为探讨地形对林下灌草层植物生物量的影响，该研究采用嵌套设计法在东北虎豹国家公园调查了138个密林下样地共1 685个植物样方，通过嵌套方差分析与有序逻辑斯蒂回归模型对林下灌草层植物生物量受地形的影响进行了分析。结果表明：(1)不同坡位之间，谷底的灌草层植物生物量高于坡上，坡上高于坡下(P<0.01);不同坡向之间，阴坡灌草层植物生物量低于阳坡及平地(P<0.01),后二者间无显著差异；不同坡度之间，平坡灌草层植物生物量高于陡坡，陡坡高于缓坡(P<0.01)。(2)坡位与坡向的交互作用显著，坡下平地、坡上平地、坡上阳坡与谷底的所有坡位灌草层植物生物量最高，坡下阴坡、坡下阳坡及坡上阴坡之间无显著差异。(3)研究区现行状态下，有序逻辑斯蒂回归结果显示，灌草层植物生物量在不同海拔、坡位及坡向坡度组合下不同。坡位、坡向及坡度对林下灌草层植物生物量有显著影响，3个坡位等级间谷底最高而坡下最低，3个坡度等级间陡坡最高而缓坡最低，不同坡向比较，阴坡最低。(4)在不排除人为干扰、森林放牧的现实情况下，谷底、陡坡地带灌草层植物生物量概率最高。该研究结果可为准确估计东北虎豹国家公园林下灌草层植物对虎豹猎物种群的承载力提供重要参考，从而为濒危虎豹的保护和管理提供科学依据。

Large herbivores are particularly susceptible to changes in quantity and quality of forage resources, in turn constraining populations of large and threatened carnivores. Key prey species for Amur tigers (Panthera tigris altaica) and leopards (P. pardus orientalis), Siberian roe deer (Capreolus pygargus) have a spatial distribution which is greatly influenced by habitat quality across topographic regions. In this study, we used 138 camera-trap stations to record the abundance and distribution of Siberian roe deer in the mountains (n = 88) and valleys (n = 50) of the Northeast China Tiger and Leopard National Park, and we examined the impact of overstory structure and understory food resources on the relative abundance index (RAI) of the deer. We use generalized linear mixed models (GLMM) with negative binomial distributions, with the response variable of RAI of either of deer on the mountain or in the valley. We included canopy cover (CC), tree richness (TR) and basal area (BA) from overstory structure and mass of shrub layer (SM), mass of grasses and sedges (GM), forbs mass (FoM), ferns mass (FeM) and understory mass (UM) from understory food as fixed effects. We found that RAI of roe deer was significantly higher for the mountain than the valley. For the mountain, BA, TR and FoM were found to have a significant positive effect on roe deer, while CC showed a negative effect. In the valley, BA had a significant positive effect on roe deer, while SM showed a negative effect. Roe deer appeared to trade-off overstory structure with understory food resources, especially BA and FoM, which may lead them to prefer mountains over valleys in the national park. These findings will assist in understanding the distribution of roe deer populations in Northeast China Tiger and Leopard National Park, and may suggest more effective conservation and management strategies for the forest ecosystems of Northeast China.

Plants enhance nutrient uptake in heterogeneous nutrient environments through selective root placement. Many studies have documented that plants grow better under heterogeneous than under homogeneous nutrient distribution, but comprehensive syntheses are relatively few. In a meta-analysis, we examined the effects of patch scale and contrast on plant responses by synthesizing the effects of nutrient heterogeneity on root foraging and plant growth in 131 comparative studies. Plant responses to nutrient heterogeneity were phylogenetically conserved, and the response in shoot biomass was significantly correlated with the response in root biomass but not with root foraging precision. Root precision depended on the competition regime, and plants had lower precision in interspecific than in conspecific competition. Community-level growth was significantly promoted by nutrient heterogeneity and was less variable than individual-level responses. Along with increasing patch scale, overall shoot and root responses of individuals increased but root foraging precision declined. In addition, moderate patch contrast induced the highest root responses. Our results indicate that plants optimize nutrient acquisition from heterogeneous patches mainly through increasing root growth, and plant communities exploit heterogeneous nutrients more effectively than individuals. Understanding the roles of patch attributes in nutrient-heterogeneity effects may help in designing fertilization practices to promote productivity and conserve biodiversity.

