Functional Types Research Articles

Drivers of plant biodiversity on cemeteries in the Ruhr Metropolitan Region (W Germany)

Cemeteries are biodiversity hotspots in urban areas, while the drivers of their floristic diversity are poorly understood. We investigated 153 cemeteries in the western Ruhr Metropolitan Region and generated comprehensive species lists of wild plants. Altogether, we found 964 species, equivalent to 53.6% of the flora known from the region. Cluster analysis revealed five distinct cemetery types based on their species composition and prevalence. Subsequently, we used ANOVAs to relate the most effective environmental descriptors identified with a CCA to the five clusters, thus revealing the drivers of species composition. Two of the main clusters had clear regional foci, which could be explained by soil types, while the third main cluster included most of the large cemeteries with many different habitat types, and encompassed sites from the entire study region. Here, the number of species is highest. Two smaller clusters included old historic and Jewish cemeteries, respectively, which were characterized by a smaller number of neophytes and heat indicators. Through the various functional types, the cemeteries contribute to the biodiversity of urban areas like the Ruhr Metropolitan Region and thus counteract the floristic homogenization of cities.

Laser-induced reconfigurable wavefront control with a structured Ge2Sb2Te5-based metasurface

Phase change materials have been widely exploited in active metasurfaces due to their large index contrast. Despite recent advances in phase-change metasurfaces, it remains a challenge to integrate diverse reconfigurable optical functionalities into a single metasurface. Here, we demonstrate an effective strategy to realize reconfigurable wavefront control by combining a Ge2Sb2Te5-rod array with laser writing technology. Through arbitrarily modifying the position and power of laser source, the laser writing process helps to realize site-selective and multi-level phase change of Ge2Sb2Te5 rods. Due to multi-level switching for optical properties of Ge2Sb2Te5 material, the Ge2Sb2Te5-rod array offers complete phase control and high amplitude modulation. Subsequently, various optical devices are designed in numerical simulation, including a phase-only hologram, dynamic meta-deflectors, a grayscale image and a perfect absorber. The structured Ge2Sb2Te5-based metasurface with the combination of laser writing technology offers an effective way to explore various types of optical functionalities in the same device.

Bottom–up propagation of synoptic wind intensification and relaxation in the planktonic ecosystem of the South Senegalese Upwelling Sector

ABSTRACT Synoptic intensification or relaxation of upwelling favorable winds are major sources of variability in eastern boundary upwelling systems. This study aims to investigate their impact on the planktonic ecosystem of the South Senegalese Upwelling Sector (SSUS), located south of the Cape Verde peninsula over a wide and shallow continental shelf. Numerical experiments using a three-dimensional coupled physical–biogeochemical model with four plankton functional types simulated the response of the coastal planktonic ecosystem to idealized synoptic (∼10 days) wind intensification and relaxation of the same amplitude. We find that these perturbations induce spatio-temporal oscillations of plankton concentrations. Zooplankton response occurred with a time lag that manifests itself in space as an equatorward/downstream shift in distribution relative to phytoplankton. Overall, the transmission of the synoptic perturbation from the physics to zooplankton is characterized by a damping in relative anomalies. All these elements and the weakness of the asymmetries in the biogeochemical/planktonic ecosystem responses between intensification and relaxation events support the hypothesis that synoptic variability has limited impact on the climatological state of low–latitude upwelling systems such as the SSUS. PLAIN LANGUAGE SUMMARY In some coastal regions of the world such as off Senegal, winds preferentially blow alongshore and induce subsurface, cold and nutrient rich waters to rise to the surface layer and favor the development of plankton blooms. These so-called upwelling favorable winds are not steady. Their fluctuations produce dynamical and biogeochemical variability over a broad range of scales. Here, we studied the biogeochemical effect of 10-day (i.e. weather or synoptic) wind fluctuations over the southern Senegal continental shelf. We used a numerical model with a simplified planktonic ecosystem consisting of two phytoplankton and two zooplankton size classes. The wind perturbations modulate ocean physics, the enrichment of the sun-lit surface layer in nutrients and the planktonic ecosystem. The plankton’s response to wind fluctuations exhibited oscillations more complex and relatively less intense than those of the wind. The modest effect of the studied short-term wind fluctuations on plankton found in this study may be specific to low-latitude coastal oceans with wide continental shelves.

