Changes In Plant Communities Research Articles

Effects of different types of vegetation cover on soil microorganisms and humus characteristics of soda-saline land in the Songnen Plain.

In the soda-saline grasslands of the Songnen Plain, Jilin Province, China, the prohibition of grazing has led to significant changes in plant communities and soil properties. However, the intricate interplay between soil physical and chemical attributes, the soil microbial community, and their combined influence on soil humus composition remains poorly understood. Our study aimed to evaluate the impact of natural vegetation restoration on soil properties, microbial community diversity, and composition in the soda-saline soil region of the Songnen Plain. We conducted assessments of soil physical and chemical properties, analyzed community diversity, and composition at a soil depth range of 0-20 cm. The study covered soils with dominant soda-saline vegetation species, including Suaeda glauca Bunge, Puccinellia chinampoensis Ohwi, Chloris virgata Swarta, Phragmites australis (Clay.), Leymus chinensis (Trin.), and Tzvelev. We compared these vegetated soils to bare land devoid of any plants. We found that soil organic content (SOC) in vegetation restoration areas was higher than in bare land, with SOC content varying between 3.64 and 11.15 g/kg in different vegetated areas. Notably, soil pH emerged as a pivotal factor, explaining 11.4% and 12.2% of the variance in soil bacteria and fungi, respectively. There were correlations between SOC content and the relative abundance of specific microbial groups, with Acidobacteria and Mortierella showing a positive correlation, while Actinobacteria, Gemmatimonadetes, and Ascomycota exhibited significant negative correlations with SOC. The disparities in SOC composition and content among the soda-saline vegetation types were primarily attributed to variations in pH. Consequently, reducing soil pH is identified as a critical step in the process of vegetation restoration in soda-saline land. Prohibiting grazing has the potential to increase soda-saline SOC content and enhance microbial diversity, with Leymus chinensis and Phragmites australis showing particularly promising results in terms of higher SOC carbon content and microbial diversity.

Plant Community Prediction Based on Lotka-Volterra Model and Statistical Analysis

The change process of plant communities is an important issue involving botany, environmental science and system science. This paper mainly studies the state changes of plant communities under irregular weather cycles, and establishes a dynamic model of species interaction based on Lotka-Volterra equations. The Euler method, statistical analysis are used to solve the problem. we extend the basic Lotka-Volterra model to the generalized Lotka-Volterra model, which can describe the change of a community with multiple species. Based on this, by introducing parameters such as drought intensity, species sensitivity to drought, pollution level and habitat reduction into the equations, a model for predicting the change of plant community status under the influence of irregular weather cycles is obtained. The statistical method is creatively used to do Sensitivity analysis for the model. The results show that: (1) pollution and habitat reduction do not affect the advantages of highly drought-resistant plants, but extend the gain range of species number on plant community stability. (2) the influence of some negative factors on the gain interval is the comprehensive result of the influence of two opposite factors, competition intensity and species diversity.

Transformation of phosphorus forms and its regulation on phosphorus availability across differently degraded marsh soils

AbstractSoil phosphorus (P) is a vital nutrient that controls wetland productivity and ecological functions. However, the effects of soil P forms on P availability during wetland degradation are relatively unknown. We selected differently degraded marshes, including non‐degraded marsh (NDM), lightly degraded marsh (LDM), moderately degraded marsh (MDM), and heavily degraded marsh (HDM), to research the changes in soil P forms by sequential chemical extraction and its regulation on P availability in the Zoige Plateau, China. The results showed that compared with the 0–30 cm soil layers of NDM, the main changes in total P concentration were a significant increase of 31.6%–44.2% in LDM and MDM, and the available P concentration increased by 28.7%–76.2% in LDM and MDM but decreased by 4.0%–47.5% in HDM with a lower P activation coefficient. Marsh degradation increased the concentration of soil dicalcium phosphates, P occluded in iron hydroxides, and organic P from the entire profile by 46.7%–137.7%, 31.7%–49.3%, and 78.1%–82.1%, respectively, while it decreased that of iron oxide surface adsorbed P and apatite P by 17.2%–32.2% and 15.3%–27.8%, respectively. Soil available P was mainly related to organic P and P non‐occluded in iron oxide minerals, which might also be a non‐negligible direct source of available P. The transformation from apatite P to organic P was an important regulatory mechanism of P availability in soils during marsh degradation. This study revealed the transformation trajectory of soil P forms owing to soil desiccation accompanied by plant community changes and overgrazing during alpine marsh degradation, and the risk of P limitation in HDMs with low soil available P. For degraded marsh restoration, some measures for improving P availability should be implemented in the future, such as grazing exclusion and the application of organic fertilizer.

