Hydraulic properties and drought response of a tropical bamboo (Cephalostachyum pergracile)

Bamboo plants are an essential component of tropical ecosystems,yet their vulnerability to climate extremes,such as drought,is poorly understood due to limited knowledge of their hydraulic properties.Cephalostachyum pergracile,a commonly used tropical bamboo species,exhibited a substantially higher mortality rate than other co-occurring bamboos during a severe drought event in 2019,but the underlying mechanisms remain unclear.This study investigated the leaf and stem hydraulic traits related to drought responses,including leaf-stem embolism resistance(P50leaf;P50stem) estimated using optical and X-ray microtomography methods,leaf pressure-volume and water-releasing curves.Additionally,we investigated the seasonal water potentials,native embolism level(PLC) and xylem water source using stable isotope.We found that C.pergracile exhibited strong resistance to embolism,showing low P50leaf,P50stem,and turgor loss point,despite its rapid leaf water loss.Interestingly,its leaves displayed greater resistance to embolism than its stem,suggesting a lack of effective hydraulic vulnerability segmentation(HVS) to protect the stem from excessive xylem tension.During the dry season,approximately 49% of the water was absorbed from the upper 20-cm-deep soil layer.Consequently,significant diurnal variation in leaf water potentials and an increase in midday PLC from 5.87±2.33% in the wet season to 12.87±4.09%in the dry season were observed.In summary,this study demonstrated that the rapid leaf water loss,high reliance on surface water,and a lack of effective HVS in C.pergracile accelerated water depletion and increased xylem embolism even in the typical dry season,which may explain its high mortality rate during extreme drought events in 2019.

Forest characteristics,population structure and growth trends of threatened relict Pseudotsuga forrestii in China

Pseudotsuga forrestii is a relict evergreen coniferous tree species in Pinaceae endemic to China.P.forrestii tree numbers have greatly decreased due to deforestation,over-utilization and habitat degradation.Here we clarify P.forrestii community types,structure,species diversity,seedling recruitments and growth trends.We identified four P.forrestii community types:(1)Pseudotsuga forrestii-Quercus guyavifolia-Acer davidii evergreen coniferous and broad-leaved mixed forest;(2)Pseudotsuga forrestii-Pinus yunnanensis-Quercus guyavifolia evergreen coniferous and broad-leaved mixed forest;(3)Pseudotsuga forrestii evergreen coniferous forest;(4)Pseudotsuga forrestii-Abies georgei var.smithii evergreen coniferous forest.P.forrestii forests are characterized by both warm temperate and temperate affinities.Simpson diversity,Pielou evenness,Shannon-Wiener diversity indices ranged from 0.75 to 0.76,0.74-0.81,and 1.62-1.93,respectively,with no significant differences among the four forest types.The forest stratification was multilayered.The canopy layer was generally 10-25 m tall,with the emergent layer reached 25-42 m.DBH and age structures of P.forrestii showed multimodal distributions.Its maximum age P.forrestii was 570 years with a DBH of 143 cm.The growth of annual ring width of P.forrestii was slow,and generally decreased with age,whereas the basal area at the breast height increased with age.Established seedlings/saplings were mainly found in unstable micro-habitats.Regeneration of P.forrestii depends on moderate natural disturbances.Finally,we provide recommendations for P.forrestii conservation.

An unprotected vulnerable relict subtropical conifer-Keteleeria evelyniana: Its forests, populations, growth and endangerment by invasive alien plant species in China