野生东北虎(Panthera tigris altaica)和东北豹(Panthera pardus orientalis)是中国东北和俄罗斯远东地区森林生态系统食物链的顶级物种,是森林生态系统健康、生态系统良好结构的指示物种.林下灌草层片是东北虎、东北豹所食猎物的主要生境和食物来源.因此调查中国吉林珲春地区次生林、林下灌草层生物量,对蒙古栎重要值大于50%的162条样线和646个1 m2样方进行分析.野外调查将样方的放牧强度分为对照组、轻度放牧组和放牧组,样方内的植物分为灌木/树叶、禾草/莎草、其他禾草和蕨类4个类别.以放牧强度为自变量,以4种植物类别的生物量为响应变量,进行嵌套多元方差分析.结果表明,森林放牧显著减少林下灌木层植物的生物量.从食物链的角度出发,为维持生态系统结构平衡和野生动植物种群健康,建议科学放牧,降低放牧强度和密度.

The North Chinese leopard (Panthera pardus japonensis), the least-known big cat, disappeared in most historical range for decades, following the development of modern civilization. Unfortunately, we have scarce knowledge about the status of this big cat so far, apart from anecdotal reports. In this study, we investigated density, distribution, and habitat use of the leopard, the apex predator, in a complex forest landscape in the Loess Plateau. We used a camera-trapping network to obtain population estimates for leopards over 2 years through spatially explicit capture-recapture models. Our results, based on maximum likelihood and Bayesian/MCMC methods, reveal that the largest wild population of the leopard was found widely distributed in remnant forests in central Loess plateau. The population is increasing in our study area, and the density of leopards (1.70 (SE = 0.48) - 2.40 (SE = 0.67)/100 km2 ) is higher than other areas of China. According to the analysis of 2 seasonal occupancy models, prey species drive partially the leopard habitat use, predicting that the big cat thrives from the recovery of prey community. However, human disturbances, especially oil wells, seem to have negative impacts on the habitat use of leopards. Specifically, it is necessary to have joint efforts by the government and researchers to improve human disturbances management and prey species population density, as well as strengthen the investment in research on the North Chinese leopard, which could all further strengthen protection ability and ensure the long-term survival of this species.

东北虎和东北豹主要捕食马鹿、梅花鹿、狍及野猪等大中型有蹄类动物,而这些有蹄类的生存依赖森林灌草层的植食性食物资源,形成了东北亚温带森林生态系统完整的啃食食物链(gazing food chain)主体.本研究通过对建设中的东北虎豹国家公园东部地区有蹄类栖息地的灌草层植物进行本底调查,获得有蹄类动物的食物资源基线数据.2015年及2016年的生长季,在东北虎豹国家公园东部,随机选择141个样地嵌套496条样线,1 948个样方,对不同森林结构(郁闭林及开阔生境,开阔生境包括林窗、林缘和河岸带)的灌草层植物生物量、食物类别组成(嫩枝叶、禾莎草、杂类草和蕨类)及碳、氮含量进行调查分析.研究结果显示:灌草层生物量在开阔生境显著高于郁闭林下(94.91 g/m2vs.30.15 g/m2),达到3.15倍.三种开阔生境下的灌草层食物资源类别组成差异显著,在林窗内以嫩枝叶占优势,在林缘以杂类草占优势,在河岸带以蕨类占优势.灌草层中杂类草和嫩枝叶平均氮含量高,杂类草碳含量低、C/N低;四类植物热值均超17 kJ/g,其中嫩枝叶最高.嫩枝叶、杂类草占优势的高生物量(生物量大于40 g/m2)斑块占郁闭林下的16％、占开阔生境的50％左右,可能是精食者(browser)的取食热点区域.建议在未来国家公园建设中,在合适地段保留一定的开阔生境,为梅花鹿等食草动物补充高质量的灌草层食物资源斑块,促进有蹄类动物种群发展,并以此为基础恢复虎豹种群.