Mechanical forest restoration treatments stimulate understory plants in the Colorado Front Range

Restoration efforts are underway in dry conifer forests across the western United States to increase their resilience to wildfire and other disturbances. Because such treatments typically decrease overstory density and homogeneity, they can also drive changes in the understory plant community. Past studies of post-treatment changes in understories have found variable results over short time frames and across regions, highlighting the need to study longer-term, region-specific responses. We investigated whether mechanical restoration treatments benefited understory plants in dry conifer forests of the Colorado Front Range, and what biotic and abiotic variables modified understory plant responses in treated areas. We analyzed data collected 1–2 years pre-treatment, 1–2 years post-treatment, and 4–6 years post-treatment in 168 plots, which were distributed across 8 sites and 16 pairs of treated and nearby untreated areas. Treatments were implemented by removing trees with heavy machinery or hand tools (i.e., thinning). By the time treatments were 4–6 years old, native understory plant cover was 1.7 times higher in treated compared to untreated plots, and native richness was 1.1 times higher. Heightened cover and richness values in treated plots were not driven by a single native plant functional group, but by a large portion of the native community; long-lived, graminoid, vegetatively spreading, and non-vegetatively spreading plants all had higher cover in treated plots, while short-lived, long-lived, forb, graminoid, and non-vegetatively spreading plants had higher richness in treated plots. Non-native plants showed 3.1 times higher cover and 4.4 times higher richness in treated compared to untreated plots at 4–6 years post-treatment, but were present at very low levels (e.g., ≤ 0.5% mean cover in either treatment). Greater native plant cover and richness at 4–6 years post-treatment were associated with lower overstory basal areas that resembled 19th-century forest structural conditions for the landscape. Contrary to expectations, a long-term measure of moisture availability (i.e., 30-year average climatic water deficit) was not a strong predictor of native cover or richness in treated plots 4–6 years post-treatment; rather, they were better predicted by moisture availability during the spring months prior to sampling. Overall, the consistent and enduring stimulation of cover and richness of native understory plants after mechanical treatments, with only limited invasion from non-native species, illustrates the important benefits of ongoing restoration activities in dry conifer forests of the Colorado Front Range.

Impact of Drought on Ecohydrology of Southern California Grassland and Shrubland

Through their rooting profiles and water demands, plants affect the distribution of water in the soil profile. Simultaneously, soil water content controls plant development and interactions within and between plant communities. These plant-soil water feedbacks might vary across plant communities with different rooting depths and species composition. In semiarid environments, understanding these differences will be essential to predict how ecosystems will respond to drought, which may become more frequent and severe with climate change. In this study, we tested how plant-soil water feedbacks responded to drought in two contrasting ecosystem types—grassland and shrubland—in the coastal foothills of southern California. During years 5–8 of an ongoing precipitation manipulation experiment, we measured changes in plant communities and soil moisture up to 2 m depth. We observed different water use patterns in grassland and shrubland communities with distinct plant functional types and water use strategies. Drought treatment did not affect perennial, deep-rooted shrubs because they could access deep soil water pools. However, mid-rooted shrubs were sensitive to drought and experienced decreased productivity and die-off. As a result, water content actually increased with drought at soil depths from 50–150 cm. In grassland, biomass production by annual species, including annual grasses and forbs, declined with drought, resulting in lower water uptake from the surface soil layer. An opportunistic “live fast, die young“ life strategy allowed these species to recover quickly once water availability increased. Our results show how drought interacts with plant community composition to affect the soil water balance of semiarid ecosystems, information that could be integrated into global scale models.