Relict subtropical coniferous forests in China face severe fragmentation,resulting in declining populations,and some are under significant threat from invasive alien species.Despite the crucial importance of understanding forest dynamics,knowledge gaps persist,particularly regarding the impact of invasive plants on vulnerable natives like Keteleeria evelyniana.In this study,we investigated the impact of invasive plants on the regeneration of forests dominated by K.evelyniana,a subtropical relict species in southwestern China.For this purpose,we characterized forest dynamics of 160 forest plots featuring K.evelyniana as the primary dominant species and determined whether the presence of invasive plants was correlated with regeneration of K.evelyniana.We identified four distinct forest types in which K.evelyniana was dominant.We found that radial growth of K.evelyniana trees is faster in younger ageclasses today than it was for older trees at the same age.The population structure of K.evelyniana in each forest type exhibited a multimodal age-class distribution.However,three forest types lacked established saplings younger than 10 years old,a situation attributed to the dense coverage of the invasive alien Ageratina adenophora.This invasive species resulted in a reduction of understory species diversity.Additionally,our analysis uncovered a significant negative correlation in phylogenetic relatedness(net relatedness index)between native and invasive alien plant species in eastern Yunnan.This suggests closely related invasive species face heightened competition,hindering successful invasion.Taken together,our findings indicate that successful establishment and habitat restoration of K.evelyniana seedling/saplings require effective measures to control invasive plants.

Perception and Attitudes of Local Communities Towards Wild Elephant-related Problems and Conservation in Xishuangbanna,Southwestern China

The problem of wild elephants, or human-elephant conflict (HEC), influences the daily life of local communities and hinders the conservation of wild elephants.The perception and attitudes of local communities who inhabited the frontiers between human activities and wild elephant movement are important to the mitigation of the HEC and conservation of wild elephants. To analyze the perception and attitudes of local communities, the Participatory Rural Appraisal (PRA) was used in the investigation of 423 interviewees from 22 villages in Xishuangbanna from July 2009 to February 2010. The results indicated that local communities had their views on the elephant-related problems. In field survey, we found that 66.5% of interviewees were willing to support, participate in, and assist in the conservation of wild elephants;33.5% of interviewees were opposed or indifferent to such conservation, because their livelihoods and even their lives were endangered by wild elephants. These views and attitudes were influenced by local communities′perception of HEC, education level, gender and self-interest. Therefore, it is necessary to analyze the diverse views among local communities and balance profits and costs in addressing HEC.

Species richness, forest types and regeneration of Schima in the subtropical forest ecosystem of Yunnan, southwestern China

Background: Schima genus of Theaceae is confined to subtropics and tropics of South, East and Southeast Asia.Thirteen species of Schima are distributed in subtropical China. Many of them appear as dominant canopy species in the subtropical forests. To date, Schima species richness distribution patterns of China have remained unknown.Meanwhile, there has been a longtime debate as to whether forests dominated by Schima species are early or late successional forests. We aim to clarify Schima species richness patterns and these species' roles in the forest succession and regeneration dynamics of the subtropical ecosystem in Yunnan Province, China.Method: We mapped Schima species richness distribution patterns in China. Based on 71 vegetation plots, we analyzed forest characteristics, population structure, and regeneration dynamics of Schima species in Yunnan.Results: Yunnan was found to harbor the greatest richness and the highest rarity-weighted richness of Schima species in the subtropical regions of China. We classified five primary and six secondary forest types containing Schima species as one of dominants. Yunnan had the high floristic diversity and varying stand structure of forests containing Schima species. The Schima species studied generally had a sporadic regeneration type and a long lifespan. Four species(Schima argentea, Schima villosa, Schima sinensis, Schima sericans) were shade-intolerant. But three species(Schima noronhae, Schima khasiana and Schima wallichii) were considered as bi-modal type species having shade-intolerant and shade-tolerant traits. Schima noronhae was seen to be a top dominant in late successional forests, while S. wallichii was found as a top-dominant in early or middle or late successional forests. S.khasiana, Schima villosa, Schima sinensis usually appeared as a top dominant in early or middle successional secondary forests, though they also presented as a second dominant in late-successional forests. Schima argentea and Schima sericans dominated only in the early or middle/seral successional forests. Schima species' regeneration establishment depended mainly on forest canopy gap formation through moderate human and natural disturbances.Conclusions: Yunnan has high species richness and rarity-weighted richness of Schima. Both moderate human and natural disturbances have provided regeneration niches for Schima species. Some of the Schima species studied as a second dominant(rare as the top-dominant) present in the late-successional forests. Some of them are more often as the top-dominant in early or middle successional forests, where as time goes by the dominance of Schima species would be replaced by their associated dominant taxa such as Castanopsis species.

