How do Water Regime and Grazing Alter the Reproductive Capacity of Aquatic Plants?

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Dr Margaret A. Brock
Botany, Rural Science and Natural Resources, University of New England
Environment Australia, 2000

Figures

Figure 1: Water regimes in University of New England Experimental wetlands from 1997-2000. a) Spring Fill, Autumn Fill and Twice Fill (autumn and spring) regimes n=4 b) Mimic and permanent regimes n=2.

Figure 2: Water regimes of natural New England wetlands 1992-2000: Llangothlin, Mother of Ducks, Racecourse and Barleyfields lagoons.

Figure 3: Sequential development of vegetation under Autumn Fill water regime in the UNE Experimental Wetlands. (a) Water regime changes from 1997-2000. (b) Year to year changes: summer vegetation (January) 1998,1999 and 2000. (c) Seasonal changes in 1999: Summer (January), Autumn (March), Winter (July) and Spring (November). (Figure is unavailable in electronic form)

Figure 4: Sequential development of vegetation under Spring Fill water regime in the UNE Experimental Wetlands. (a) Water regime changes from 1997-2000 (b) Year to year changes: summer vegetation (January) 1998,1999 and 2000 (c) Seasonal changes in 1999: Summer (January), Autumn (March), Winter (July) and Spring (November). (Figure is unavailable in electronic form)

Figure 5: Sequential development of vegetation under Twice Annual Fill water regime in the UNE Experimental Wetlands. (a) Water regime changes from 1997-2000 (b) Year to year changes: summer vegetation (January) 1998,1999 and 2000 (c) Seasonal changes in 1999: Summer (January), Autumn (March), Winter (July) and Spring (November). (Figure is unavailable in electronic form)

Figure 6: Sequential development of vegetation under Mimic water regime in the UNE Experimental Wetlands. (a) Water regime changes from 1997-2000 (b) Year to year changes: summer vegetation (January) 1998,1999 and 2000 (c) Seasonal changes in 1999: Summer (January), Autumn (March), Winter (July) and Spring (November). (Figure is unavailable in electronic form)

Figure 7: Sequential development of vegetation under Permanent water regime in the UNE Experimental Wetlands. (a) Water regime changes from 1997-2000 (b) Year to year changes: summer vegetation (January) 1998,1999 and 2000 (c) Seasonal changes in 1999: Summer (January), Autumn (March), Winter (July) and Spring (November). (Figure is unavailable in electronic form)

Figure 8: Functional groups of aquatic plants used for interpretation of results (after Brock and Casanova 1997). (Figure is unavailable in electronic form)

Figure 9: Total and average (+/- SE) species richness (SR) for water regimes in the UNE Experimental Wetlands between December 1997 and April 2000.

Figure 10: Total species richness of functional groups (FG SR) for each water regime in the UNE Experimental wetlands between December 1997 and April 2000. Water regimes: AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill. Functional groups: TDR= Terrestrial-dry, TDA= Terrestrial-damp, AT= Amphibious fluctuation-tolerator, AR= Amphibious fluctuation-responder, S= Submerged

Figure 11: Number of water regimes in which species occur. Number of species in different functional groups (a) present and (b) reproducing in 1 to 5 water regimes. For (b) zero (0) water regimes indicates species present but not reproducing in any regime. Functional groups: TDR= Terrestrial-dry, TDA= Terrestrial-damp, AT= Amphibious fluctuation-tolerator, AR= Amphibious fluctuation-responder, S=Submerged.

Figure 12: Dendrogram showing separation of plant communities over time in summer 97,98 and 99 for 5 different water regimes in the UNE Experimental wetlands. (AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill) at 5m from the deepest point in each wetland.

Figure 13: Dendrogram showing separation of plant communities over time in autumn 97,98 and 99 for 5 different water regimes in the UNE Experimental wetlands. (AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill) at 5m from the deepest point in each wetland.

Figure 14: Number of species (a) present and (b) reproducing, for the two seed bank strips: spring-planted (spr) and autumn-planted (aut)) in January and May 1998 under different water regimes in the UNE Experimental Wetlands. Water regimes: AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill.

Figure 15: Number of plant species (a) present and (b) reproducing under different water regimes over time in the UNE Experimental Wetlands. Water regimes: AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill.

Figure 16: Water regimes imposed in the "water regime and grazing tank trial". (Figure is unavailable in electronic form)

Figure 17: Average number of species (+/- SE) reproducing (a) sexually and (b) vegetatively under different water regimes and clipping treatments in the "water regime and clipping tank trial' March 1999. Water regimes are shown in Figure 16.

Figure 18: Total species richness of functional groups at Llangothlin Lagoon (LL), and the Mimic (M) and Permanent (P) water regimes at the UNE Experimental Wetlands , in autumn (Aut98) and spring (Spr98) in 1998. Functional groups: TDR= Terrestrial-dry, TDA= Terrestrial-damp, AT= Amphibious fluctuation-tolerator, AR= Amphibious fluctuation-responder, S= Submerged.

Figure 19: Average species richness (+/- SE) germinating from the newly developed seed bank from sediment from different water regimes in two seasons (Autumn and Spring 1999) in UNE Experimental Wetlands. Sediment source: AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill, SA= Sand, SB= original donor seed bank.

Figure 20: Average number of seedlings germinating from newly developed seed banks from sediment from different water regimes in the UNE Experimental wetlands. Sediment source: AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill, SA= Sand, SB= original donor seed bank. Functional groups: TDR= Terrestrial-dry, TDA= Terrestrial-damp, AT= Amphibious fluctuation-tolerator, AR= Amphibious fluctuation-responder, S= Submerged.

Figure 21: Seed bank development: total number of species in each sediment source split by functional group and season. Sediment source: AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill, SA= Sand, SB= original donor seed bank. Functional groups: TDR= Terrestrial-dry, TDA= Terrestrial-damp, AT= Amphibious fluctuation-tolerator, AR= Amphibious fluctuation-responder, S= Submerged.

Figure 22: Dendrogram showing separation of newly developed seed banks from sediment from different water regimes and in different seasons, based on species presence and number. Codes are as follows; Sediment source: AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill, SA= Sand, SB= original donor seed bank. Numbers 1-4 indicates replicate number. Au= sediment collected in Autumn 1999, Sp= sediment collected in Spring 1999.

Figure 23: Dominant species in the extant vegetation (V) and the seed bank (SB) under different water regimes in the UNE Experimental Wetlands in autumn and spring 1999. Water regimes: AF= Autumn Fill, M= Mimic, P= Permanent, SF= Spring Fill, TF= Twice Annual Fill. Functional groups: TDR= Terrestrial-dry, TDA= Terrestrial-damp, AT= Amphibious fluctuation-tolerator, AR= Amphibious fluctuation-responder, S= Submerged.