ContextUnderstanding how large carnivore guilds survive in human-dominated landscapes is key to inform strategies for their conservation in the face of global carnivore declines. Amur tigers and leopards are recovering across the China-Russia border. However, knowledge is limited about competitive interactions between two large cats in Northeast Asia.ObjectivesTo assess the spatial, temporal and combined spatiotemporal behavioral mechanisms potentially allow co-occurrence between tigers and leopards in a human-dominated forest landscape.MethodsBased on a large-scale camera-trapping data set in Northeast China, we used three different approaches for quantifying spatiotemporal associations: one spatial method (two-species occupancy model), one strictly temporal method (activity pattern overlap), and one spatiotemporal method based on multi-response permutation procedures at shared camera trap sites.ResultsSpatially, leopards showed no avoidance of the areas highly used by dominant tigers, but their diurnal activity pattern was significantly different from that of tigers. Spatiotemporal overlap analysis showed fine-scale behavioral avoidance when both co-occurred at camera locations, which further facilitates sympatry. Tigers spatially overlapped with humans, but they were less active during the day when human activities were more frequent. In areas with high cattle density, low occurrence of tigers and leopards may reflect the absence of sika deer, an important prey item for both species.ConclusionsThis study provides the first empirical evidence that tigers do not limit leopard distributions, at least in our study area in Northeast Asia. Our results highlighted temporal segregation, not large-scaled spatial avoidance, as a key mechanism promoting coexistence of two large carnivores. Understanding these fine- spatial scale (i.e., camera locations) interactions between sympatric carnivores can help devise management strategies for predator guilds in human-dominated landscapes, currently a major global challenge.

Aims Root decomposition plays an important role in biogeochemical cycles in terrestrial ecosystems. However, there is still controversy on whether low-order (finer) or high-order (coarser) roots decay faster. Previous studies on root decomposition often used dried root samples, and the dehydrating process may influence the results. In this study, we aimed to examine the decomposability of low- and high-order roots and whether initial moisture status would influence their decomposition. Methods We carried out a one-year litterbag experiment for roots of a subtropical tree species Liquidambar formosana. Roots for the decomposition were divided into low- (1st and 2nd orders) and high-order (3rd and 4th orders) classes, and were dried or kept fresh before being buried into the soil. Results We found that low-order roots were decomposed slower (half the rate of high-order roots in terms of mass loss), and the content of soluble carbohydrates was the main influencing factor. We also found that drying prior to decomposition facilitated the decomposition of high-order roots during the early stage by 10%. Conclusions Our study suggests that litter carbon quality, particularly soluble carbohydrate content, is the major driver for root decomposition, and that previous studies using dried root samples might have overestimated short-term root decomposition.

森林放牧是中国东北虎豹国家公园内影响最广泛且强度最大的人类干扰之一.研究放牧对有蹄类动物食物资源的影响,是估算当前状态下东北虎和东北豹主要猎物承载力的关键,可为国家公园的管理提供有效的科学依据.本研究于2016年在中国东北虎豹国家公园东部的牧场和非牧场区域分层抽取50个林下样地设置围栏对照实验,于2017年生长季进行灌草层植被调查(每个样地的围栏与对照各随机调查3个1 m×1 m的样方,共调查300个植物样方),并应用红外相机技术获取对照样地内有蹄类动物丰富度和活动情况,研究放牧对研究区灌草层植物及动物的影响.研究结果显示:在生长季内,森林放牧显著降低林下灌草层植物生物量(减少约24％),牧场样地的嫩枝叶显著降低.除禾草外,牧场样地中其他类别植物的氮含量均显著高于非牧场样地(平均超出非牧场样地25％).非牧场样地梅花鹿的相对丰富度指数(RAI)显著高于牧场样地,而狍与野猪的相对丰富度指数(RAI)在两类样地间没有显著差别.研究结果表明,东北虎豹国家公园东部森林放牧,减少了有蹄类动物灌草层食物资源,降低了有蹄类动物的多度.建议停止森林放牧,恢复有蹄类动物栖息地.

The daily activities of animals are influenced by various factors, including their physiological adaptations and preferred habitat distributions, as well as prey availability and human disturbances. For felids, the main drivers of activity patterns appear to be prey availability and anthropogenic disturbances, as suggested by previous studies. In this study, we explore a set of variables that influence the activity patterns of Amur tigers (Panthera tigris altaica) in Jilin and Heilongjiang Provinces in north-east China near south-western Primorsky Krai, Russia. This area is currently the only occupied tiger habitat in China. Prey availability (e.g. wild boar, sika deer and roe deer), human disturbances (e.g. human activity, distance to human settlements and intense forest livestock grazing), and habitat structure were analysed. Our results revealed crepuscular and nocturnal activity of Amur tigers. Although the temporal overlaps between the tigers and their prey species were high, the spatial overlap indices were low. Although the presence of tigers decreased near human settlements, tigers showed a preference for walking along roads. Tigers also avoided high-elevation coniferous and mixed hardwood forests. Overall, our results indicated that (1) tigers spatially and temporally avoided human disturbances and tigers respond behaviourally to human disturbances and (2) human disturbances may determine the activity of Amur tigers in north-east China. In the future, to address conflicts between tigers and local humans and to improve tiger conservation, conservation planning should incorporate the spatio-temporal activity patterns of tigers and humans.