AIGD-PFT: the first AI-driven global daily gap-free 4 km phytoplankton functional type data product from 1998 to 2023

Abstract. Long time series of spatiotemporally continuous phytoplankton functional type (PFT) data are essential for understanding marine ecosystems and global biogeochemical cycles as well as for effective marine management. In this study, we integrated artificial intelligence (AI) technology with multisource marine big data to develop a spatial–temporal–ecological ensemble model based on deep learning (STEE-DL). This model generated the first AI-driven global daily gap-free 4 km PFT chlorophyll a concentration product from 1998 to 2023 (AIGD-PFT). The AIGD-PFT significantly enhances the accuracy and spatiotemporal coverage of quantifying eight major PFTs: diatoms, dinoflagellates, haptophytes, pelagophytes, cryptophytes, green algae, prokaryotes, and Prochlorococcus. The model input encompasses (1) physical oceanographic, biogeochemical, and spatiotemporal information and (2) ocean colour data (OC-CCI v6.0) that have been gap-filled using a discrete cosine transform–penalized least squares (DCT-PLS) approach. The STEE-DL model utilizes an ensemble strategy with 100 residual neural network (ResNet) models, applying Monte Carlo and bootstrapping methods to estimate the optimal PFT chlorophyll a concentration and assess the model uncertainty through ensemble means and standard deviations. The model's performance was validated using multiple cross-validation strategies – random, spatial-block, and temporal-block methods – combined with in situ data, demonstrating STEE-DL's robustness and generalization capability. The daily updates and seamless nature of the AIGD-PFT data product capture the complex dynamics of coastal regions effectively. Finally, through a comparative analysis using a triple-collocation analysis (TCA) approach, the competitive advantages of the AIGD-PFT data product over existing products were validated. The complete product dataset (1998–2023) can be freely downloaded from https://doi.org/10.11888/RemoteSen.tpdc.301164 (Zhang and Shen, 2024a).

Biotic and abiotic properties mediating sediment microbial diversity and function in a river–lake continuum

A river–lake system plays an important role in water management by providing long-term and frequent water diversions. However, hydrological connectivity in the system can have a profound effect on sediment microbial communities through pH, nutrient concentrations, and benthos invertebrates. Consequently, identifying the key environmental factors and their driving mechanisms is vital for microbial adaptation strategies to extreme environments. In this study, we analyzed the significant difference in sediment bacterial and fungal community structures and diversity indices among Dongting Lake and its tributary rivers, which worked as a typical river-connected lake ecosystem. There were significant differences in biotic and abiotic environments in the sediment habitats of Dongting Lake and its tributary rivers. Random forest analysis revealed that pH and Mollusca were found to be the most important abiotic and biotic variables for predicting both bacterial and fungal community structures, respectively. The beta diversity decomposition analyses showed that the bacterial and fungal community compositional dissimilarities among different sections were dominated by species replacement processes, with more than half of the OTUs in each section being unique. Notably, both biotic and abiotic factors affected the number and the relative abundance of these bacterial and fungal unique OTUs, leading to changes in community composition. Mollusca, pH, TP, NO3-N, and NH4-N were negatively related to the relative abundance of Actinobacteria, Acidobacteria, Gemmatimonadetes, Planctomycetes, and Ascomycota, while Annelida and ORP were positively related to the relative abundance of Actinobacteria and Gemmatimonadetes. Additionally, PICRUSt analysis revealed that the functional dissimilarity among lakes and rivers was strengthened in unique species compared to all species in bacterial and fungal communities, and the changes of functional types helped to improve the habitat environment in the main Dongting Lake and promote the process of microbial growth. From our results, the role of macrozoobenthos and physicochemical characteristics in driving the sediment microbial community spatial variations became clear, which contributed to further understanding of the river–lake ecosystem.