Forest characteristics and population structure of Glyptostrobus pensilis, a globally endangered relict species of southeastern China

The Chinese water pine Glyptostrobus pensilis is the sole surviving species of the genus Glyptostrobus. It is endemic to southern China, central Vietnam, and eastern Laos, and today it is nearly extinct in the wild. Forest community characteristics and population structure of G. pensilis in China have remained un-known up to now. We investigated six swamp forest stands and analyzed their forest community characteristics (i.e. vertical stratification, species composition, and diversity) and population structure, including the frequency distribution of DBH (diameter at breast height) and age-classes as found in Fujian Province, southeastern China. The vertical stratifications of all the forest stands were rather simple. The remaining wild specimens ranged from roughly 15 to some 357 years for an average of ca. 85 years, with only a few individuals less than 20 years old. Compared with the stands and populations of G. pensilis in Vietnam, the taxonomic compositions of the stands in the two regions were different, except for the dominant species-G. pensilis. The Shannon-Wiener index showed the overstory of each stand had much lower diversity (0.26 on average) in Fujian Province than that (1.97 on average) in Vietnam, whereas the diversity indices were about the same (around 2.41) for the understories in the two regions. Furthermore, we discovered 18 G. pensilis seedlings at the study sites in Fujian Province. This discovery demonstrates that G. pensilis regeneration is extremely poor and its populations are declining, although these populations are rela-tively healthier than those in Vietnam.

Bird diversity and waterbird habitat preferences in relation to wetland restoration at Dianchi Lake, south-west China

Background:Restoration projects have been implemented worldwide to mitigate the adverse effects of the loss and degradation of wetland habitats.Much research has been carried out on the impacts on birds of wetland restoration and management projects in China. Studies have mainly investigated central or coastal wetlands,while inland wetlands in remote areas have been much less studied. We focused on examining the response of wild birds to wetland restoration in Dianchi Lake,south-west China. Methods: The line transect method was performed at 26 sampling plots.Three of these were in the city,and to acquire all wild bird data 23 plots were located every 2-8 km along the shore of Dianchi Lake, between December 2011 and November 2013.We collected all related bird records by searching the available literature, articles, newspapers and records of birdwatchers to compare species variation before and after implementation of wetland restoration.To measure the relationships between waterbird assemblages and habitat structures, we used canonical correspondence analysis (CCA) to pair the main matrix of bird assemblages with a second matrix of habitat variables. Results: We recorded 182 bird species belonging to 51 families and 17 orders. Of the species, 42 were new records for Kunming City and 20 were new records for Yunnan Province. Ten waterbird species were found to have disappeared from the shore of Dianchi Lake.CCA results indicated that waterbirds could be divided into four categories based on their habitat preference:synanthropic (wintering gulls), special habitat (shorebirds),semi-natural (wintering coots and ducks) and disturbance-tolerant (resident) species.Conclusions:Our study is the first to consider the entire wild bird community throughout the year and discuss the species variation before and after wetland restoration projects launched for Dianchi Lake.Distinct habitat requirements of different waterbird groups were detected in our study,suggesting different types of restoration and management should be implemented.

