Recolonisation potential of zooplankton propagule banks in natural and agriculturally modified sections of a semiarid temporary stream (Doñana, Southwest Spain)

Abstract

The viable propagule banks of a temporary stream were studied from sections with different agricultural history. Hatching of zooplankton (copepods, rotifers and cladocerans) was recorded in the laboratory under controlled temperature and light conditions from an agriculturally modified area with average hydroperiods of about a week per year and two semi-natural reference areas with average hydroperiods of more than 3 weeks per year. We found significant differences in both taxon richness and abundance of zooplankton hatching between areas, which were lower in the agriculturally modified section, compared to the reference sections. Another factor likely to have influenced hatching in our experiment was conductivity, which differed between the two reference sections and might have affected hatching at high conductivities. For restoration purposes, hydrological reconnection of stream segments is important to facilitate dispersal from the high diversity upstream segments to the depleted sites downstream.

Inundation frequency and viability of microcrustacean propagules in soils of temporary aquatic habitats of lower Okavango Delta, Botswana

“…High numbers of microcrustaceans also emerged from the rainpools although species richness of emerged microfauna was poor from these habitats. The study findings agrees with other studies (Boulton and Lloyd, ; Gleason et al ., ; Jenkins and Boulton, ; Frisch et al ., ) by illustrating that microcrustaceans characterized by low species richness and low abundance emerge from temporary aquatic habitats after many years of dryness. Other studies (Boulton and Lloyd, ; Brock, ; Frisch et al ., ) have suggested that only drought resistant microcrustacean species are able to emerge from sediments of temporary aquatic habitats after numerous years of dryness.…”

“…Therefore, absence of ostracods and low abundance of cladocerans in sediments of the rarely flooded floodplains suggest that the propagules of these two groups were the most negatively affected during multiple years of no flooding. These trends confirm observations of other studies (Gleason et al ., ; Jenkins and Boulton, ; Frisch et al ., ) that have reported that the viability of cladoceran eppiphia is greatly affected within the temporary aquatic habitats during many years of no flooding. A decrease in the number of viable cladoceran ephippia in floodplain sediments of the temporary floodplains may have negative impacts on fish production as fish largely prey on cladocerans (Kairesalo and Seppälä, ; Fernando, ; Høberg et al ., ).…”

“…The microcrustacean propagules may remain viable in sediments of temporary aquatic habitats for many years (Hutchinson, ; Hairston et al ., ; Brendonck and De Meester, ) until conducive conditions such as flooding occur (Danks, ; Brendonck et al ., ; Gaikwad et al ., ). The microcrustacean propagules that remain viable in temporary aquatic habitats during the terrestrial phase emerge from the sediments soon after inundation of these habitats (Boulton and Lloyd, ; Brendonck and De Meester, ; Frisch et al ., ). Therefore, microcrustacean propagules that remain viable during the terrestrial phase of these habitats are important to facilitate the (i) recolonization of these habitats when they are rehydrated (De Stasio, ; Hairston, ; Frisch et al ., ; Jenkins and Boulton, ), (ii) movement of microcrustacean diversity from the past through unfavourable environment until conducive conditions reoccur (Brendonck and De Meester, ) and (iii) dispersal because microcrustacean propagules are easily distributed by birds, wildlife, water, wind and fish (Hairston, ; Taylor et al ., ; Louette and De Meester, ).…”

Rotifers of temporary waters

“…Landscape use has an effect on the sediment egg bank of these habitats. For example, Frisch et al found differences in species composition when comparing rotifers hatched from sediment taken from a temporary stream flowing through agricultural lands as compared to two reference zones.…”

Recovery of zooplankton diversity in a restored Mediterranean temporary marsh in Doñana National Park (SW Spain)

“…Just before the restoration project, the egg bank in an old streambed that crosses the estate near the ponds (Fig. 1) was low in diversity and abundance, despite being the only part of the estate that still flooded in winter during the agricultural phase (Frisch et al, 2009). Cattle were eliminated from the estate before the new ponds filled with Fig.…”