Large carnivore populations are globally threatened by human impacts. Better protection could benefit carnivores, co-occurring species, and the ecosystems they inhabit. The relationship between carnivores and humans, however, is not always consistent in areas of high human activities and is often mediated through the effects of humans on their ungulate prey. To test assumptions regarding how prey abundance and humans affect carnivore occurrence, density, and daily activity patterns, we assessed tiger-prey-human spatiotemporal patterns based on camera-trapping data in Hunchun Nature Reserve, a promising core area for tiger restoration in China. Our study area contained seasonally varying levels of human disturbance in summer and winter. We used N-mixture models to predict the relative abundance of ungulate prey considering human and environmental covariates. We estimated tiger spatial distribution using occupancy models and models of prey relative abundance from N-mixture models. Finally, we estimated temporal activity patterns of tigers and prey using kernel density estimates to test for temporal avoidance between tigers, prey, and humans. Our results show that human-related activities depressed the relative abundance of prey at different scales and in different ways, but across species, the relative abundance of prey directly increased tiger occupancy. Tiger occupancy was strongly positively associated with the relative abundance of sika deer in summer and winter. The crepuscular and nocturnal tigers also apparently synchronized their activity with that of wild boar and roe deer. However, tigers temporally avoided human activity without direct spatial avoidance. Our study supports the effects of humans on tigers through human impacts on prey populations. Conservation efforts may not only target human disturbance on predators, but also on prey to alleviate human-carnivore conflict.

(1) Background: Plant roots respond to nutrients through root architecture that is regulated by hormones. Strong inter-specific variation in root architecture has been well documented, but physiological mechanisms that may control the variation have not. (2) Methods: We examined correlations between root architecture and hormones to seek clues on mechanisms behind root foraging behavior. In the green house at Beijing Normal University, hydroponic culture experiments were used to examine the root responses of four species—Callistephus chinensis, Solidago canadensis, Ailanthus altissima, Oryza sativa—to two nitrogen types (NO3− or NH4+), three nitrogen concentrations (low, medium, and high concentrations of 0.2, 1, and 18 mM, respectively) and two ways of nitrogen application (stable vs. variable). The plants were harvested after 36 days to measure root mass, 1st order root length, seminal root length for O. sativa, density of the 1st order laterals, seminal root number for O. sativa, the inter-node length of the 1st order laterals, and root hormone contents of indole-3-acetic acid, abscisic acid, and cytokinins (zeatin + zeatinriboside). (3) Results: Species differed significantly in their root architecture responses to nitrogen treatments. They also differed significantly in hormone responses to the nitrogen treatments. Additionally, the correlations between root architecture and hormone responses were quite variable across the species. Each hormone had highly species-specific relationships with root responses. (4) Conclusions: Our finding implies that a particular root foraging behavior is probably not controlled by the same biochemical pathway in all species.

