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1

Effectiveness of Korean pine (Pinus koraiensis) seed dispersal by small rodents in fragmented and primary forests

100%
Yang Y., Yi X.
Polish Journal of Ecology
|
2011
|
tom 59
|
nr 2
The effectiveness of dispersers on seeds of Korean pine (Pinus koraiensis Siebold et Zuccarini) was investigated in three fragmented stands and one primary stand. The proportion of Korean pine trees was less than 7% in the fragmented stands but more than 90% in primary stand. Five estimates related seed dispersal (proportion of removed seeds, scatter-hoarded seeds, cache dynamics, dispersal distance and microhabitat) were assessed to see the effect of forest fragmentation on the probability of seed dispersal of Korean pine seeds. Our results indicated fast seed harvest of Korean pine by small rodents at the seed stations and no difference among the four stands. Scatter-hoarding rodents were potentially important in promoting natural regeneration of Korean pine as revealed by high proportion of seed removal (up to 50%), short seed lifetime from the seed release locations and lower proportion of seeds remained on the ground surface. Although a proportion of seeds were scatter-hoarded in fragmented stands, no seedling successfully established due to heavy predation. Dispersal distances were strongly left-skewed in fragmented stands, indicating that fragmentation is likely to be disadvantageous for longer distance dispersal. The effective dispersal was suffered from a very heavy cost as accompanied by a great portion of seed predation and lower level of scatter-hoarded seeds. Failing to see seedling establishment in fragmented stands rather than in primary stand indicated that fragmentation and deforestation have negative effects on dispersal behavior and consequently seed destination. Artificial tree plantation and pinecone protection are highly recommended for Korean pine regeneration.
2

Scatterhoarding of Manchurian walnut Juglans mandshurica by small mammals: response to seed familiarity and seed size

100%
Yi X., Yang Y.
Acta Theriologica
|
2011
|
tom 56
|
nr 2
Dispersal patterns can be affected by seed familiarity and seed traits, including size, mass, and nutritional value, but these factors have not been intensively studied in the context of seed dispersal processes. Our aim was to study how small rodents respond to seed size and seed familiarity in their pattern of Manchurian walnut (Juglans mandshurica) seeds in two different habitats in temperate forests of northeast China. Our results demonstrated that Apodemus penisulae acts as the most important disperser for Manchurian walnut seeds. Inexperienced small rodents did not reject seeds of the Manchurian walnut and show similar seed removal rates as compared with experienced rodents. Both experienced and naïve rodents actively participated in seed scatterhoarding of Manchurian walnut seeds. Consecutive survey showed that seeds with large size/mass were removed faster than those with small size/mass, indicating a preference for large seeds. However, small seeds scatter-hoarded by small rodents were transported farther than large ones, failing to support the traditional optimization models for various tree species. Small seeds of Manchurian walnut in caches were less likely to be recovered than large ones and showed greater cache survival rates, indicating that small seeds would be more advantageous for regeneration than large seeds in small rodent-dominated forests.
3

Tracking animal-mediated seedling establishment from dispersed acorns with the aid of the attached cotyledons

100%
Yi X., Wang Z.
Acta Theriologica
|
2015
|
tom 60
|
nr 2
Various methods have been used to track seed dispersal of large-seeded species; however, the influence of different seed tracking methods on ecological outcomes of seed dispersal by animals is not well evaluated. Acorn removal by food hoarding animals and the following seedling establishment of Mongolian oak (Quercus mongolica) were investigated in Xiaoxing’anling Mountain, Heilongjiang, northeastern China, by using four different marking methods: plastic tagging, nail insertion, hole drilling, and isotope labeling. The acorn removal speed differed among marking methods, with plastic-tagged acorns being removed more slowly than those marked with nails, holes, and isotope. By checking the attached cotyledons and performing isotope analyses, more seedlings were found to establish from nailed acorns and isotope-soaked acorns than from drilled acorns and plastic-tagged acorns. Plastic-tagged acorns were transported closer than those marked with nails, holes, and isotope. Moreover, seedlings were often found clustered in caches containing acorns marked with plastic tags. Low level of cotyledon predation by animals makes it possible to directly identify focal seedlings of white oaks based on the attached cotyledons. Considering cotyledon predation by animals, coupling minor modification of cotyledons with isotope labeling appears to be an easy way to explore the actual pattern of seed dispersal of large-seeded trees, e.g., oaks.
4

Effects of disperser abundance, seed type, and interspecific seed availability on dispersal distance

81%
Liu C., Liu G., Shen Z., Yi X.
Acta Theriologica
|
2013
|
tom 58
|
nr 3
Seed dispersal distance is influenced by a variety of seed properties and functional responses of dispersers. However, to our knowledge, how and why seed dispersal distances are determined remains poorly understood. In the present study, seeds of sympatric tree species, Pinus koraiensis, Corylus mandshurica, Corylus heterophylla, and Quercus mongolica were released to investigate the effects of rodent abundance, seed type, and seed availability on seed dispersal. Our results showed that seeds of P. koraiensis were dispersed further than those of C. heterophylla and C. mandshurica regardless of the ambient rodent and seed abundances, reflecting a consistent effect of seed type on seed dispersal distances. Seed dispersal distance was greatly facilitated by lower per-capita seed abundance (the ratio of seeds to rodents); however, seed caching and cache survival were benefited from higher per-capita seed abundance. Although seed dispersal and seed caching of a particular tree species can be enhanced by its own seed availability, no consistent influence was detected at interspecific levels, reflecting different interspecific effects of seed availability on seed dispersal of sympatric seed species. Our results provide evidences that the effect of seed availability on seed dispersal should be evaluated in terms of per-capita seed abundance and interspecific effects, rather than the independent influence of seed or disperser abundances.
5

