| Seed dispersal is a base of life stage for plant.Seed dispersal mutualisms are important ecological interactions that can shape plant communities by influencing species distributions,community composition,and the regeneration of populations.myrmecochorous(i.e.ant dispersal seed)is a method of amplify occupy space,diffuse and renew population.Myrmecochorous plants adjust their flowering and fruiting phenologies,seed and elaiosome size,distribution,seed placement to realize ants dispersal seeds effectively.To test myrmecochorous plants would be an adaption for ant dispersal,we use Corydalis DC.(C.caudata?C.incisa?C.racemosa?Corydalis wilfordii Regel)to investigated:(i)the fruiting phenology and plant community of four Corydalis species,and ant species and abundance,analysis their relationship between ants and plant distribution,and discuss relationship of ant abundance and seed relase trait;and(ii)compare different elaiosome function of four myrmecochorous plan though three methods(without-elaiosome?seed desiccation and seed hydration),and(iii)discuss the effect of light intensity and seed placement for C.racemosa.We carry out this study in a deciduous forest at the south slope of the Tongbai Mountains(Hubei Province,China),to evaluate mutualism of myrmecochorous plan and ants.1 All 7716 ants from the four Corydalis DC.plant communities were grounded into 4 subfamilies,13 genera and 18 species,this include 9 species of seed-dispersing ants.The abundance and diversity of ants were depended on Corydalis DC.species,the largest species and diversity is C.incisa(Thunb.)Pers.community.For more than one kind of seed-dispersing ant that per Corydalis DC.plant has,seed-dispersing ant and seed did not shaping a special mutualism relation.Ant distribution has a difference in the Corydalis DC.community by cluster and CCA analysis,and the seed size were most important factoringin our study.2 The results indicated that the initial times of seed release of the studied species occurred mostly in late April and/or early May.Three plant species differed significantly in the duration times of seed release.In addition,the probability of maximum seed release also differed significantly among three plant species,peaking either in early May or in late May.The effective ant disperser of C.caudate plants was Pheidole nietneri,and the abundance of ant increased with increasing seed availability,peaking in the end of the fruiting period.The effective ant dispersers of C.incise plants were Pristomyrmex pungens,Crematogaster osakensi,and Liometopum sp.The abundance of all these ants increased with increasing seed availability,peaking in early May for Pristomyrmex pungens and in mid May for both Crematogaster osakensi and Liometopum species.The effective ant disperser of C.racemosa plants was Paratrechina flavipes,and the abundance of ant increased with increasing seed availability,peaking in mid May and in late June respectively.The species composition of the seed-dispersing ant guild did not change throughout the seed-release period.Importantly,both non-effective ant dispersers and ants that do not transport seeds were not active during the seed-release period.In contrast,they are active after fruiting finished,especially the ants that do not transport seeds.3 We contrast seed and elaiosome size found that the largest and smallest seed is C.incise,and C.racemosa,respectively,but claiosomc of C.caudate and C.wilfordii are bigger.The attraction of elaiosome for ant is break down when without-elaiosome and seed desiccation.It was found seed remove rate decrease then increase with the duration of hydration for C.incise,C.caudate and C.wilfordii,but that has a weak effect for C.racemosa.4 The removal peaking of C.racemosa is early 1 hour at the sunndy than other weather.Ant removal seed numbers are change with time variation under 0 layer level,and ant removal number is nearly to 0 when light is very severe.While 1 layer and 2 layer levels,the change of ant removal seed number is nearly immobile.Moreover,ant removal numbers are more than 2 multiple under shady condition contrast to sundy.5 Ant removal seed numbers and removal rate are increasing under seed aggregation placement,and ant removal seed numbers and rate is largest at 50 seeds placement case.In addition,ant removal number has a striking different between 50 seeds and other four seeds placement,while others have no difference.The effective ant of Tetramorium caespium has a chosen on different seed placement pattern,such as touch and hesitation.The result is suggested that dispersal ants have a difference in the four Corydalis DC communty,which is dominated by seed size.While main dispersal ant numbers is increasing with seeds releases numbers,and dispersal ants have a vigorous activity when seeds release is maximum,their seed release peaks were even more finely tuned to the activity pattern of particular ant species as well.Elaiosome have attracted for ant dispersal seed,its function depend on myrmecochorous species.Light would reduce ant's activity,and have a high removal rate at the shady place.The aggregation of C.racemosa seed,the high removal rate ants have.This revealed that abiotic and biotic would influence ant activity during ant dispersal process. |
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