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337 ecological experiment Preprints

Related keywords
ecological experiment behavioral ecology ecosystem function invertebrate plants terrestrial natural history ecosystem ecology description experimental evolution laboratory statistical freshwater community ecology theoretical multiple vertebrate comparative population ecology method development none of the above ecosystem evolutionary ecology
Please note: These are preprints and have not been peer reviewed. Data may be preliminary.
Lack of evidence for a fine scale magnetic map sense for fall migratory Eastern North...
Patrick Guerra
Adam Parlin

Patrick Guerra

and 2 more

August 12, 2022
How first-time animal migrants find specific destinations remains an intriguing ecological question. Migratory marine species use geomagnetic map cues acquired as juveniles to aide long-distance migration, but less is known for long-distance migrants in other taxa. We test the hypothesis that naïve Eastern North American fall migratory monarch butterflies (Danaus plexippus), a species that possesses a magnetic sense, locate their overwintering sites in Central Mexico using inherited geomagnetic map cues. We examined whether overwintering locations and the abundance of monarchs changed with the natural shift of Earth’s magnetic field from 2004 to 2018. We found that migratory monarchs continued to overwinter at established sites in similar abundance despite significant shifts in the geomagnetic field, which is inconsistent with monarchs using fine scale geomagnetic map cues to find overwintering sites. It is more likely that monarchs use geomagnetic cues to assess migratory direction rather than location and use other cues to locate overwintering sites.
A GRAIN DIET SUPPLEMENTED WITH INSECTS RATHER THAN FRUITS SUPPORTS A MORE ROBUST BODY...
OJODOMO SIMON
Shiiwua Manu

OJODOMO SIMON

and 3 more

August 12, 2022
1. Omnivores utilise dietary sources which differ in nutrients, hence dietary restrictions due to environmental change or habitat alteration should cause nutrient limitations; and thus, deterioration of body condition if omnivory is obligate. 2. We investigated how the body condition of the Village weaver Ploceus cucullatus (weavers), which forages predominantly on grains, responds to insects and fruits deprivation. 3. Forty wild-caught weavers held in aviaries were fed a combination of grains and fruits, or grains and insects ad libitum for eight weeks. We confirmed diet preference by recording the number of foragers on each diet option per minute for one hour and the amount of food left-over after 3 hours of foraging. Fortnightly, we assessed indices of body condition including body mass, pectoral muscle, and fat scores, Packed Cell Volume (PCV) and Haemoglobin Concentration (HBC). We modelled the number of foragers, food left-over and body condition as functions of diet, while accounting for time (weeks) and sex effects. 4. We confirmed grains as the preferred diet and found that males ate more fruits and insects than females. Weavers fed on grains and fruits lost body and pectoral muscle mass and accumulated less fat than those fed on grains and insects. This effect was sex-dependent: females deprived of insects lost more pectoral muscle mass than males of the same group and males but not females, deprived of fruits accumulated more fat reserve than those deprived of insects. PCV and HBC did not differ between diets but increased over the eight weeks. 5. Weavers are likely obligate rather than facultative omnivores, with insects as being a more nutritive supplement than fruits. We conclude that nutrient limitation arising from environmental change or habitat alteration can impair body condition and affect physiological response to environmental seasonality in other obligate omnivores like the weavers.
Allometric Equation for Biomass Estimation of Pouteria adolfi-friederici (Engl.) Baeh...
Abyot Dibaba Hundie
Teshome Soromessa

Abyot Dibaba Hundie

and 2 more

August 12, 2022
Abstract: This study was conducted in Gerba Dima Forest, South Western Ethiopia to formulate allometric equations for Pouteria adolfi-friederici. Prior to collecting data for tree allometry, the study forest was stratified into 3 forest strata based on altitudinal variation. By employing semi-destructive technique, 30 individuals were systematically selected and sampled for measuring biomass along the three forest strata. Based on the data collected, several equations were developed. Before establishing the allometric equation, scatter plots were used to see whether the relationship between independent and dependent variables was linear. Furthermore, several allometric relationships between independent and dependent variables were tested. The best-fit model developed was validated by testing the regression assumptions. AGB was regressed against the various forms of predictors (i.e., DBH, H and WD) and three allometric models showed significant performance (p < 0.05) on their F-test. Among the three allometric equations which showed significant performance, the selection of the best-fit model was conducted based on their P-value, adjusted r2, AIC, RMSE. The two models are nested to the third model and hence the complete model, lnAGB=1.806+1.419×lnDBH+0.628×lnWD, is selected as the best-fit model against the other two nested models since the p-values of coefficients of the complete model are significant (p < 0.05).
Evolutionary footprints of cold adaptation in arctic-alpine Cochlearia (Brassicaceae)...
Marcus Koch