Measuring Tourist’s Water Footprint in a Mountain Destination of Northwest Yunnan, China

Monitoring and minimizing tourist’s water consumption is essential for the sustainable development of mountain destinations in the world. However, available data and a generally accepted protocol on such measurement are still limited. This study uses water footprint accounting to quantify tourist’s water demand in the Liming valley, a World Heritage site and a rapidly growing tourism destination in Northwest Yunnan, China. Both the water for direct and indirect use is taken into account based on the consumptive behavior of the tourists in the valley. Data were collected through guesthouse monitoring and a tourist survey in the 2005 tourist season. The results indicate that an average tourist leaves behind a footprint of 5.2 m3 on local water resources per day. Food production and waste dilution are the two most important water consumption factors. The results also show tourists consume more water than the local residents on per capita basis. This suggests more commitment is necessary to cope with this stress by individual tourists. Management implications to make water use more sustainable in mountain destinations are derived from this study.

Effects of climate change on potential habitats of the cold temperate coniferous forest in Yunnan province, southwestern China

We built a classification tree （CT） model to estimate climatic factors controlling the cold temperate coniferous forest （CTCF） distributions in Yunnan province and to predict its potential habitats under the current and future climates, using seven climate change scenarios, projected over the years of 2070-2099. The accurate CT model on CTCFs showed that minimum temperature of coldest month （TMW） was the overwhelmingly potent factor among the six climate variables. The areas of TMW〈-4.05 were suitable habitats of CTCF, and the areas of -1.35 〈 TMW were non-habitats, where temperate conifer and broad-leaved mixed forests （TCBLFs） were distribute in lower elevation, bordering on the CTCF. Dominant species of Abies, Picea, and Larix in the CTCFs, are more tolerant to winter coldness than Tsuga and broad-leaved trees including deciduous broad-leaved Acer and Betula, evergreen broad- leaved Cyclobalanopsis and Lithocarpus in TCBLFs. Winter coldness may actually limit the cool-side distributions of TCBLFs in the areas between -1.35℃ and -4.05℃, and the warm-side distributions of CTCFs may be controlled by competition to the species of TCBLFs. Under future climate scenarios, the vulnerable area, where current potential （suitable ＋ marginal） habitats （80,749 km^2） shift to non-habitats, was predicted to decrease to 55.91% （45,053 km^2） of the current area. Inferring from the current vegetation distribution pattern, TCBLFs will replace declining CTCFs. Vulnerable areas predicted by models are important in determining priority of ecosystem conservation.

Nature Conservation versus Scenic Quality:A GIS Approach towards Optimized Tourist Tracks in a Protected Area of Northwest Yunnan,China

Development of appropriate tourism infrastructure is important for protected areas that allow public access for tourism use.This is meant to avoid or minimize unfavourable impacts on natural resources through guiding tourists for proper use.In this paper,a GIS-based method,the least-cost path(LCP) modelling,is explored for planning tourist tracks in a World Heritage site in Northwest Yunnan(China),where tourism is increasing rapidly while appropriate infrastructure is almost absent.The modelling process contains three steps:1) selection of evaluation criteria(physical,biological and landscape scenic) that are relevant to track decision; 2) translation of evluation criteria into spatially explicit cost surfaces with GIS,and 3) use of Dijkstra's algorithm to determine the least-cost tracks.Four tracks that link main entrances and scenic spots of the study area are proposed after optimizing all evaluation criteria.These tracks feature lowenvironmental impacts and high landscape qualities,which represent a reasonable solution to balance tourist use and nature conservation in the study area.In addtion,the study proves that the LCP modelling can not only offer a structured framwork for track planning but also allow for different stakeholders to participate in the planning process.It therefore enhances the effectivenss of tourism planning and managemnt in protected areas.

Effects of High Temperature Treatment on Seed Germination of Dodonaea viscosa(L.) Jacq

Seeds of Dodonaea viscosa （L.） Jacq, a representative species in dry and hot valleys in Southwest China, were chosen as experimental materials. In this experiment, the D. viscosa seeds were treated at 40, 60, 80 and 100℃ respectively before germination to study impacts of high temperature treatment on their generation rate and to further discuss the roles of fire during the process of vegetation formation in dry and hot valley areas of China. The results show that when the temperature was higher than 40 ℃, the germination rate of D. viscosa seeds was significantly higher than that of the control group, and the heat shock effect was apparent. The germination rate was the highest when the seeds were treated at 80 ℃ for 10 min, reaching 63.00%±2.55%. There was still a significant heat shock effect on the D. viscosa seeds which were stored for one year. In comparison with the conventional method of soaking seeds in hot water, the germination rate of D. viscose seeds which were treated at high temperature before germination increased significantly.

