Do native intertidal burrowing crabs benefit from non-native Spartina alterniflora?

Transcription

1 Do native intertidal burrowing crabs benefit from non-native alterniflora? College of Environment and Ecology Xiamen University, Fujian, China Hanyu Meng 216/7/18

2 Our team~ Wenwen Liu dvisor Zhengjie Li Dan Peng Yihui Zhang Xiao Chang Xincong Chen Tianbai Chen Yiqing Zheng

3 Introduction Invasive alien species can have serious ecological and economic impacts across the globe (Vilà et al. 211). During the establishment and further spread of invasive species in native ecosystem, the interactions between invasive species and native species will occur (Wan et al. 211). Invasive plants - Native animals alterniflora urrowing crabs

4 Introduction S. alterniflora transforms open mudflats to tall, dense vegetation (Li et al. 29, He et al. 212), suppresses native marsh vegetation and associated animals (Li et al. 29, Ma et al. 211), and at low latitudes, invades mangrove habitat at higher in the intertidal zone (Zhang et al. 212). Zuo Zuo et et al, al, >19 Phragmites From:o Li mangrove From:Yihui Zhang

5 Introduction S. alterniflora transforms open mudflats to tall, dense vegetation (Li et al. 29, He et al. 212), suppresses native marsh vegetation and associated animals (Li et al. 29, Ma et al. 211), and at low latitudes, invades mangrove habitat at higher in the intertidal zone (Zhang et al. 212). Zuo Zuo et et al, al, Phragmites From:o Li mangrove From:Yihui Zhang

6 Phragmites From o Li mangrove From Yihui Zhang In salt marsh, could affect native crab distribution and diets, as well as provide compatible habitats for native crab(wang et al, 28; Qin et al, 211). Mangrove

7 mangrove From:Yihui Zhang In mangrove area, what s the native crabs distribution with the invasion of exotic plant alterniflora? Is there any difference of crab abundance between invasive and native mangrove? Individuals/ day/ trap Individuals/ day/ trap utumn Spring b CD DD D DDDD DDDD D DD D a cccc ccc c cccc c c c c a Habitat Sesarma plicata Metaplax longipes Helice pingi Sesarma bidens Uca arcuata Mangrove Ecotone Mudflat (Li et al. 214, Ecology) C a

8 Parasesarma plicata Metaplax longipes Fig. 1 Location of the field site in mangrove area of Zhangjiang Estuary, Fujian Province, China. ugust, 213 ugust, 214

9 Sampling----pitfall traps (Li et al, 214) Time: 213 and 214 Habitats: Mangrove, S.alterniflora, Unvegtated mudflat Replicate traps: n=15 (16 cm diameter, 25 cm deep, > 15 m apart within habitat) The number of Parasesarma plicata and Metaplax longipes per trap every day for 3 consecutive days in Spring, Summer, utumn and Winter. Pitfall trap Crab investigation

10 Individuals/day/trap Individuals/day/trap Parasesarma plicata Metaplax longipes Mangrove Mudflat Fig. 2 Density of Parasesarma plicata and Metaplax longipes in different habitats. P. plicata was abundant in mangrove and marsh, while M. longipes was abundant in unvegetated mudflat. There was no significant difference of crab density between mangrove forest and marsh.

11 Individuals/day/trap 2.5 Uninvaded mudflat (213) Uninvaded Invaded Parasesarma plicata Invaded by (214) Invasive plant affects the distribution of native crabs. Metaplax longipes Fig. 3 Number of Parasesarma plicata and Metaplax longipes before and after S.alterniflora invading unvegetated mudflat within only one growing season.

12 removal experiment Plots set time: May 215 Treatment: ; removal; Unvegetated mudflat Replicate traps: n=12 Size: 2*2 m removal Parasesarma plicata ind/day/trap Metaplax longipes ind/day/trap removal Mudflat Fig. 4 Density of Parasesarma plicata and Metaplax longipes in each treatment. 215/5 216/5 215/5 216/5

13 Conclusion Parasesarma plicata was abundant in mangrove and marsh, while Metaplax longipes was abundant in unvegetated mudflat. alterniflora could expand the intertidal distribution of native P. plicata but limit M. longipes distribution with S. alterniflora sharply occupying mudflats and displacing mangroves in the upper intertidal of Zhangjiang Estuary. Parasesarma plicata alterniflora + Metaplax longipes

14 Ongoing What are the mechanisms that shaped the patterns of crabs distribution? dditional studies will be conducted to disentangle the roles of the biotic (vegetation, predator, food source) and abiotic (light, temperature, salinity, sediment) factors on the habitat selection of these two crabs(wang, 28; Garside & ishop 214; He & Cui 214).

15 Thank you!

16 Individuals/day/trap Individuals/day/trap C 1.. Spring Summer213utumn Winter Spring Summer utumn 213 Winter Parasesarma plicata Metaplax longipes Parasesarma plicata Mangrove Ecotone Mudflat Spring Summer 214 utumn Winter Metaplax longipes Spring Summer utumn Winter 214 Fig. 2 Number of Parasesarma plicata and Metaplax longipes in the four different habitats in Spring, Summer, utumn and Winter 213 and 214.