Marcus Koch

August 10, 2022
As global warming progresses, plants may be forced to adapt to drastically changing environmental conditions. Arctic-alpine plants have been among the first to experience the effects of climate change, as regions at high latitudes and elevations are over-proportionally affected by rising temperatures. As a result, cold acclimation and freezing tolerance may become increasingly crucial for the survival of many plants as winter warming events and earlier snowmelt will cause increased exposure to occasional frost. Studying the evolution of cold adaptation allows us to make assumptions about the future responses of different species to climate change. The tribe Cochlearieae from the mustard family (Brassicaceae) offers an instructive system for studying cold adaptation in evolutionary terms, as the two sister genera Ionopsidium and Cochlearia are distributed among different ecological habitats throughout the European continent and the far north into circumarctic regions. By applying an electrolyte leakage assay to leaves, the freezing tolerance of different Ionopsidium and Cochlearia species was assessed by experimentally estimating lethal freezing temperature values (LT50 and LT100), thereby allowing for a comparison of different accessions in their responses to cold. We hypothesized that, owing to varying selection pressures, geographically distant species would differ in freezing tolerance. Despite Ionopsidium being adapted to hot and dry Mediterranean conditions and Cochlearia species preferring cold habitats, all accessions exhibited similar cold responses. Whether this phenomenon has resulted from an evolutionary adaptation of a common ancestor of the two taxa or has evolved from parallel evolution is yet to be investigated. The results presented in this study may, however, indicate that adaptations to different stressors, such as salinity and drought, may confer an additional tolerance to cold; this is because all these stressors induce osmotic challenges, as demonstrated via metabolomic analysis.
Species richness drove selection of individuals within wetlands based on traits relat...
Lucas Deschamps
Raphaël Proulx

Lucas Deschamps

and 5 more

August 09, 2022
Aim: Selection within natural communities has mainly been studied along large abiotic gradient, while the selection of individuals within population should occur locally under the play of biotic filter. To better seize the role of the latter, we postulated that the hierarchal nature of environmental selection and the multiple dimension of species trait space needed to be accounted for. Methods: We replicated a natural species richness gradient (from 2 to 16 species) within four contrasted wetlands (bog, fen, meadow, marsh), sampling functional traits from random individuals in communities. Developing a hierarchical distributional modelling, we analyzed the variation of the mean and dispersion of functional trait space at the ecosystem, community and species levels. Key results: We found that the abiotic differences between wetlands, which shaped a plant productivity gradient, selected species in regards with their leaf nutrient conservation / acquisition strategy. Within ecosystems, plant species richness was a strong driver of trait variation among both communities and species. Among communities, it shaped the selection of individuals according to their space occupation and leaf adaptations to light conditions. Demographically, some species used intraspecific trait variation to maintain equally dense populations, while others used it to become dominant in favorable conditions. Main Conclusions: Within ecosystems, variation in biotic conditions selects individuals along functional dimensions that are independent to the ones selected across ecosystems. Because intraspecific variations of light-related traits are related to demographic responses, it offers a way to link the study of species richness and eco-evolutionary dynamics.
Elevated nitrogen deposition and co-evolutionary history shape competition between an...
Wen-Gang Zhang
Xing-Jiang Song