Study on Control Scheme for Nonpoint Source Pollution in Dahe Reservoir Water Source Protection Area of Dianchi Lake Basin

[ Objective] The research aimed to study control scheme for nonpoint source pollution in Dahe Reservoir water source protection area of Dianchi Lake basin.[ Method] On the basis of the SPOT5 satellite remote sensing imagery in 2010 and field investigation of GPS record, ecological design for nonpoint source pollution control in Dahe Reservoir water source protection area of Dianchi Lake basin was conducted. Then, the effects of optimization measures were evaluated by the reductions of N and P outputs on different land-use types. E Resultl Control functions of the water source protection area on soil erosion and the emissions of N, P and other pollutants would be promoted after optimization. The optimization meas- ures had a significant effect for prevention and control of the non-point source pollution in the water source protection area. [ Conclusion] The re- search provided scientific basis for promoting ecological construction of the small green basin in Dahe Reservoir water source protection area of Di- anchi Lake basin.

Seasonal Dynamics of the Soil Moisture in Yuanmou Dry-Hot Valley of Yunnan

[ Objective] The research aimed to study seasonal dynamics of the soil moisture in Yuanmou Dry-Hot Valley of Yunnan. [ Method] We investigated soil moisture in rainy season in Yuanmou Dry-Hot Valley. By combining completed research about soil moisture in dry season, data in rainy and dry seasons were contrasted to study seasonal dynamics of the soil moisture in the zone. [ Resultl Soil moisture in rainy season increased with the depth of soil, but would decrease within 1.0 m below the root layer. The soil moisture of grassland was higher than that of the woodland, while soil moisture of the savanna was higher than that of the woodland but lower than that of the grassland. In addition, compared with soil mois- ture in dry season, it is clear that to avoid forming permanent soil desiccation, based on soil and hydrology conditions in Yuanmou, it is better to plant grass not tree in Yuanmou when we do something about ecological restoration. [ Condusion] The research had certain guidance significance for planting agricultural and economic crops and carrying out ecological restoration in Yuanmou Dry-Hot Valley.

Woolly and overlapping leaves dampen temperature fluctuations in reproductive organ of an alpine Himalayan forb

Aims studying the ecological significance of highly specialized morpho-logical traits evolved by alpine plants could help us to understand the adaptation and evolution of these plants under severe alpine environ-ment.We explored the adaptive significance of woolly and overlap-ping leaves for reproduction in Eriophyton wallichii,a perennial herb native to the subnival belt of the Himalaya-Hengduan mountains.Methods We examined whether the trichomes could influence the leaf wet-tability,temperature and leaf reflectance spectra in the lab.and we investigated the thermal benefits of the woolly and overlapping leaves for flowers and fruits in the field.Pollen viability and seed germination were also examined in the lab to assess whether these leaves enhance reproductive fitness.Important Findingsour results showed that dense trichomes impart good water repel-lency,absorption of solar radiation and accumulation of leaf heat.The woolly and overlapping leaves increased the interior tempera-ture of flowers and fruits to an optimal level on sunny hours,but prevented them from overheating when transient intense solar radi-ation occurs.This kept optimal temperatures in plants’reproduc-tive organs,thus promoting the development of pollen and seed in alpine environment.