Warming‐induced functional shifts in the decomposer community interact with plant community compositional shifts to impact litter decomposition

Abstract Climate warming is altering plant and soil microbial communities, with important implications for ecosystem processes like litter decomposition. As warming alters plant community composition, the quality of litter will change. Further, shifts in microbial community activity and/or composition will alter microbial function. However, it is not yet completely understood how these shifts will interact to drive decomposition. We explored how changes in plant and microbial communities interact to influence litter decomposition using a 15‐year‐old grassland warming experiment. Previous studies within this system have shown that warming shifted the microbial community in ways that accelerate litter decomposition while simultaneously shifting the plant community in ways that may slow decomposition. Specifically, warming increased abundance of Sorghastrum nutans, while decreasing abundance of the previously dominant Schizachyrium scoparium. Using a series of lab‐based microcosm experiments, we examined the rate at which eight common grasses and, separately, varying abundances of S. nutans and S. scoparium decomposed. Using litter and soil from the warming experiment, we then incubated soils from warmed or control plots with different abundances of S. nutans and S. scoparium in a reciprocal design. We found S. nutans to be the slowest‐decomposing grass in our system. Further, decomposition slowed as S. nutans increased and S. scoparium decreased. When examining the interaction of plant and microbial communities, decomposition was generally greater early in our experiment as the relative abundance of S. scoparium increased. However, soil microbial community origin and litter composition interacted significantly. Specifically, decomposition increased with greater relative abundance of S. scoparium on soils derived from control plots, while litter composition did not shape rates of decomposition on soils from warmed plots. The influence of litter species on decomposition waned in the later stages of the experiment when decomposition was driven by microbial community origin. These results suggest that warming‐induced changes in microbial community function may interact with changes in plant litter composition to mitigate the impacts of warming on rates of decomposition. This emphasizes the importance of considering concurrent warming‐induced changes in both plant and microbial communities on ecosystem processes like decomposition. Read the free Plain Language Summary for this article on the Journal blog.

Combined effects of aboveground herbivores and belowground microorganisms on dynamics of soil nematode communities in grassland mesocosms

Nematodes are the most abundant animals in soil. They are active in all trophic levels and functionally important for plant growth and plant diversity. Nematode community structure not only can be directly influenced by other belowground organisms such as soil microbes via trophic interactions, but also indirectly by aboveground organisms like herbivores through plant-mediated aboveground-belowground linkages. In the current study, by introducing foliar-feeding aphids (Rhopalosiphum padi) and soil microbial suspensions to mesocosms planted with 12 grassland plant species and where an identical nematode community was introduced in all mesocosms, we aimed to investigate the individual and combined effects of soil microbes and foliar herbivores on the dynamics of plant and the soil nematode community. Introduction of aphids reduced shoot and root biomass of the plant community, and in particular decreased the proportional biomass of the dominant plant species Anthoxanthum odoratum, resulting in a higher diversity of the plant community but without affecting the nematode communities. In contrast, the inoculation of soil microbes did not significantly alter plant composition structure, but it reduced the total nematode abundance and enhanced nematode diversity by increasing the abundance of carnivorous nematodes and decreasing the abundance of plant-feeding nematodes. There were no significant aboveground-belowground interactions in the current study via effects of aphids on the soil nematode communities or via soil microbes and nematodes on the plant communities. Collectively, our study indicates that soil nematode communities in grasslands can be strongly steered by soil microbial inoculations but weakly influenced by aboveground herbivory despite its resulting changes in plant communities, notwithstanding that these effects appeared to be largely independent.

Plant Community Changes Based on The Lotka-Volterra Model

Globally, ecosystem functions are threatened by repeated droughts and declining plant diversity. Due to frequent droughts, the species in the plant community show different adaptions towards the extreme weather conditions. The aim of this report is to explore how the plant community changes over time. Considering the growth law of population, establish the model of precipitation and plant growth rate based on the Logistic function. Moreover, considering the competition and interaction between populations, this paper chooses the Lotka-Volterra model and adapt it, then use the improved Euler method to obtain numerical solutions of these nonlinear ordinary differential equations of plant population over time under the interaction of multiple populations. The observations are obtained: For the population of a plant community, when the rainy season intersects with droughts, the decline rate of the population at the inflection point slows down, the continuity of population change is interrupted. And the plant population shows an increasing trend in the rainy season, and a decreasing trend in droughts.