Thematic Relations

This study explores the processing of noun-prep-noun combinations in prepositional phrases in Brazilian Portuguese, focusing on the syntactic-semantic relationship marked by prepositions, implies the semantic sense in which the noun is being modified. We chose to contrast particularly two types of thematic relationships like 'made of' and 'made for’, categorized as: material and function (e.g. ‘toalha de crochê’, crocheted cloth vs. agulha de crochê, crochet needle). To do so, we conducted two psycholinguistic experiments: Experiment 1 consisted of a self-paced reading/picture matching task to investigate the impact of semantic relationship on processing time; and Experiment 2 employed a cloze task (e.g. ‘toalha de ______’) and Likert scale likelihood judgments to norm the stimuli and assess cognitive preferences for the types of relation explored (i.e., material or function). Our results revealed slower reading times for the function type relation, suggesting a higher processing demand, possibly due to covert semantic computations required for this relation. Cloze completions and likelihood ratings also indicated a cognitive preference for this type of relationship. We attribute these observed patterns to the robust syntactic-semantic relationship inherent to functional type relations, coupled with a broader range of potential response options. In contrast, material type relations demonstrated a higher level of convergence among participants for cloze responses, likely due to more restricted response options and, consequently, increased probability. Future EEG studies are proposed to identify specific moments in the cognitive processing of the constituents of these structures and assess possible anticipatory effects of prepositional phrase modifiers. These discoveries make a meaningful contribution to the broader literature on language processing, aligning with analogous patterns observed in different languages with a cognitive distinction between thematic relations and feature-based (i.e., telic and constitutive relations), such as in Wisniewsky & Love, 1998; Estes et al., 2003, 2011; Pustejovsky et al., 2016; Flick et al., 2021.

Charge Mediated Changes to the Intrinsic Viscosity of Biopolymer Systems

A theoretical approach is presented to quantify the effect of ionic strength on the swelling and shrinkage of the hydrodynamic coil size of a generic biopolymer. This was conducted in view of extraction methods that often utilize acids and alkali combinations and, therefore, invariably impact the levels of salt found in commercially available biopolymers. This approach is supplemented by intrinsic viscosity measurements for the purpose of validation across a variety of biopolymer architectures, type of functionalization, as well as the quoted molar mass. By accurately capturing the magnitude of change in the coil size, it is discussed how a biopolymer coil size is far more sensitive to changes in the ionic strength than it is to the molar mass (or contour length) itself. In turn, it is highlighted why the current characterization strategies that make use of weight-averaged molar mass are prone to errors and cannot be used to establish structure—property relationships for biopolymers. As an alternative, the scope of developing an accurate understanding of coil sizes due to changes in the “soft” interactions is proposed, and it is recommended to use the coil size itself to highlight the underlying structure—property relationships.

Differences in Urban Vibrancy Enhancement among Different Mixed Land Use Types: Evidence from Shenzhen, China

Mixed land use has the advantages of promoting the economic and intensive utilization of land and improving the efficiency of land use, which can help alleviate the current urban problems and promote the sustainable development of cities. Existing studies have usually used quantitative indicators to reflect complex and diverse mixed land use situations, and the conclusions obtained usually cannot provide a basis for functional selection in mixed land use practices. Therefore, this study took Shenzhen as the study area to explore whether there are differences in the urban vibrancy enhancement among different mixed land use types. First, the block-scale mixed land use dataset of the study area was constructed. Second, the spatial distribution characteristics of the main functional types and urban vibrancy in the study area were explored. Finally, the impact of mixed land use types on urban vibrancy was explored by using a multiple linear regression model and setting land use type as the dummy variable. The results show that the number of mixed-function blocks in Shenzhen is relatively small, and the mixed land use degree still needs to be improved. Among the 12 main land use types in the study area, those containing industrial land are usually clustered in the northern industrial area of Shenzhen, those containing public or commercial service land are usually clustered in the city center, and those containing residential land are widely distributed in the study area. From the perspective of urban vibrancy, there is a phenomenon of “jobs–housing mismatch” in Shenzhen, as well as a problem of low urban vibrancy in the peripheral areas of the city. In addition, the urban vibrancy intensity of mixed land use types including residential or commercial land is higher, such as “administration+residential”, “residential+commercial”, “industrial+residential+commercial”, and “administration+residential+commercial” land, which includes residential or commercial land, is stronger, while. However, the urban vibrancy stability of mixed land use types including industrial land is higher, such as “industrial+residential” and “industrial+administration” land. The results of this study can provide a basis for future mixed land use practices in terms of land use type selection. For the urban central areas and subcenters in urban peripheral areas, mixed land use types such as “administration+residential”, “residential+commercial”, and “administration+residential+commercial” can be selected to enhance the urban vibrancy stability of the area. For industrial parks in urban peripheral areas, mixed land use types such as “industrial+residential”, “industrial+commercial”, “industrial+administration+residential”, and “administration+residential+commercial” can be selected to enhance the urban vibrancy intensity of the area.