Rapid assessment and explanation of tree species abundance along the elevation gradient in Gaoligong Mountains,Yunnan,China

这篇文章在西方云南在 Gaoligong 山沿着举起坡度与气候的变量介绍树种类丰富和它的协会的分析，中国。从在 Gaoligong 山区的科学报纸和书的数据被收集并且外推阐明由检验气候的变量的沿着坡度的在举起范围和树种类的举起中点之间的举起模式和关系的机械学的理解。树种类丰富与一座山峰显示出一个单峰的模式在中间举起(大约 2000 m ) 并且有一个狭窄的举起范围的种类发生在更高或更低的举起，当一个更宽的举起范围在坡度的中间被发现时。树种类丰富是最高在温度和水可获得性是中等的的地方。在影响种类的气候的变量之间的关系看起来由于在不同坡度改变的这些效果的直接、间接的因素，和效果。

Forest characteristics and population structure of a threatened palm tree Caryota obtusa in the karst forest ecosystem of Yunnan,China

Caryota obtusa of Arecaceae is a fascinating palm tree native to southwestern China,India,Myanmar,Thailand,Laos and Vietnam.It is an economically important and threatened species and appears as a canopy dominant in some karst areas in Yunnan.We aim to clarify the forest structure,species diversity,population status and regeneration dynamics of C.obtusa in the karst forest ecosystem of Yunnan,China.We established 56 vegetation plots dominated by C.obtusa in 10 counties of southern Yunnan.Based on the plot data,we analyzed the community stratification,floristic composition and C.obtusa’s population structure.We used questionnaires to interview local people and recorded the human activity history in C.obtusa-dominated forests.Caryota obtusa palm forests were distributed on limestone mountain slopes and gullies.There were seven forest community types.The stratification of each community included arborous layer,shrub layer and understory.The communities had rich species composition.For all the plots as a whole of each community type,Shannon–Wiener diversity index of either woody or herbaceous species ranged from 2.1 to 3.8.The diameter at breast height(DBH)-class frequency distribution of C.obtusa was a multimodal type.The regeneration was sporadic and dependent on intermediate natural disturbances.In the current population structure,a number of C.obtusa trees with small DBHs consisted mainly of the forest communities with no or a slight degree of human disturbances.Intensive human activities terribly hindered recruitment of C.obtuse,followed by the medium intensity of human activities.

Factors acting on the distribution region of Carlemanniaceae:Rainfall,temperatureand the plants' biological characteristics

在东亚和热带亚洲的家庭 Carlemanniaceae，包括二个类， Carlemannia 和 Silvianthus，主要沿着 Himalaya 山的南部的脚和云南高原的西方、南部的接口被散布。为 Carlemannia 四角形的主要繁殖过程一被授粉实验在这个工作作为自花受粉验证。为两 C 的种子的萌芽率。当种子在二个月以后是镇定的时， and Silvianthus bracteatus 能百分之百到达的四角形，当率减少了到 25% 时当收集发生在上一年时。种子没有休眠阶段，这被发现，并且他们的种子银行具有短暂土壤类型。在地观察，为水果的裂开地位证明他们的种子不能被囊为疏开有效地逐出。在从年分析温度和降雨数据以后 1971～2000 ，它被看那年度降雨，最低吝啬的月刊一年里的温度，和在一个月内的极端最低温度在 Carlemanniaceae 的分发范围上有大效果，当吝啬的年度温度有更小的效果时。Carlemanniaceae 的狭窄的分发范围被多重因素影响，例如短花粉疏开距离和短暂土壤种子银行。Carlemanniaceae 的人口尺寸被降雨的水平，不是由任何单个变量容易也影响。

Vegetation distribution pattern in the dam areas along middle-low reach of Lancang-Mekong River in Yunnan Province, China