Multiple dimensions of biodiversity mediate effects of temperature on invertebrate herbivory in a montane grassland

Invertebrate herbivores are important and diverse, and their abundance and impacts will likely shift under climate change. Yet, past studies of invertebrate herbivory have documented highly variable responses to changing temperature, making it challenging to predict the direction and magnitude of these shifts. One explanation for these responses is that changing environmental conditions drive concurrent changes in plant communities and herbivore traits. The impacts of changing temperature on herbivory might therefore depend on how temperature combines and interacts with characteristics of plant and herbivore communities. To test this, we surveyed damage to leaves by invertebrate herbivores on 4400 plant individuals in 220 sampling plots along a 1101 m elevational gradient. Increasing temperature drove community‐level herbivory via at least three overlapping mechanisms: increasing temperature directly reduced herbivory, indirectly affected herbivory by reducing plant‐community phylogenetic diversity, and indirectly affected herbivory by altering the effects of plant‐community functional and phylogenetic diversity on herbivory. Consequently, increasing plant functional diversity reduced herbivory in colder environments while increasing plant phylogenetic diversity increased herbivory in warmer environments. Moreover, different herbivore feeding guilds varied in their response to temperature and plant community composition. These results indicate that, even along a single elevation gradient in a single year, a variety of mechanisms can concurrently drive herbivory, thereby supporting the hypothesis that a universal response of herbivory to changing environmental conditions is unlikely to exist. Instead, our results highlight the importance of considering both plant and herbivore community context to predict how climate change will alter invertebrate herbivory.

Successional Changes in Vegetation Communities near Mine Pits

This study investigates demutational changes in plant communities of phosphorite mines between 2005 and 2021. A total of 23 plant species were initially found in the surveyed areas in 2005, while 68 species were identified in spring 2021. The plant communities were categorized into five different groups, with the older communities (No. I and II) exhibiting richer vegetation and greater diversity. Community No. III comprised various cereals, legumes, orchid plants, and mosses. Dominant species in community No. I included Betula pubescens, Carpinus betulus, Quercus robur, and Picea obovata, while community No. II featured Juniperus communis, Larix sibirica, Pinus sylvestris, and Abies sibirica. Erosion was observed in community No. V on slopes of different ages. The study also found changes in physicochemical indices, such as increased organic matter concentration and decreased pH value (4.9). The basal respiration rate of the pit soil was low (around 0.4 mg CO2/m2/h), and carbonate content ranged from 0.06 to 0.9%. This study presents novel data on the dynamics of species composition, plant community structure, and physicochemical soil parameters in human-altered habitats, thereby contributing to the expansion of our knowledge of vegetation recovery and evolution in such environments.

Vegetation structural shift tells environmental changes on the Tibetan Plateau over 40 years

Structural information of grassland changes on the Tibetan Plateau is essential for understanding alterations in critical ecosystem functioning and their underlying drivers that may reflect environmental changes. However, such information at the regional scale is still lacking due to methodological limitations. Beyond remote sensing indicators only recognizing vegetation productivity, we utilized multivariate data fusion and deep learning to characterize formation-based plant community structure in alpine grasslands at the regional scale of the Tibetan Plateau for the first time and compared it with the earlier version of Vegetation Map of China for historical changes. Over the past 40 years, we revealed that (1) the proportion of alpine meadows in alpine grasslands increased from 50% to 69%, well-reflecting the warming and wetting trend; (2) dominances of Kobresia pygmaea and Stipa purpurea formations in alpine meadows and steppes were strengthened to 76% and 92%, respectively; (3) the climate factor mainly drove the distribution of Stipa purpurea formation, but not the recent distribution of Kobresia pygmaea formation that was likely shaped by human activities. Therefore, the underlying mechanisms of grassland changes over the past 40 years were considered to be formation dependent. Overall, the first exploration for structural information of plant community changes in this study not only provides a new perspective to understand drivers of grassland changes and their spatial heterogeneity at the regional scale of the Tibetan Plateau, but also innovates large-scale vegetation study paradigm.

