Predation And Hoarding On Korean Pine (Pinus Koraiensis) Seeds By Scatter-hoarding Animals In Liangshui Nature Reserve

Synzoochory is a course of plants regeneration lead by hoarding behavior of animals. The research results indicate that frugivorous rodents are the main mammals providing synzoochory.More than 70 rodent species are known to have dispersal behavior benefit for the spread of plant seeds.The plant seeds dispersed by rodents include pignut,pine seeds, acorn etc.The animal species including frugivorous rodents formed stable diffuse coevolution relationship with plant species.The major researched of frugivorous rodent synzoochory developed three directions:describing and analyzing the synzoochory phenomena;exploring the hoarding behavioral mechanism;tracing the seeds fate after hoarding which is the most interested problem of researchers.The diplochory participated by multi-dispersal pattern in tropic and semi-tropic area is another studying highlight.The research efforts in future should be focused on improving the tracking technique of seeds fate,synzoochory research on ecosystem and landscape scale,discussing the effects of synzoochory in the ecosystem function and ecological restoration.The behavior of animals hoarding Korean Pine(Pinus koreansis) seeds was researched in autumn of 2003,2005～2007 in Liangshui Nature Reserves.There are 15 animals predating on Korean Pine seeds in Liangshui Nature Reserves,10 birds species of 6 families,3 orders,5 mammal species of 3 families 2 orders.Among them red squirrels(Sciurus vulgaris),Eurasian nutcracker(Nucifraga caryocatactes),Eurasian Nuthatch (Sitta europaea),chipmunk(Eutamias sibiricus) had behaviors of scatter-hoarding Korean Pine seeds.The ground placement and burying experiment revealed that the animals predated ground seeds intensively,and burying decreased the predation of animals on Korean Pine seeds effectively.Field research works of caching behavior by Eurasian Nuthatch in Liang-Shui Nature Reserve,Xiaoxing'anling Mt.Northeast China in October 16th to 27th.Caching behavior of Eurasian Nuthatch including carrying behavior,determining behavior and hoarding behavior. Average Caching time is(15.3±3.1) s,cache size is 1,cache depth is(1.4±0.5) cm. Caching microhabitat mainly including:live-stand wood,dead-stand wood,log and slope.The hoarding characteristic and cache quantity of Squirrels(Sciurus vulgaris) & Eurasian Nutcrackers(Nucifraga caryocatactes) were investigated in Liangshui Nature Reserve during September 30th to October 8th in 2005.The average cache size of squirrels was 3.02±0.1 and the depth was 2.67±0.08 cm;the average cache size and depth of Eurasian nutcrackers was 3.21±0.22 and 2.73±0.15 cm respectively.No significant difference in cache size and depth was showed between squirrels and Eurasian nutcrackers.The cache density and cache quantity by squirrels are most in primal Korean pine forest.The hoarding quantity of squirrels and Eurasian nutcrackers was 8 686 312±683 360 and 3 190 444±410 377 in the whole Nature Reserve yearly.The total hoarding quantity was 11 876 757±812 304.The hoarding behavior of squirrels and Eurasian nutcrackers is one of the main factors on natural regeneration of Korean pines.The habitat selection and microhabitat utilization for hoarding behavior of squirrels (Sciurus vulgaris) and Eurasian nutcrackers(Nucifraga caryocatactes) are investigated in Liangshui National Nature Reserve.Total 365 big samples and 1463 small samples were investigated in 11 forestry types.Results showed it is different selectivity of squirrels' hoarding behavior and Eurasian nutcrackers' hoarding behavior.The squirrels selected habitat order by major vegetation types is as follows:first natural spruce forest;second original Korean pine forest;third manmade Korean pine forest;fourth mix-conifer-broadleaf forest;fifth manmade spruce forest;sixth birch forest;seventh mix-conifer leaf forest;eighth manmade fallen leaves pine forest;ninth mix-broadleaf forest;tenth natural fir forest;finally other forest.The Eurasian nutcrackers selected habitat order by major vegetation types is as follows:first manmade Korean pine forest;second original Korean pine forest;third natural spruce forest;fourth manmade spruce forest;fifth mix-conifer-broadleaf forest;sixth mix-broadleaf forest;seventh birch forest;eighth mix-conifer leaf forest;ninth manmade fallen leaves pine forest;tenth natural fir forest;finally other forest. The Vanderploeg and Scavia selectivity index,Wi and Ei,were used to evaluate the microhabitat utilization selection of squirrels and Eurasian nutcrackers.Results indicated that their selections are sameness except brush type.Squirrels and Eurasian nutcrackers selected Korean Pine seeds with burgeoning activities. When there were73.2%available seeds in one cone the seeds hoarded by squirrels and Eurasian nutcrackers were esculent 100%.The burgeoning experiment revealed that 60%seeds in caches hoarded by squirrels and Eurasian nutcrackers can bud to seedlings with higher budding rate than that of nature status(41.7%).In winter squirrels recoveryed 85%caches of total caches,and Eurasian nutcrackers recoveryed 79%of total caches.In field the spatial memory ability and pilferer is the main tool of squirrels and Eurasian nutcrackers to recover cache.In little scale,squirrels mainly depend on pilferer to recover cache.In large scale,squirrels mainly depend on spatial memory ability to recover cache.All the factors to be concerned,spatial memory ability play a more important role than pilferer in cache recovery of squirrels in nature.The hoarding distance of Korean Pine(Pinus koreansis) seeds removed by squirrels (Sciurus vulgaris) was analyzed.The cones were marked by label,and observation in field was integrated to artificial placement experiments.The results indicated that Korean pine cones in different places were found and predated by squirrels at different time.The cones in disturbed places(near tourist path) were removed later.All cones disappeared within 10h. New cones(in 2006) and old cones(in 2005) were all predated and hoarded.Squirrels prefer to remove new cones and all the cones were hoarded,but old cones were eaten partly and only part cones were hoarded.Totally 110 marked cones were placed,in which 8 were eaten,102 were removed and hoarded,47 cones(46.1%) were found within 300m radial distance from placing spot.