Semantic-Type-Guided Bug Finding

In recent years, there has been an increased interest in tools that establish incorrectness rather than correctness of program properties. In this work we build on this approach by developing a novel methodology to prove incorrectness of semantic typing properties of functional programs, extending the incorrectness approach to the model theory of functional program typing. We define a semantic type refuter which refutes semantic typings for a simple functional language. We prove our refuter is co-recursively enumerable, and that it is sound and complete with respect to a semantic typing notion. An initial implementation is described which uses symbolic evaluation to efficiently find type errors over a functional language with a rich type system.

The pace of life for forest trees.

Tree growth and longevity trade-offs fundamentally shape the terrestrial carbon balance. Yet, we lack a unified understanding of how such trade-offs vary across the world's forests. By mapping life history traits for a wide range of species across the Americas, we reveal considerable variation in life expectancies from 10 centimeters in diameter (ranging from 1.3 to 3195 years) and show that the pace of life for trees can be accurately classified into four demographic functional types. We found emergent patterns in the strength of trade-offs between growth and longevity across a temperature gradient. Furthermore, we show that the diversity of life history traits varies predictably across forest biomes, giving rise to a positive relationship between trait diversity and productivity. Our pan-latitudinal assessment provides new insights into the demographic mechanisms that govern the carbon turnover rate across forest biomes.

Emerging landscapes of “alternative-academic” careers in library and information science: Evolutionary patterns and prospects in the Chinese context

This study investigated the emerging landscape of alternative-academic careers in the field of library and information science in China using text mining techniques on a dataset of 7832 job postings from 334 institutions between 2016 and 2023. The findings revealed that alternative-academic positions are widely distributed across academic, cultural, governmental, and commercial institutions, with a growing presence in interdisciplinary and applied research domains. The results highlight the emergence of four distinct functional types: resource construction, academic services, intelligence research, and social functions. Alternative-academic roles have evolved towards greater professionalization, specialization, and collaboration, reflecting the shifting demands of the digital information landscape.

Soil moisture and water redistribution patterns in white oak (Quercus alba) saplings and trees in fragmented urban woodlands

In the midwestern United States, models predict extended summer heatwaves and increasingly frequent and prolonged drought conditions. In the Chicago region, the potential for large-scale mortality of white oak trees (Quercus alba) coupled with the ongoing decline of white oak sapling recruitment are major concerns for researchers and practitioners. In this study, we determined the sources of water used by mature white oak trees and saplings in three qualitatively different sites within a remnant oak forest in Chicago during the 2021 drought. We investigated soil moisture dynamics (volumetric water content, VWC) and water isotope composition of leaf tissues (δD, δ18O), rainwater, and groundwater. These data were linked to sapling height (proxy for biomass) and ectomycorrhizal (ECM) functional types. We predicted that: (i) mature oak trees use deeper water sources and conducted hydraulic redistribution (HR), and (ii) mature trees shared water with saplings during dry periods via long-distance ECM functional types. Soil moisture decreased progressively from June to October (spring to fall), with August and September having the lowest moisture (<20 % VWC). Following rainfall recharge, temporal patterns of soil moisture showed gravity drainage and then ongoing stair-stepwise drawdown consistent with plant evapotranspiration. Leaf δD and δ18O values in mature trees and saplings were consistent with water uptake from rainfall and subsequent enrichment via evapotranspiration. In two sites, mature trees and saplings demonstrated distinct δD: δ18O slopes, with mature trees more enriched than saplings. In the third site, mature trees and saplings δD: δ18O slopes overlapped but here, the ECM community was dominated by contact-type ECM and sapling height increased with distance from the mature oak. Our findings indicate that HR was not a component of site ecohydrology, and future climate conditions may present increasing challenges for white oak recruitment as both mature trees and saplings compete for limited rainfall-derived soil moisture.