Ecosystem resilience to invasion and drought: Insights after 24 years in a rare never-grazed grassland.

Understanding the resilience of ecosystems globally is hampered by the complex and interacting drivers of change characteristic of the Anthropocene. This is true for drylands of the western US, where widespread alteration of disturbance regimes and spread of invasive non-native species occurred with westward expansion during the 1800s, including the introduction of domestic livestock and spread of Bromus tectorum, an invasive non-native annual grass. In addition, this region has experienced a multi-decadal drought not seen for at least 1200 years with potentially large and interacting impacts on native plant communities. Here, we present 24 years of twice-annual plant cover monitoring (1997-2021) from a semiarid grassland never grazed by domestic livestock but subject to a patchy invasion of B. tectorum beginning in ~1994, compare our findings to surveys done in 1967, and examine potential climate drivers of plant community changes. We found a significant warming trend in the study area, with more than 75% of study year temperatures being warmer than average (1966-2021). We observed a native perennial grass community with high resilience to climate forcings with cover values like those in 1967. In invaded patches, B. tectorum cover was greatest in the early years of this study (1997-2001; ~20%-40%) but was subsequently constrained by climate and subtle variation in soils, with limited evidence of long-term impacts to native vegetation, contradicting earlier studies. Our ability to predict year-to-year variation in functional group and species cover with climate metrics varied, with a 12-month integrated index and fall and winter patterns appearing most important. However, declines to near zero live cover in recent years in response to regional drought intensification leave questions regarding the resiliency of intact grasslands to ongoing aridification and whether the vegetation observations reported here may be a leading indicator of impending change in this protected ecosystem.

Correction to: Post-Restoration Plant Community Changes in Grazed and Ungrazed Seasonal Wetlands in Florida

Correction to: Post-Restoration Plant Community Changes in Grazed and Ungrazed Seasonal Wetlands in Florida

Study on the succession of plant communities under the influence of drought

Drought has a strong impact on the growth of plant populations, and the number of different species in a plant community plays an important role in the drought adaptation of the community's progeny. In this paper, a mathematical model is developed to analyze how the number of different species in a plant community under a long-term irregular drought cycle is adaptive to drought in future generations, and thus how the plant community benefits from it. This paper uses biomass to quantify the growth of plant populations and changes in plant communities, and uses a large amount of visual data for visual analysis. First, a logistic growth model of plant population biomass change is developed based on temperature accumulation, precipitation and interspecific competition as influencing factors. The correlation coefficients were then obtained using the collected plant population biomass to predict the changes in total plant biomass and species richness, and the interspecific competition model was then used to calculate the values of total community biomass after final stabilization based on logistic, and the system of differential equations was solved using the Runge-Kutta Methods was finally concluded that the biomass of the community after final stabilization showed a positive correlation with the number of species and species type, and showed a strong positive correlation with species type and a weak positive correlation with species number.

Climate change impacts flowering phenology in Gongga Mountains, Southwest China

Flowering phenology of plants, which is important for reproductive growth, has been shown to be influenced by climate change. Understanding how flowering phenology responds to climate change and exploring the variation of this response across plant groups can help predict structural and functional changes in plant communities in response to ongoing climate change. Here, we used long-term collections of 33 flowering plant species from the Gongga Mountains (Mt. Gongga hereafter), a biodiversity hotspot, to investigate how plant flowering phenology changed over the past 70 years in response to climate change. We found that mean flowering times in Mt. Gongga were delayed in all vegetation types and elevations over the last 70 years. Furthermore, flowering time was delayed more in lowlands than at high elevations. Interestingly, we observed that spring-flowering plants show earlier flowering times whereas summer/autumn plants show delayed flowering times. Non-synchronous flowering phenology across species was mainly driven by changes in temperature and precipitation. We also found that the flowering phenology of 78.8% plant species was delayed in response to warming temperatures. Our findings also indicate that the magnitude and direction of variation in plant flowering times vary significantly among species along elevation gradients. Shifts in flowering time might cause trophic mismatches with co-occurring and related species, affecting both forest ecosystem structure and function.