Ectomycorrhizal (EM) networks provide a variety of services to plants and ecosystems include nutrient uptake and transfer, seedling survival, internal cycling of nutrients, plant competition, and so on. To deeply their structure and function in ecosystems, we investigated the spatial patterns and nitrogen (N) transfer of EM networks using 15 N labelling technique in a Mongolian scotch pine ( Pinus sylvestris var. mongolica Litv.) plantation in Northeastern China. In August 2011, four plots (20 × 20 m) were set up in the plantation. 125 ml 5 at.% 0.15 mol/L 15 NH 4 15 NO 3 solution was injected into soil at the center of each plot. Before and 2, 6, 30 and 215 days after the 15 N application, needles (current year) of each pine were sampled along four 12 m sampling lines. Needle total N and 15 N concentrations were analyzed. We observed needle N and 15 N concentrations increased significantly over time after 15 N application, up to 31 and 0.42%, respectively. There was no correlation between needle N concentration and 15 N/ 14 N ratio (R 2 = 0.40, n = 5, P = 0.156), while excess needle N concentration and excess needle 15 N/ 14 N ratio were positively correlated across different time intervals (R 2 = 0.89, n = 4, P < 0.05), but deceased with time interval lengthening. Needle 15 N/ 14 N ratio increased with time, but it was not correlated with distance. Needle 15 N/ 14 N ratio was negative with distance before and 6th day and 30th day, positive with distance at 2nd day, but the trend was considerably weaker, their slop were close to zero. These results demonstrated that EM networks were ubiquitous and uniformly distributed in the Mongolian scotch pine plantation and a random network. We found N transfer efficiency was very high, absorbed N by EM network was transferred as wide as possible, we observed N uptake of plant had strong bias for 14 N and 15 N, namely N fractionation. Understanding the structure and function of EM networks in ecosystems may lead to a deeper understanding of ecological stability and evolution, and thus provide new theoretical approaches to improve conservation practices for the management of the Earth’s ecosystems.

The Amur leopard Panthera pardus orientalis is one of the most endangered cat subspecies in the world. The rare leopard is sympatric with Amur tiger Panthera tigris altaica and their prey in human dominated landscape. To conserve the felid species, it is important to understand the activity patterns of Amur leopards, including its interactions with Amur tigers, prey, and human activities. We used a data set from 163 camera traps to quantify the spatial-temporal overlap between Amur leopards, Amur tigers, prey species, and human disturbances (e.g., humans presence on foot, vehicles, domestic dogs, and cattle grazing) from January to December 2013 in the Hunchun Nature Reserve, NE China. Our results indicated that leopards were more active in daytime and twilight; the seasonal spatial-temporal overlaps between leopards and tigers were lower than that between leopards and their prey species. Human activities and cattle grazing could influence the spatial distribution and activity patterns of the leopards, and therefore, the conservation actions should focus on reduction of human disturbances to minimize the impacts to Amur leopard activity patterns.

We analyzed the scats of Amur tigers and Amur leopards, and examined their annual and seasonal food habits in Northeast China to comprehend their coexistence. Wild boar had the highest annual and seasonal consumption frequencies by the tigers, while both roe deer and sika deer were mostly preyed by the leopards annually. The three species appeared to be the key preys in terms of high proportion of consumed biomass by the two felids. Our data also revealed numerous mid-sized carnivores and small mammals included in the two felids' food list. We used the relative abundance and biomass density estimation in prey density estimation to calculate the prey preferences of tigers and leopards, and both methods confirmed that Amur tigers strongly preferred wild boar. However, preference estimations of Amur leopards were not consistant, or even opposite to one another from the two methods. The results of the study suggested that prey preference of predators is largely determined by body size of the prey species. Variation in diet composition of the two felids suggests that resource partitioning may contribute to their coexistence.

Abstract There is little direct evidence for effects of soil heterogeneity and root plasticity on the competitive interactions among plants. In this study, we experimentally examined the impacts of temporal nutrient heterogeneity on root growth and interactions between two plant species with very different rooting strategies: Liquidambar styraciflua (sweet gum), which shows high root plasticity in response to soil nutrient heterogeneity, and Pinus taeda (loblolly pine), a species with less plastic roots. Seedlings of the two species were grown in sandboxes in inter‐ and intraspecific combinations. Nutrients were applied in a patch either in a stable (slow‐release) or in a variable (pulse) manner. Plant aboveground biomass, fine root mass, root allocation between nutrient patch and outside the patch, and root vertical distribution were measured. L. styraciflua grew more aboveground (40% and 27% in stable and variable nutrient treatment, respectively) and fine roots (41% and 8% in stable and variable nutrient treatment, respectively) when competing with P. taeda than when competing with a conspecific individual, but the growth of P. taeda was not changed by competition from L. styraciflua. Temporal variation in patch nutrient level had little effect on the species’ competitive interactions. The more flexible L. styraciflua changed its vertical distribution of fine roots in response to competition from P. taeda, growing more roots in deeper soil layers compared to its roots in conspecific competition, leading to niche differentiation between the species, while the fine root distribution of P. taeda remained unchanged across all treatments. Synthesis. L. styraciflua showed greater flexibility in root growth by changing its root vertical distribution and occupying space of not occupied by P. taeda. This flexibility gave L. styraciflua an advantage in interspecific competition.