Wen-Gang Zhang

and 8 more

July 31, 2022
During the range expansion of invasive plants, competitors shared different co-evolutionary history with invasive plants, as well as population differentiation, would have different effects on the response of invaders to global change factors such as increased nitrogen deposition. Disregard the community responses and potential adaptations of invaders during the range expansion might bring misleading answers. To address these challenges, we conducted a greenhouse experiment to explore the synergistic effects between population differentiation during range expansion and competitors on the invasion of Galinsoga quadriradiata in response to increased nitrogen deposition. Competitors (new or old that shared short or long co-evolutionary history with the invader, respectively) were set to compete with the invasive central and edge populations under different nitrogen addition treatments. Galinsoga quadriradiata from the central population (i.e., with longer residence time since invasion) showed significantly higher total mass, reproduction, interspecific competitiveness when compared to the individuals from the edge population, and the magnitude of response to nitrogen addition treatments was larger in the central population when planted in isolation (single-culture). Nitrogen addition promoted growth and reproductive performance of G. quadriradiata in single-culture, in the presence of competitors this effect was weakened. The old competitors acted more effectively than new competitors in inhibiting the invader performance, mainly for the central population. Our results indicate that population differentiation on growth and competitiveness occurred during the range expansion of G. quadriradiata, with the central population displaying higher invasiveness than the edge population. The co-evolutionary history between invasive species and its competitors has been suggested to be probably not in favor of invasive plants, especially for central populations. Our results highlight the synergistic and non-additive role of population differentiation and shared co-evolution history between invasive species and its competitors in the range expansion of invaders in the context of global change factors.
Synergistic regulation between leaf N and P on Vcmax and Jmax of species in subtropic...
Longkang Ni

Ni

July 28, 2022
A document by Longkang Ni, written on Authorea.
Assessing the importance of seed priming for seed germination in Muscari.
IMAN ROHOLLAHI
Narjes Labbaf

IMAN ROHOLLAHI

and 2 more

July 26, 2022
Muscari with absorbing color is a widespread and commercial species. As a pot and bedding bulb flower has excellent adaptability and vigorous growth in late winter and early spring. In our experiment, the quantity and uniformity of Muscari propagation by seed and the importance of seed priming will be measured. The selected M. neglectum populations which already were gathered in our previews research and M. armeniacum were evaluated under separated sulfuric acid (5, 15, and 20 min) and hot water (5, 15, and 20 min) scarification plus 15, 30, and 45 days stratification in a completely randomized design, four replications were planted in separate containers. Seeds of M. armeniacum only germinate (70%) by 15 min sulfuric acid plus 45-day stratification treatments. Based on the analysis of variance and mean comparison data that only were reported in M. neglectum, their seeds optimally germinated by 5 and 15 min sulfuric acid treatment plus 45-day stratification. In conclusion, M. neglectum seeds germination is tuned to take place well in mid-winter under natural conditions; on the other hand, 45 days of lengthy constant stratification and 5 min sulfuric acid priming will accelerate M. neglectum seeds germination.
Screening game in plant–pollinator interactions: compound screening mechanism in flow...
Qin-zheng  Hou
Nurbiye  Ehmet

Qin-zheng Hou

and 5 more

July 26, 2022
The screening mechanism is an important component of the screening game between plants and pollinators, and also as a theoretical framework for understanding the maintenance and drivers of co-evolution by animals and plants. However, no previous studies have investigated the composite screening mechanism in plants from biomechanical and morphological perspectives. Thus, we observed and measured the insects and flower traits in different populations of Delphinium caeruleum J., and compared the operative strength of staminodes with the strength that insects were capable of exerting, as well as the length of the nectar spur and proboscis in insects. The flower traits, insect species, visitor frequency, and efficiency differed among three experimental sites. The strength and proboscis length of the insect visitors matched with the operative strength of staminodes and the nectar spur length, whereas the opposite was found for non-visitors. Our results demonstrate that Delphinium caeruleum J. can screen for efficient pollinator insects through a complex mechanism based on a combination of length screening and biomechanical screening. Pollinators contribute significantly to promoting both the convergence and divergence of flower characteristics, which may be a consequence of plants adapting to local pollinators.
First record of White Eared Kob Kobus kob leucotis in Omo National Park, Ethiopia
Tsyon Asfaw
Mihert Ewenetu

Tsyon Asfaw

and 5 more

July 15, 2022
A document by Tsyon Asfaw, written on Authorea.
Shyer fish are superior swimmers in Siberian sturgeon (Acipenser baerii)
Lingli Xiang
Xiangyuan Mi