Effects of water deficit on growth of two tree species seedlings in changbai mountains of northeast China

71%
Yi X., Zhang Y., Wang Y., Liu Y., Ji L.
Polish Journal of Environmental Studies
|
2015
|
tom 24
|
nr 2
To understand how temperate coexisting tree species respond to water deficit, the seedlings of two coexisting species, Phellodendron amurense Rupr. And Fraxinus mandshurica Rupr., were transplanted into plastic flowerpots. Three water deficit treatments were used, W1 (60-90% field moisture capacity), W2 (40-60% field moisture capacity), and naturally occurring precipitation (CK), with the aim of investigating the effects of water deficit on the growth of seedlings and competition between them. The result showed that the relative height and diameter of the P. amurense seedlings decreased in the control groups (CP, single P. amurense seedling; CF, single F. mandshurica seedling) but increased in the mixed groups (one P. amurense seedling and one F. mandshurica seedling together) with the water deficit. The water deficit affected the plants by altering the growth of the seedlings and competition between the two species. It was shown that there were greater negative effects on P. amurense due to the manufactured water deficit than on F. mandshurica.
6

Study of the clogging properties of mixed leachate

71%
Xie M., Liu D., Tang Y., Feng M., Yi X.
Polish Journal of Environmental Studies
|
2020
|
tom 29
|
nr 5
7

Carbon isotope composition of plants along altitudinal gradient and its relationship to environmental factors on the Qinghai-Tibet Plateau

71%
Li M., Liu H., Li L., Yi X., Zhu X.
Polish Journal of Ecology
|
2007
|
tom 55
|
nr 1
Distribution pattern of δ¹³C values of plateau plants and their responses to environment along altitudinal gradients were investigated. In the growing season of 2003 (June– August), stable carbon isotope ratios (δ¹³C) of 174 plant samples belonging to 89 species of 20 families and 58 genera along the gradient 2800– 4400 m (above sea level) was studied in six sites on the east edge of Qinghai-Tibet Plateau. The results indicated that the range of δ¹³C values of plants is narrow from –30.2‰ to –25.2‰, which means that none of the species examined belonged to C₄ photosynthetic pathway and all of these species performed C₃ photosynthetic pathway. The average δ¹³C values of plants at 6 sites were positively correlated to altitude (r = 0.974, P <0.01). The results revealed that site-averaged δ¹³C values were negatively correlated with temperature (r = 0.907, P <0.05) as well as CO₂ partial pressure (r = 0.940, P <0.01). The combination of these two factors account for 80% of the variation of δ¹³C values (r² = 0.859, P <0.01). Varying precipitation with increasing altitude does not affect the plant δ¹³C values (r = 0.469, P> 0.05) as well as the sunlight duration(r = 0.630, P> 0.05).
8

Initial start-up characteristics of anaerobic ammonium oxidation in a UASB reactor

61%
Cheng H., Yan Y., Yi X., Wang J., Xu W., Nie H.
Polish Journal of Environmental Studies
|
2020
|
tom 29
|
nr 3
9

Seed predation patterns favor the regeneration of dominant species in forest gaps compared with the understory in an oak-pine mixed forest

61%
Yu F., Shi X., Wang D., Wang T., Yi X., Lou Y.
Acta Theriologica
|
2014
|
tom 59
|
nr 4
Recent studies have demonstrated the higher likelihood of regeneration in forest gaps compared with the understory for the dominant species in pine-oak mixed forest. Here, we tested whether rodent seed predation or dispersal was beneficial for gap regeneration. We tracked the seed predation and dispersal of Quercus aliena var. acuteserrata and Pinus armandii using coded plastic tags in the forest understory close to gaps. Our results demonstrated that the proportions of initial buried seeds of both species were significantly more abundant in the forest understory compared with gaps. After seed caching, however, significantly lower proportions of the seeds of both species survived in the forest understory compared with gaps during the 30-day observation period. The final survival proportions of the seeds cached in the forest understory were lower than those cached in the gaps the next spring, which indicated that small rodents rarely retrieved scatter-hoarded seeds from forest gaps. Our findings suggest that rodent seed predation patterns contribute to the regeneration of the dominant species in gaps compared with the understory in a pine-oak mixed forest. In the study area, reforestation usually involves planting seedlings but direct sowing in forest gaps may be an alternative means of accelerating forest recovery and successional processes.
10

Variations in fungal diversity in a biochar-treated continuous cotton-cropped soil environment through metagenomics-based analyses

51%
Han G., Chen Q., Zhang S., Li G., Yi X., Feng C., Yu C., Lan J.
Polish Journal of Environmental Studies
|
2020
|
tom 29
|
nr 5
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