Plant functional type and peat properties determine elemental transfer in boreal mire vegetation

Uptake of elements into plants is an integral part of many environmental impact assessments. Typically, the plant uptake is determined using an empirical soil-to-plant transfer factor (CR). The elemental concentrations in plants are expected to vary with plant species and plant functional type (PFT), but also according to soil and element properties. Specifically, the uptake of essential elements is regulated, and likely less related to soil concentrations than the uptake of non-essential elements. In this study, the impact of PFT, species and environmental factors on the CR of mire plants was tested. The plants included in the study were four common boreal peatland species (Andromeda polifolia, Vaccinium oxycoccus, Eriophorum vaginatum and Carex rostrata) sampled from 40 minerogenic mires along an age gradient.The results show that while plant species and PFT (heathers and sedges) are the main determinants of the CR value, also environmental factors, such as peat C:N ratio, are important. Further, concentrations of essential elements in plants were only weakly correlated to peat concentrations, whereas the correlation was stronger for non-essential elements and elements utilized at trace amounts.The results of this study verify that CR values may vary substantially between peatland plant species and PFTs. Further, the results suggest that it is relevant to include effects of PFTs on CR and among-species variation in environmental impact assessments. This is because the PFT may have a large impact on the exposure pathways to humans, which could, for example, be berries or animal feed, and also due to the uncertainties of the composition of the future vegetation communities. Since CR varies systematically with several soil properties, there may be potential for adjusting the CR values for expected environmental changes, and thereby reduce the uncertainties of empirical CR values determined from a broad range of environmental conditions.

Evaluation of Leaf Phenology of Different Vegetation Types From Local to Hemispheric Scale in CLM

AbstractAccurate simulation of plant phenology is important in Earth system models as phenology modulates land‐atmosphere coupling and the carbon cycle. Evaluations based on grid cell average leaf area index (LAI) can be misleading because multiple plant functional types (PFTs) may be present in one model grid cell and PFTs with different phenology schemes have different LAI seasonal cycles. Here we examined PFT‐specific LAI magnitudes and seasonal cycles in the Community Land Model versions 5.0 and 4.5 (CLM5.0 and CLM4.5) and their relationship with the onset of growing season triggers in the Northern Hemisphere. LAI seasonal cycle and spring onset in CLM show the best agreement with Moderate Resolution Imaging Spectroradiometer (MODIS) for temperature‐dominated deciduous PFTs. Although the agreement in LAI magnitude between CLM5.0 and MODIS is better than CLM4.5, the agreement in seasonal cycles is worse in CLM5.0. Agreements between CLM and MODIS leaf phenology are primarily determined by the PFT and phenology scheme. While productivity depends on the environmental factors to which the plant is exposed during any given growing season, differences in phenology sensitivity to its environment necessitate a decoupling between the seasonality of LAI and GPP, which in turn could lead to biases in the carbon cycle as well as surface energy balance and hence land‐atmosphere interactions. Because the discrepancy not only depends on parameterizing phenology but phenology‐environment relationship, future improvements to other model components (e.g., soil moisture) could better align the seasonal cycle of LAI and GPP.