Lingli Xiang

and 11 more

July 13, 2022
Differences in individual personality are common amongst animals, which can play an ecological and evolutionary role given links to fitness. Personality affects animal life processes and outputs (e.g., behavior, life history, growth, survival, reproduction), and has become a common theme in animal behavioral ecology research. In the present study, we used Siberian Sturgeon to explore how personality traits of boldness and shyness are related to swimming performance, post exercise recovery and phenotypic morphology. Firstly, our results indicated that the Siberian sturgeon juveniles of shyness were better swimmers, validating evolutionary biology trade-off theory. The critical swimming speed (Ucrit) of the shy groups was higher than that of the bold groups. Secondly, the shy groups were more resilient after exercise fatigue. The swimming fatigue recovery ability, the glucose and lactic acid concentration recovery ability of shy groups were greater than that of bold groups. Thirdly, the shy groups were more streamlined. Compared with bold groups, shy groups had smaller caudate stalk lengths, caudate stalk heights, superior caudal lobes, and inferior caudal lobes. These research results further enrich the theoretical viewpoints of fish behavior biology, more importantly, which provided a good example for studying the relationship between sturgeon’s “personality” and swimming performance.
Local and landscape environmental heterogeneity drive ant community structure in temp...
Antonio J. Pérez Sánchez
Anett Schibalski

Antonio Pérez Sánchez

and 4 more

July 12, 2022
Environmental heterogeneity is an important driver of ecological communities. Here, we assessed the effects of local and landscape spatial environmental heterogeneity on ant community structure in temperate semi-natural upland grasslands of Central Germany. We surveyed 33 grassland sites representing a gradient in elevation and landscape composition. Local environmental heterogeneity was measured in terms of variability of temperature and moisture within and between grasslands sites. Grassland management type (pasture vs. meadows) was additionally included as a local environmental heterogeneity measure. The complexity of habitat types in the surroundings of grassland sites were used as a measure of landscape environmental heterogeneity. As descriptors of ant community structure, we considered species composition, community evenness, and functional response traits. We found that extensively grazed pastures and within-site heterogeneity in soil moisture at local scale, and a high diversity of land cover types at the landscape scale affected ant species composition by promoting nest densities. Ant community evenness was high in wetter grasslands with low within-site variability in soil moisture and surrounded by a less diverse landscape. Fourth-corner models revealed that ant community structure response to environmental heterogeneity was mediated mainly by worker size, colony size, and life history traits related with colony reproduction and foundation. We discuss how within-site local variability in soil moisture and low intensity grazing promote ant species densities, and highlight the role of habitat temperature and humidity affecting on community evenness. We hypothesize that a higher diversity of land cover types in a forest-dominated landscape buffers less favorable environmental conditions for ant species establishment and dispersal between grasslands. We conclude that spatial environmental heterogeneity at local and landscape scale plays an important role as deterministic force in filtering ant species and, along with neutral processes (e.g. stochastic colonization), in shaping ant community structure in temperate semi-natural upland grasslands.
Recovery from heat-induced infertility -- a study of reproductive tissue responses an...
Berta Canal
Claudia Fricke

Berta Canal

and 1 more

July 12, 2022
The predicted temperature increase caused by climate change is a threat to biodiversity. Male reproduction is particularly sensitive to elevated temperatures resulting in sterility. Here we investigate temperature induced changes in reproductive tissues and the fertility reduction in male Drosophila melanogaster. We challenged males during development and either allowed them to recover or not in early adulthood, while measuring several determinants of male reproductive success. We found significant differences in recovery rate, organ sizes, sperm production and other key reproductive traits among males from our different temperature treatments. Spermatogenesis and hence sperm maturation was impaired before reaching the upper thermal sterility threshold. While some effects were reversible, this did not compensate the earlier damage imposed. Surprisingly, developmental heat stress was damaging to accessory gland growth and female post mating responses mediated by seminal fluid proteins were impaired regardless of the possibility of recovery. We suggest that sub-lethal thermal sterility and the subsequent fertility reduction is caused by a combination of malfunctioning reproductive traits: inefficient functionality of the accessory gland and alteration of spermatogenesis.
Ecological significance of deceptive pollination in Papilionanthe teres
tingting Yang
xiang Zhou