Plants are thought to be able to regulate local root growth according to its overall nutrient status as well as nutrient contents in a local substrate patch. Therefore, root plastic responses to environmental changes are probably co-determined by local responses of root modules and systematic control of the whole plant. Recent studies showed that the contrast in nutrient availability between different patches could significantly influence the growth and death of local roots. In this study, we further explored, beside nutrient contrast, whether root growth and death in a local patch are also affected by relative root quantity in the patch. We conducted a split-root experiment with different splitting ratios of roots of Canada goldenrod (Solidago canadensis) individuals, as well as high- (5× Hoagland solution versus water) or low- (1× Hoagland solution versus water) contrast nutrient conditions for the split roots. The results showed that root growth decreased in nutrient-rich patches but increased in nutrient-poor patches when more roots co-occurred in the same patches, irrespective of nutrient contrast condition. Root mortality depended on contrasts in both root quantity and nutrients: in the high-nutrient-contrast condition, it increased in nutrient-rich patches but decreased in nutrient-poor patches with increasing root proportion; while in the low-nutrient-contrast condition, it showed the opposite trend. These results demonstrated that root growth and death dynamics were affected by the contrast in both nutrient availability and root quantity between patches. Our study provided ecological evidence that local root growth and death are mediated by both the responses of root modules to a nutrient patch and the whole-plant nutrient status, suggesting that future work investigating root production and turnover should take into account the degree of heterogeneity in nutrient and root distribution.

Predator-prey relationship indicates the status of wildlife conservation. Identifying preys and their contribution to the diets of tigers are important for making conservation meaningful. The main objective of this research was to investigate the distribution pattern of tigers and availability of their preys in the Shuklaphanta Wildlife Reserve (SWR), Far west Nepal. This research mainly focused on distribution and identification of scats, determination of prey species and factors affecting their selection. This study was conducted in SWR of 305 km2 area in Kanchanpur district, lowland, Far west Nepal. It was gazatted as Royal Shuklaphanta Wildlife Reserve in 1973. Data were collected through direct field observations and Participatory Rural Appraisal (PRA) method. Relationship between tigers and preys was determined through scats analysis. Data were analyzed with the help of Scatman and vegan through R Software. Prey and habitat selection analysis showed that chital (Axis axis) preferred sal (Shorea robusta) forests while barking (Muntiacus muntjak) and swamp (Rucervus duvauceli) deer were abundant in river sides and fireline/mixed forests respectively. Then, identified eight prey species from 65 scats of which six percent had double preys and 94% single preys. Chital constituted 30% and swamp deer 17% of the total tiger’s diet. The population density of chital was the highest (54.10 animals/km2) followed by common langur (25.27 animals/km2), swamp deer (21.50 animals/km2) and hog deer (16.30 animals/km2). Chital, hog deer and langur were preyed significantly (P ≤ 0) higher by tigers indicating positive selection of these species. Swamp deer was preyed significantly low (P > 0) indicating negative selection probably due to its large size. Tigers prefer medium to slightly large prey species like chital of about 55 kg body weight compared to large sized swamp deer and sambar weighing more than 150 and 210 kg respectively in SWR. Since, both tigers and preys are endangered due to poaching and habitat loss, regular monitoring of them is essential to develop the tiger conservation plan.

Point placement of urea is an efficient technology to improve urea use efficiency in transplanted rice (Oryza sativa L.), but it is largely unknown how nutrient composition in the point placement and the distance from placement site to the plant influence rice root distribution and growth, nutrient uptake, and rice grain yield. A controlled greenhouse experiment was conducted using both N- and P-deficient soil with point placement of N only or N and P together (N + P) at a distance close to or far from the plant, in comparison to an N-spilt application and a no-N control. Both nutrient composition and distance significantly affected rice root growth. Compared with the N point placement, the N + P point placement led to smaller root length and mass densities, higher specific root length (SRL) around the placement site, smaller root system, higher straw mass and grain yield, and higher N and P uptake. The difference between the N + P and N point placements was greater when close to the plant than when far from the plant. It is suggested that higher SRL around the placement site is essential for improving nutrient uptake and rice grain yield, and simultaneous point placement of N and P has a synergistic effect on rice growth.