Forest structure explains spatial heterogeneity of decadal carbon dynamics in a cool-temperate forest

Abstract Accurate evaluation of forest biomass distribution and its long-term change over wide areas is required for effective forest carbon management and prediction of landscape-scale forest dynamics. We evaluated a landscape-scale (225 km2) decadal forest carbon budget at a 1 ha spatial resolution in a cool-temperate forest, by repeating airborne laser observations 10 years apart and partitioning net forest biomass change (FBC) into growth and mortality. Using &gt;10 000 samples, we revealed that naturally regenerated forests have large spatial heterogeneity in net biomass change, and 3/4 of the photosynthetically acquired carbon stock moved to necromass even without anthropogenic disturbances. Actual carbon residence time as living tree biomass was estimated by dividing biomass by growth or mortality rates. The residence time was 107 and 106 years, respectively with large spatial variation among stands (48 and 42 years, respectively, as the difference between 25 and 75 percentile), although studied forest stands have small variation in the forest functional type in a landscape-scale. The best predictors of subsequent decadal biomass changes were two forest structural factors, mean canopy height and canopy height variation in addition to one environmental factor, elevation. Considering the long lifetime of trees, these structural factors may be an indicator of forest soundness rather than a cause of forest growth or mortality. However, in any cases, these structural factors can be powerful predictors of subsequent FBC.

Nitrogen addition and plant functional type mediate the mesofauna-driven litter element release of subtropical forest

Nitrogen addition and plant functional type mediate the mesofauna-driven litter element release of subtropical forest

Forbs from seasonal managed wetlands boost plankton production more than emergent graminoids by supplying novel labile detritus

Abstract Opportunities to enhance ecosystem functions exist in human‐dominated working landscapes, but understanding of key drivers is often lacking in these novel environments. In Suisun Marsh, California, USA, impounded managed wetlands designed to promote waterfowl incidentally support higher plankton densities—a key resource for imperilled pelagic fishes—than adjacent tidal habitats. Managed wetland operations could produce plankton at critical periods for fish and the aquatic food‐web more broadly, but drivers of plankton production in managed wetlands are poorly understood. We proposed that decaying vegetation resulting from controlled flooding in managed wetlands is important for stimulating plankton blooms, but that the effect varies by plant species and functional type. We conducted a mesocosm experiment to test the effects of different inundated plants on plankton production, including three forb species, three emergent graminoid species and a control treatment without added plant material. Forbs promoted larger phytoplankton blooms and higher zooplankton production—by an order of magnitude—than both emergent graminoids and the control treatment. Emergent graminoids supported larger phytoplankton blooms, but not higher zooplankton production, than the control treatment. Phytoplankton blooms exhibited pulse dynamics in all treatments, with densities increasing initially and crashing by the end of the experiment. Phytoplankton blooms in forb and emergent treatments lasted similar durations, counter to the expectation that emergent graminoids would support diminished production over a relatively prolonged period. Among zooplankton taxa, Daphnia magna and rotifers were strongly associated with all three forbs species while the nonnative cyclopoid copepod Limnothoina tetraspina were associated with cattails (Typha domingensis) and the control. Forbs temporarily depleted dissolved oxygen concentrations during the first week of the experiment, suggesting a tradeoff by which decaying forbs boost plankton production at risk of initial hypoxia. Our results suggest that seasonal drying and flooding operations in managed wetlands are likely to enhance plankton production because dry periods promote forb growth and subsequent flooding introduces labile forb material to the aquatic food web. Results also suggest that seasonal managed‐wetlands act as novel floodplain‐analogues, by which flood pulses drive productivity. Further research is needed to quantify production benefits and tradeoffs to the aquatic ecosystem at the landscape scale and to identify optimal management regimes that will help conserve imperilled species.