tingting Yang

and 1 more

July 05, 2022
Though some hypotheses have obtained theoretical and empirical supports, it remains largely unknown in the aspect that how deception increases orchid fitness. This study used food-deceptive Papilionanthe teres as experimental material to explore the ecological significance of orchid deceptive pollination. Deception together with obvious pollinarium bending increases P. teres fitness by means of decreasing geitonogamy under the natural conditions. The proportions of full seeds, single fruit weight and seed weight per fruit after self-pollination and nectar addition were significantly lower than that after cross-pollination and natural conditions (all p < 0.05). Seed viability (seed growth and development rate) after cross-pollination and natural condition were significantly higher than that after self-pollination and nectar addition (all p < 0.05). However, there was no significant difference in all the above parameter values of fruits and seeds between cross-pollination and natural conditions (all p > 0.05). These results confirmed that P. teres has high level of genetic load, and self-fertilization or geitonogamy will cause serious inbreeding depression. These conclusions support the outcrossing hypothesis that ecological significance of P. teres deception is to promote outcrossing and improve the ability of the offspring to adapt to the environment.
Diversity, relative abundance and distribution of medium and large mammals in Mago Na...
Girma Mengesha

Girma Mengesha

June 23, 2022
The objective of this study was to investigate diversity, relative abundance, and distribution of medium and large mammals in Mago National Park (MNP), Southern Ethiopia. Data collection was conducted during dry and wet seasons. A systematic sampling design was used to establish line transects along the three main habitat types, namely: Woodland, Acacia savanna, and Riverine forest. A total of 45 line transects were established through the habitats, varing in length from 1.5 to 5 km, depending on the size of the habitat. Twenty-eight medium and large mammals species were recorded in the area belonging to 8 families and 5 orders. Order Artiodactyla had the highest number of species (14 species), followed by Carnivora (8 species), whereas Perissodactyla and Proboscidea were represented by one species each. During both seasons, the highest species diversity (H’ = 2.81, and H’=2.96) was recorded in woodland habitat, but the lowest ( H’ =2.5 and H’= 2.67) in riverine forest. In terms of abundance, Tragelaphus imberbis 1773±86 (12%) was the most abundant species, while Vulpes chama was the least abundant species 104 ±13 that contributed less than 1% of the total. Most of the mammals species occurred in woodland habitat as compared to the other habitat types. Seasonal variation in abundance (number) of individuals of medium and large mammals was significantly different (X2 = 91.651, df =1, p<0.05). However, variation in species composition was not significant (X2 = 0.018, df = 1, P<0.05). It can be concluded that, Mago National Park harbour high species diversity of medium and large mammals. Conservation efoforts that could suatain the high diversity pf the species in the area in needed to main the diversity.
Structure and characteristics of plant-frugivore network in Guilin Botanical Garden
GuoHai Wang
Yang Huang

GuoHai Wang

and 7 more

June 22, 2022
The interaction between plants and frugivores plays a critical role in sustaining ecosystem function and community diversity, but little is known about the structure of interaction networks between fruit plants and frugivore birds in urban green spaces. We observed the interactions between plants and birds throughout the year in the Guilin Botanical Garden and assessed the characteristics of the total plant-frugivore and seasonal networks. We also analyzed the relationship between the network roles of species and ecological traits to explore the structure and characteristics of the plant-frugivore network. The interactions between a total of 14 frugivore birds and 13 fruit plant species were analyzed in the study area, the autumn and winter interaction connections contributed 38.79% and 33.15% to the total network, respectively. The specialization (H2´), and interaction evenness (E2) of the network were higher in spring and summer than that in autumn and winter. However, connectance (C), nestedness, and interaction diversity (H2) were contrary to the specialization and interaction evenness of the network. Compared to the networks (N=1000) generated by the null model, the observed network exhibited lower connectance (C), interaction diversity(H2), interaction evenness (E2), and higher nestedness and specialization (H2´). A correlation analysis combining ecological traits and network roles showed that plants with black fruit had higher species strength, whereas the other traits of plants and birds were not significantly correlated with their network parameters.
Evolution of population dynamics following invasion by a non-native predator
Sigurd Einum
Emil Ullern

