in six evaluations (> 80% of the abundance per evaluation). During most p...

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Biology of Desert Invertebrates

Cited by 99 publications

References 0 publications

The ecology of pulse events: insights from an extreme climatic event in a polar desert ecosystem

The ecology of pulse events: insights from an extreme climatic event in a polar desert ecosystem

Seasonal Changes in a Population of Desert Harvestmen, Trachyrhinus Marmoratus(Arachnida: Opiliones), From Western Texas

Respuesta De La Comunidad De Arañas Epígeas (Araneae) en Las Lomas De Lachay, Perú, Ante La Ocurrencia Del Evento El Niño 1997-98

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