Effects of food limitation, notonectid prédation, and temperature on the population dynamics of daphnia carinata

Michael J. Barry*

*المؤلف المقابل لهذا العمل

نتاج البحث: المساهمة في مجلةArticleمراجعة النظراء

20 الاقتباسات (SciVal)

ملخص

The relative contributions of invertebrate prédation (Notonectidae: Auisops spp.), food limitation, and certain abiotic factors in driving the population dynamics of Daphnia carinata were studied for a two year period in a large farm dam in southern Victoria, Australia. Detailed measurements were made on the population densities of Daphnia and Anisops spp., the amount of food available, the nutritional status, and the size-specific fecundity of Daphnia. The density of the Daphnia population at the field site oscillated closely with water temperature. The amplitude of the population fluctuations varied seasonally, being much greater during the warmer months of the year and switching to fluctuations with low peaks when water temperature dropped below approximately 15 °C. Anisops spp. densities were greatest in winter and declined during the spring of each year. Nymphs appeared in late spring and early summer and numerically dominated the population. During the warmer periods of the year, the daphnid population went through a series of rapid growth phases leading to over-exploitation of food resources and subsequent population collapses. Daphnia population densities were not correlated with Anisops numbers suggesting that prédation was not a major regulatory factor during the warmer periods of the year. When water temperatures fell below ca. 15 °C daphnid population densities remained low despite high food levels. During this period the impact of Anisops may have been greater. Two distinct phases were identified: a warm water period when food limitation was the main regulatory factor, and a cool water period when Anisops prédation may have been the paramount factor. Low oxygen concentrations were associated with heavy rainfall in the spring and may have had a limiting effect on Daphnia for short periods. Daphnia may have had an important role in sustaining the Anisops population in the pond over each winter.

اللغة الأصليةEnglish
الصفحات (من إلى)545-562
عدد الصفحات18
دوريةInternationale Revue der Gesamten Hydrobiologie
مستوى الصوت82
رقم الإصدار4
المعرِّفات الرقمية للأشياء
حالة النشرPublished - 1997
منشور خارجيًانعم

ASJC Scopus subject areas

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