Sigurd Einum

and 3 more

June 21, 2022
Invasive predatory species are frequently observed to cause evolutionary responses in prey phenotypes, which in turn may translate into evolution of the prey’s population dynamics. Research has provided a link between rates of predation and the evolution of prey population growth in the lab, but studies from natural populations are rare. Here we tested for evolutionary changes in population dynamics parameters of zooplankton Daphnia pulicaria following invasion by the predator Bythotrephes longimanus into Lake Kegonsa, Wisconsin, US. We used a resurrection ecological approach, whereby clones from pre- and post-invasive periods were hatched from eggs obtained in sediment cores and were used in a 3-month growth experiment. Based on these data we estimated intrinsic population growth rates (r) and carrying capacities (K) using theta-logistic models. We found that post-invasion Daphnia maintained a higher r and K under these controlled, predation-free laboratory conditions. Thus, whereas previous experimental evolution studies of predator-prey interactions have demonstrated that genotypes that have evolved under predation have inferior competitive ability when the predator is absent, this was not the case for the Daphnia. Given that our study was conducted in a laboratory environment and the possibility for genotype-by-environment interactions, extrapolating these apparent counterintuitive results to the wild should be done with caution. However, barring such complications, we discuss how selection for reduced predator exposure, either temporally or spatially, may have led to the observed changes. This scenario suggests that complexities in ecological interactions represents a challenge when predicting the evolutionary responses of population dynamics to changes in predation pressure in natural systems.
New evidence for seed transmission of reptiles in arid areas of China
Zhenyuan Duan
Lei Shi

Zhenyuan Duan

and 1 more

June 20, 2022
Abstract: Diet and trophic niche of Teratoscincus roborowskii was analyzed by pellets analysis technique. A total of 263 pellets of Teratoscincus roborowskii were collected from the Turpan Botanic Garden in Turpan City from July to Octobor, 2016, . Food composition and proportion of Teratoscincus roborowskii were identified by comparative analysis. The number of food components in the fecal samples was identified, and the numeric frequency, biomass ratio and frequency of occurrence of each component were counted and then the monthly Shannon-wiener diversity index, Shannon evenness index and diet niche width were analyzed. The results show that the Teratoscincus roborowskii mainly feed on insects and caper fruit in the Turpan Botanic Garden. Insects are the most common food for the Teratoscincus roborowskii, the frequency of occurrence which in each month is the largest; caper fruit was the most food intake in July and August, and that of insects is the most one on September and October. There are some differences in the composition of food in different months, which may be related to changes of food availability. The results of the feeding habit analysis show that the Teratoscincus roborowskii may play an active role in the dispersal of caper seed.
“Realistic strategies” and neutral processes drive the community assembly based on le...
Lijuan Zhao
Wenhua Xiang

Lijuan Zhao

and 10 more

June 16, 2022
We sought to assess effect of plant environmental adaptation strategies and evolutionary history and quantify the contribution of ecological processes to community assembly by measuring functional traits and phylogenetic composition in local forest community. We selected 18 dominant tree species in a Lithocarpus glaber–Cyclobalanopsis glauca evergreen broad-leaved forest and measured nine leaf functional traits and phylogenetic data of each species. We analyzed the variation in traits and trade-off relationships, tested phylogenetic effects on leaf functional traits, explored the influence of phylogeny and environment on leaf functional traits, and distinguished the relative effects of spatial and environmental variables on functional traits and phylogenetic compositions. The results showed the following: (i) Leaf traits had moderate intraspecific variation, and significant interspecific variation existed especially among life forms. (ii) Significant phylogenetic signals were detected only in leaf thickness and leaf area. The correlations among traits both supported “the leaf economics spectrum” at the species and community levels, and the relationships significantly increased or only a little change after removing the influence of phylogeny, which showed a lack of consistency between the leaf functional trait patterns and phylogenetic patterns. We infer the coexistent species tended to adopt “realism” to adapt to their habitats. (iii) Soil total potassium and phosphorus content, altitude, aspect, and convexity were the most critical environmental factors affecting functional traits and phylogenetic composition. Total environmental and spatial variables explained 63.38% of the variation in functional trait composition and 47.96% of the variation in phylogenetic structures. Meanwhile, the contribution of pure spatial factors was significantly higher than that of the pure environment. Neutral- theory-based stochastic processes played dominant roles in driving community functional trait assembly, but niche-theory-based determinative processes such as environmental filtering had a stronger effect on shaping community phylogenetic structure at a fine scale.
Crop diversity and susceptibility of crop fields to elephant raids in eastern Okavang...
Tiroyaone Albertinah Matsika
Gaseitsiwe Masunga