THE CURRENT STATE OF AGRICULTURAL LAND USE IN THE CONTEXT OF SUSTAINABLE DEVELOPMENT

This article discusses the rational use of agricultural land, taking into account structural and resource indicators for sustainable development. The effectiveness of land use in farms with different forms of land ownership depends on increasing labor productivity, strengthening the economy regime, increasing the intensification of production, using internal reserves and opportunities for agricultural production and, especially, rational use of land. The basis for the formation of sustainable land use should be strict observance of the established relationships between disturbed and undisturbed territories. Undisturbed territories should be considered as a stabilizing factor neutralizing anthropogenic impacts on the landscape. In this regard, the tasks of preserving productive agricultural land, optimizing arable land and acreage in terms of quantitative and qualitative characteristics of land are becoming a priority. The solution of these tasks is connected with the improvement of technologies for maintaining and increasing the bioproductivity of agricultural lands, the development of technologies for rational land management, land use and land protection, the creation of effective organizational and legal mechanisms for managing agricultural lands, as well as the development of state monitoring of agricultural lands. In order to approach the practice of determining the efficiency of land use, it is necessary to focus in more detail on its factors according to the selected functional subsystems and types of efficiency.

Lexical Bundle Patterns in Malaysian Educational Texts: A Corpus-Based Analysis of English Language Textbooks

In the era of digital learning, understanding the linguistic input in educational materials is vital for language acquisition. Lexical bundles, or recurring word sequences, significantly contribute to developing fluency and coherence, especially in academic contexts. This study examines the presence and types of lexical bundles in Malaysian Form 4 and Form 5 KBSM English textbooks, analyzing their frequency and functions. Using a mixed-method design with a corpus-based approach, data were collected from textbook reading passages and analyzed with AntConc 3.4.3 software. The study aims to assess whether these textbooks provide sufficient linguistic input to enhance students' English proficiency in academic contexts. The findings show a limited presence of lexical bundles, with 29 different 3-word bundles appearing 203 times in total. Four-word bundles were not found in the corpus. The bundles were categorized into three functional types based on Biber et al.'s (2004) taxonomy; stance expressions (55.2%), referential expressions (44.8%), and discourse organizers which were absent. This gap suggests a shortfall in the textbooks' ability to guide students in creating coherent and well-structured texts. The study emphasizes the need for more comprehensive inclusion of lexical bundles in textbooks to better support language acquisition and academic proficiency. It recommends that future textbooks incorporate a broader range of lexical bundles to better equip students for advanced language uses. This research contributes to discussions on the effectiveness of educational materials in second language learning and highlights the importance of targeted linguistic input.

Neighborhood structure, more than soil nutrients, influences net tree interactions among different functional types in a temperate forest

Tree-tree interactions are fundamental in shaping forest community dynamics, driven by factors such as nutrient availability and species composition. While recent research underscores the role of functional traits in influencing tree sensitivity to neighborhood interactions, a clear consensus is lacking on how these traits interact with biotic and abiotic factors. Based on a multi-level modeling approach, this study examines how specific leaf area (SLA), potential maximum tree height (Hmax), and wood density (WD) mediate the combined effects of soil nutrients and neighborhood biotic factors on net tree interactions among 4,210 individual stems for 13 species in a 30-ha temperate forest in northeastern China. The findings indicate that while functional traits independently account for a small portion of the variation in net tree interaction intensity (NIntC), they significantly mediate the effects of neighborhood crowding, neighborhood structure, and soil nutrients on NIntC. Specifically, only the response of growth NIntC of species with low-Hmax to available phosphorus (AP) was consistent with the stress gradient hypothesis. Conspecific neighborhood crowding consistently increases competitive NIntC, whereas heterospecific neighborhood crowding significantly facilitates survival NIntC. Moreover, the positive impact of heterospecific crowding on survival NIntC is significantly greater for high-Hmax species compared to low-Hmax species. Neighborhoods with higher tree species diversity, greater size heterogeneity, and more uniform distribution increase the facilitative NIntC of high-SLA or high-WD species but intensify the competitive NIntC of low-SLA or low-WD species. Our results also indicate that the relative importance of neighborhood structure exceeds that of soil nutrients in explaining variation in NIntC. When environmental conditions are difficult to change, adjusting the forest stand structure may be a more efficient way to regulate the intensity of interactions between trees and improve forest productivity.