Regeneration and plant community change of the iris-forbs subtaiga larch forest affected by clear cutting and fires in Eastern Khuvsgul of Mongolia

This paper presents the research results on the main characteristics of mensuration, regeneration, and plant cover change 36 years after clear-cutting and 3 times repeated fires in the subtaiga larch forest of Eastern Khuvsgul are included. Iris-forbs subtaiga larch forests were replaced by sedge-forbs meadow community with few larch-birch trees after the clear-cutting and fire. Natural regeneration of larch forest is insufficient. After clear-cutting and repeated fires, similarity indexes compared with control forest in the successional years ranged from 52-65 percent for species composition and 22.5-39.11 for coenotic percentage, showing the succession and regeneration of Iris-forbs subtaiga larch forests tend to delay. Нэлэнхүй огтолсоны дараа давтан түймэрт өртсөн Зүүн Хөвсгөлийн цахилдаг-алаг өвст тайгархаг шинэсэн ойн сэргэн ургалт, ургамал бүлгэмдлийн өөрчлөлт Хураангуй. Энэхүү өгүүлэлд мод огтлоод 36 жил болсон, 3 удаагийн давтан түймэрт өртсөн Зүүн Хөвсгөлийн тайгархаг шинэсэн ойн таксацийн үндсэн үзүүлэлт, ойн сэргэн ургалт, ургамал бүрхэвчийн хөдлөлзүйн судалгааны үр дүнг оруулав. Цахилдаг-алаг өвст тайгархаг шинэсэн ой нь мод огтлолт, түймрийн дараа цөөн тооны хус, шинэс бүхий улалж-алаг өвст нугын бүлгэмдлээр солигдож, шинэс модны байгалийн сэргэн ургалт хангалтгүй явагдаж байна. Эх ойтой харьцуулсан төсөөтэй байдлын коэффициент нь огтлолт, давтан түймрийн дараах сукцессийн жилүүдэд зүйлийн бүрэлдэхүүний хувьд 52-65 хувь байхад ценозийн оролцоогоор 22.5-39.11 хувийн хооронд хэлбэлзэж байгаа нь цахилдаг-алаг өвст тайгархаг шинэсэн ойн ургамал бүлгэмдлийн сукцесс, сэргэн ургалтын явц удааширч буйг харуулж байна. Түлхүүр үгс: тайгархаг ой, шинэс, хус, төсөөтэй байдлын коэффициент, ойн сэргэн

Long-term under-vine coverage by spontaneous vegetation changed plant community and soil dynamics without impacting yield at two South Australian vineyards

Under-vine management practices have traditionally consisted of herbicide applications or cultivation to manage weeds, thus limiting competition for resources with grapevines. However, increasing awareness of detrimental impacts of herbicides and cultivation on agricultural landscapes are shifting practices towards alternative options, including an unmanaged under-vine area where spontaneous vegetation proliferates. How this practice may affect the suite of soil, water, and nutrient relations and corresponding grapevine performance in a Mediterranean climate in the long-term is relatively unknown. Thus, this study utilised a unique opportunity to explore how undisturbed under-vine spontaneous vegetation compared to traditional herbicide (Eden Valley, loamy sand soil) or cultivation (McLaren Vale, silty loam soil) practices at two commercial vineyards. After five years of treatments, assessments were made on under-vine plant community and soil dynamics, grapevine responses, and juice composition. At Eden Valley, the spontaneous vegetation changed the plant community by increasing total plant coverage and biomass, while at McLaren Vale there was a lesser effect; however, the plant communities at both sites were similarly dominated by perennial grasses compared to higher proportions of broad-leaf, fast-growing species in the traditional herbicide and cultivation treatments. Soil water and nutrient availability were decreased by spontaneous vegetation in Eden Valley, while in McLaren Vale, the spontaneous vegetation enhanced soil phosphorus, water infiltration, and increased organic carbon by 40%. In Eden Valley, spontaneous vegetation decreased juice yeast available nitrogen; yet phenolics, anthocyanins, and total soluble solids were higher. At both sites, there was no significant impact of maintaining under-vine spontaneous vegetation on yields, however it decreased pruning weights at Eden Valley, while no effects were quantified on pruning weights or juice composition at McLaren Vale. We demonstrate that in the long-term, maintaining undisturbed spontaneous vegetation as an alternative to using herbicides or cultivation in the under-vine row can benefit the vineyard agroecosystem, while not adversely impacting grapevine yields depending on vineyard soil type and target winemaking outcomes.