Tiroyaone Albertinah Matsika

and 7 more

June 08, 2022
Abstract 1. Elephants frequently raid farmers’ crops within their ranges in Africa and Asia. This can have a large impact on agricultural productivity and food security for farmers. 2. Previous studies have examined susceptibility of crop fields to elephant raids using field characteristics such as field size and proximity to water sources. However, there are limited studies investigating how different crop types, individually and in their combinations influence crop susceptibility to elephant raiding. Also, spatio-temporal patterns in elephant crop raids in agro-ecological landscapes have not been extensively examined. 3. This study utilised data collected from crop fields raided by elephants between 2008 and 2018. Data on crops grown, the number of crop-raiding incidences for each crop, and elephant raiding incidences were recorded for each field assessed. Incidence risks (IR) and field risk value (RV) were computed using an adaptive epidemiological approach. 4. The results showed that elephant crop raiding incidents varied significantly amongst crop types, and over space and time (P<0.0001). Cereal crops (millet: Eleusine conaracana, maize: Zea mays) incurred a higher number of crop raiding incidents compared with leguminous crops (cowpea: Vigna unguiculata; groundnut: Arachis hypogea). Field RVs significantly varied depending on which crop was present in the field. There was a significant negative correlation between the number of crop types and the susceptibility of the field to raiding (R2 = -0.680, P<0.0001). 5. Our results suggest that the susceptibility of the fields to elephant raids could be minimised by selecting crop types and combinations less susceptible to elephant damage, thus enhancing food security for local subsistence farmers. Keywords: crop raiding, crop species, incidence risks, field risk value, food security, human-elephant conflict
Plant-soil feedback from eastern redcedar (Juniperus virginiana) inhibits the growth...
Leland Bennion
David Ward

Leland Bennion

and 1 more

June 06, 2022
1. The encroachment of woody plants into grasslands is an ongoing global problem that is largely attributed to anthropogenic factors such as climate change and land management practices. Determining the mechanisms that drive successful encroachment is a critical step towards planning restoration and long-term management strategies. Feedbacks between soil and aboveground communities can have a large influence on the fitness of plants and must be considered as potentially important drivers for woody encroachment. 2. We conducted a plant-soil feedback experiment in a greenhouse between eastern redcedar Juniperus virginiana and four common North American prairie grass species. We assessed how soils that had been occupied by redcedar, a pervasive woody encroacher in the Great Plains of North America, affected the growth of big bluestem, little bluestem smooth brome, and western wheatgrass over time. We evaluated the effect of redcedar on grass performance by comparing the height and biomass of individuals of each grass species that were grown in live or sterilized conspecific or redcedar soil. 3. We found that redcedar created a negative plant-soil feedback that limited the growth of two species. These effects were found in both live and sterilized redcedar soils, indicating redcedar may exude an allelochemical into the soil that limits grass growth. 4. Synthesis. By evaluating the strength and direction of plant-soil feedbacks in the encroaching range, we can further our understanding of how woody pants successfully establish in new plant communities. Our results demonstrate that plant-soil feedback created by redcedar inhibits the growth of certain grass species. By creating a plant-plant interaction that negatively affects competitors, redcedars increase the probability of seedling survival until they can grow to overtop their neighbors. These results indicate plant-soil feedback is a mechanism of native woody plant encroachment that could be important in many systems yet is understudied.
Modeling Habitat Suitability of Hippophaerhamnoides L. Using MaxEnt under Climate cha...
Xiaohui HE
Si J. H.