Lancang-Mekong River Basin is one of ecoregions with rich biodiversity and high ecological values in the world. The basin has been strongly affected by human activities, particularly by dam construction. This study was conducted to investigate the vegetation distribution patterns in the dam areas along middle-low reach of the Lancang-Mekong River in Yunnan Province of China, where eight cascade dams have been planned or are being constructed. To identify the vegetation composition and structure, we sampled 126 quadrats along the transects arrayed vertically to both side of river channel from the year of 2004 to 2010. We found that the forest, shrub and grass communities were widely spread along the riverside. In low reach watershed of the Lancang-Mekong River, the dominated vegetations were grasses and shrubs which were severely disturbed by human activity. In middle reach of the Lancang-Mekong River, the dry-hot valley vegetation was found in the low valley. At high altitude, the pine forest and semi-evergreen seasonal forest were found. As a result of dam construction and operation, the structure and compositions of riparian vegetation were strongly changed. Some plants declined or disappeared due to the alteration of their habitats. The protection or restoration interventions are urgently needed to mitigate the risk of vegetation damage associated with dam projects along middle and low reach of the Lancang-Mekong River.

From the Himalayan region or the Malay Archipelago:Molecular dating to trace the origin of a fern genus Phymatopteris(Polypodiaceae)

Phymatopteris Pic.Serm.,a derived polypodiaceous fern,is one of the many fern genera that still suffer from nomenclatural confusion.Its generic circumscription and phylogenetic relationships with other selligueoid ferns have been controversial,and its geographic origin,whether in the Himalayan region of continental Asia or in Malay Archipelago,is still unknown.A phylogeny of all selligueoid ferns based on 4 cpDNA(rbcL,trnL-F,rps4 and rps4-trnS) regions indicates that Phymatopteris is not monophyletic.Phymatopteris species are distributed in 5 well-supported clades that can be distinguished with frond-shape and frond-margin characters.All early-divergent species are from the Malaysian Archipelago,while the remaining species are all from the Himalayan region and form a recently diverged group that is largely unresolved,most likely having resulted from an explosive radiation.Divergence-time estimation suggests that the first diversification of selligueoid ferns occurred at ca.27 Ma in the Malaysian Archipelago,followed by migration into the Himalayan region around 20 Ma.The radiation of the Himalayan species occurred mostly within the last 20 million years,within the period of recent major uplifts of the Qinghai-Tibetan Plateau(between the early Miocene and the Pleistocene) and late-Cenozoic global cooling.Our evidence leads us to propose that the Malaysian Archipelago is the ancestral area for Phymatopteris.

Neighborhood effects on the tannin-related foraging decisions of two rodent species under semi-natural conditions

Neighborhood effects on seed predation and dispersal processes are usually seed-characteristic-dependent;however,how seeds with certain characteristics affect the foraging behavior of rodents in relation to other seeds nearby is unclear.Because large differences in seed characteristics between neighboring seeds may lead to significant differences in rodent foraging preferences,we hypothesized that neighborhood effects were more likely to be detected when paired seeds differed in seed characteristics.We investigated the foraging decisions of two rodent species,the red spiny rat Maxomys surifer and the Chinese white-bellied rat Niviventer confucianus,in semi-natural enclosures by presenting them with artificial seeds containing different levels of tannin(0,3%,and 6%tannin).Both rodents showed similar preferences and preferentially consumed high-tannin seeds(6%tannin)and scatter hoarded low-tannin seeds(0 tannin).The scatter hoarding of low-tannin(0 tannin)and high-tannin(6%tannin)seeds was significantly higher when these seeds were neighboring higher-tannin seeds than when they neighbored lowertannin seeds,whereas the scatter hoarding of intermediate-tannin seeds(3%tannin)varied little when they had different neighbors.High-tannin-seed(6%tannin)scatter hoarding was lowest when they neighbored low-tannin seeds(0 tannin),while low-tannin-seed(0 tannin)scatter hoarding was highest when they neighbored high-tannin seeds(6%tannin).Therefore,the seeds that the rodents scatter hoarded were next to(neighbored)seeds that they preferred to eat immediately,and vice versa.Our findings suggest that seed neighborhood effects affect rodent foraging behavior and the relationship between plants and rodents,and may have a profound effect on the regeneration and spatial structure of plant communities.