Scavenger and herbivore functional role impairment modulates changes in plant communities following mass mortality events

Abstract Mass mortality events (MMEs) of wildlife are increasingly frequent and may destabilize communities. MMEs provide a unique ecological context because they simultaneously produce a resource pulse that is sometimes coupled with the loss or severe impairment of functional roles such as predation or herbivory. Moreover, these effects are complicated by global declines in obligate vertebrate scavengers. We designed an experiment to measure the relative importance of bottom‐up (nutrient addition) and top‐down (impairment of obligate scavenger and herbivore functional roles) forces experienced during MMEs on the local plant community. Increasing carrion biomass shifted local plant assemblages from the original state promoting plants more resistant to soil disturbance (i.e. annual plants), but this effect was unique to carrion as the same amount of macronutrients entering the system did not affect the plant community. This may indicate that the effects of carrion are primarily driven by interactions with consumers rather than bottom‐up processes. Additionally, restricting obligate vertebrate scavenger access to increasing amounts of carrion biomass shifted the net effects of the carrion on the plant community by limiting perennial vines. Impairment of the herbivore functional role released plants from top‐down control, increasing plant growth and survival. Our experiment indicates that top‐down forces may have strong effects on plant communities following MMEs. As such, the global increase in wildlife MMEs may have broad consequences on ecological communities, not only on the species affected. Read the free Plain Language Summary for this article on the Journal blog.

Post-Restoration Plant Community Changes in Grazed and Ungrazed Seasonal Wetlands in Florida

Post-Restoration Plant Community Changes in Grazed and Ungrazed Seasonal Wetlands in Florida

Responses of soil bacterial and fungal communities to altered precipitation in a desert steppe.

To investigate the response mechanisms of soil bacterial and fungal communities to the changes of preci-pitation in a desert steppe of Ningxia, we conducted a three-year precipitation control experiment following completely randomized design. There were five treatments, natural precipitation (T0), 50% less in precipitation (T1), 25% less in precipitation (T2), 25% more in precipitation (T3) and 50% more in precipitation (T4). By using Illumina high-throughput sequencing and bioinformatics analysis, we investigated the effects of increased and decreased precipitation on soil bacterial and fungal communities, and examined the correlations between soil physicochemical properties, plant communities and soil bacterial and fungal communities. The result showed that the richness of soil bacteria and fungi was highest in the T4 treatment. In addition, the relative abundance of Chloroflexi, the predominant phyla of soil bacteria was more sensitive to precipitation change. However, the relative abundance of only Ascomycota, a rare fungal taxon, responded to precipitation changes. Results of redundancy analysis showed that the first two axes accounted for 92.8% and 87.4% of the total variance for soil bacterial and fungal community composition, respectively. Precipitation and soil pH were the most important environmental factors driving changes in soil bacterial diversity and community composition. On the one hand, precipitation had a direct positive effect on bacterial diversity and community composition. On the other hand, precipitation changed pH by affecting soil moisture, which in turn had a significant indirect effect on bacterial diversity and community composition. Plant community biomass, plant species richness, and soil pH were the most influential environmental factors affecting fungal diversity and community composition. Precipitation had no direct effect on soil fungal community, but had a significant indirect effect by changing plant community richness and soil pH. The response mechanisms of bacterial and fungal communities in soil differed significantly under different precipitation regimes in the desert grasslands of Ningxia.