Xiaohui HE

and 8 more

May 31, 2022
Hippophaerhamnoides is widely known for its important ecological, economic, and social benefits. It is known as the pioneer plant of soil and water conservation, with homology in food and medicine. Here we used occurrence data and environmental (climate and soil) variables to simulate and predict the habitat distribution for H. r. sinensis and H. r. trkestanica in China, both at the current time and in the 2050s (2041-2060). Our aim was to analyze the dominant factors effecting its distribution using MaxEnt and the spatial analysis of geographic information system. The results indicated that H. r. sinensis is mainly distributed in Shaanxi, Shanxi, Sichuan, Qinghai, Gansu, Ningxia, Tibet, and Inner Mongolia, and is mainly affected by bio13 (precipitation of the wettest month), bio11 (mean temperature of the coldest quarte) and bio3 (Isothermality). The suitable habitat of H. r. trkestanica is mainly distributed in Xinjiang, and Tibet, and is mainly affected by bio13 (precipitation of the wettest month), bio2 (mean diurnal range) and bio15 (precipitation seasonality). Although, the two subspecies tend to expand and migrate toward lower latitude under future climate scenarios, there are some differences. H. r. sinensis will migrate westward, while H. r. trkestanica will migrate eastward as a whole. They have a high stability of suitable habitat and are not at risk of extinction in the future. The study’s findings help to clarify the resource reserve of Hippophaerhamnoides L. in China, which will help to guide the protection of wild resources and to popularize artificial planting in suitable areas, and provides scientific basis for the protection of ecological environment.
Influence of edaphic conditions on aboveground biomass in areas post-mining in the Co...
Harley Quinto Mosquera
Jhon Jerley Torres Torres

Harley Quinto Mosquera

and 2 more

May 30, 2022
Mining is one of the main drivers of deforestation of tropical forests. This activity affects the storage of aboveground biomass of these ecosystems; and, therefore, its ability to contribute to the mitigation of global climate change. The influence of soils on the aboveground biomass of areas post-mining in the Colombian Pacific was evaluated. For this, plots were established in areas post-mining and with different successional ages (12-15 years, 30-35 years and mature forest). The aboveground biomass and physicochemical parameters of the soil were measured. A aboveground biomass of 15.58 t ha-1, 35.17 t ha-1, and 178.32 t ha-1 was recorded at 12-15 years, 30-35 years and mature forest, respectively. The aboveground biomass was positively correlated with organic matter (OM), calcium (Ca), magnesium (Mg), CICE, total nitrogen (N) and silt; whereas, with sand, aluminum (Al) and potassium (K) content the relationship was negative. It was evidenced that the relationship between aboveground biomass and soils was different in each successional age. When evaluating the changes of aboveground biomass and soils in the successional, it was observed that the aboveground biomass and total N increased with the recovery time; while the P and K decreased with succession. On the other hand, the contents of OM, Mg, Al, Ca and CICE, showed curvilinear tendencies, since they increased in the first stages, and then in the advanced successional stages they decreased. In summary, the results showed that the aboveground biomass of areas post-mining was limited by multiple soil nutrients.
Effect of grazing intensity on plant–soil C:N:P stoichiometry within a desert grassla...
Wan Tao

Wan Tao

May 30, 2022
Background and aims High-intensity grazing in Mongolian grasslands has led to the general deterioration of biodiversity and ecosystem functioning. Abundant evidence shows that grazing affects the structure and function of grassland ecosystems, especially under overgrazing. Methods We examined the effects of three grazing intensities (0, 1.92, and 3.08 sheep ha-1 a-1) on plant commu-nities, plant and soil C, N and P contents, and plant and soil C:N:P stoichiometry in a desert grassland in different years. Results Grazing did not affect plant coverage, richness, or N:P, and the plant community biomass, litter bio-mass and C:N and C:P were highest under a zero grazing intensity. Soil C:N changed with the year and grazing intensity. However, soil C:P and N:P were higher in 2018 than in 2016 and 2017. Conclusions Our study suggested that grazing promoted the flow of N between plants and the soil, especially at 3.08 sheep ha-1 a-1. Under grazing stress, plants maintained the potential for compensatory growth. Further-more, N was shown to be the limiting fertilizer component for plants growing in this area among the three grazing intensities.
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