Distinct Vegetation Types Research Articles

Structure and function role of soil nematode communities in different types of vegetation in Yogyakarta and Central Java, Indonesia

Abstract. Indarti S, Utami SNH, Putra NS, Maharani R. 2024. Structure and function role of soil nematode communities in different types of vegetation in Yogyakarta and Central Java, Indonesia. Biodiversitas 25: 2765-2772. Soil nematodes are crucial parts of the soil organism community and play a significant role in many ecological soil processes. It is necessary to pay greater attention to the lack of knowledge regarding the composition and role of the soil nematode community in different vegetations. Hence, the nematode structure community from minimal to soil stillages have been observed and compared from seven distinct types of vegetation. This study aimed to determine the soil nematode community structure, which includes the dominance, abundance, richness, diversity, and functional role of nematodes, as well as other chemical soil properties. Vegetation type represents soil management and has an impact on the life of soil organisms such as nematodes. A total of approximately 2328 soil nematodes were found, and 18 genera were identified. The Nematode Indicator Joint Analysis (NINJA) revealed that the vegetation type, land use, and soil chemical properties influence the nematode’s abundance, dominance, and structure differently. Through those results, the authors confirmed that soil nematodes in cultivated vegetation are dominated by the trophic groups of plant-parasitic nematodes and bacterivores. Conversely, predator, omnivores, and fungivores nematodes dominate in soil with minimal tillage. Overall, this study highlights the importance of soil nematode analysis in sustainable agricultural soil ecosystems.

Functional trait patterns: investigating variation-covariation relationships and the importance of intraspecific variability along distinct vegetation types

Functional trait patterns: investigating variation-covariation relationships and the importance of intraspecific variability along distinct vegetation types

VELVET: an enclosure vegetation system to measure BVOC emission fingerprints in temperate and tropical climates

The VELVET chamber, utilizing the vegetation enclosure technique, was used to measure biogenic volatile organic compound (BVOC) emissions from representative plant leaves in temperate and tropical climates. This study demonstrates the instrument’s capability, among the various measurements conducted in other studies using the vegetation enclosure technique, in qualifying and quantifying volatile organic compound (VOC) emissions from different tree species. The measurements were performed using Tenax tubes for sampling and GC/MS analysis. The use of PTR-ToF-MS for temperate species allows us to perform flux measurements in the chamber of Norway spruce (Picea abies), European beech (Fagus sylvatica), and common hazel tree (Corylus avellana) in the Puy de Dôme region (France). We found that all species are monoterpene emitters (on average 1.52 ± 0.29 ng m−2 s−1) and more particularly sesquiterpene emitters for C. avellana (7.49 ± 0.70 ng m−2 s−1). In the tropical region of Réunion Island (France), comprehensive measurements were conducted across three distinct vegetation types, on 10 of the most representative species, native and exotic to the island. The study revealed that emissions from these species were influenced by spatial variability, their environment, and the type of the forest (cloud forest, and high- and low-altitude forests). Notably, the research marked a groundbreaking achievement by capturing emissions from endemic species on the island for the first time. The collected data will be added to the biogenic emission inventory of the island, thereby enhancing model simulations by incorporating these new measurements.

Unraveling the biodiversity in the Brazilian wetlands: dung beetle assemblage in different vegetation types in the Araguaia Pantanal

ABSTRACT The Araguaia Pantanal is characterized by a mosaic of vegetation with high biodiversity. However, our understanding of this biodiversity remains limited and understudied. Therefore, the objective of this study was to evaluate the distribution patterns of dung beetles in different vegetation types (Deciduous Forest, Savanna, Riparian Forest, Murundu Fields, and Exotic Pastures). In addition, we analyzed how forest cover influence the species richness, abundance, and species composition of dung beetles. A total of 12,746 dung beetles representing 67 different species were captured and examined. Our findings revealed that the Murundu Fields exhibited lower species richness and abundance of dung beetles, indicating the influence of distinct vegetation types directly associated with flood pulses in the region. Furthermore, the species composition of the Murundu Fields was found to be a subset of the adjacent vegetation, primarily composed of Savanna and Deciduous Forest species. Additionally, our results demonstrated that tree cover played a significant role in driving dung beetle species turnover among the studied sites, highlighting the species’ response to the existing gradient of vegetational changes within the region. We believe that our study contributes valuable insights into the distribution and ecological dynamics of dung beetles in the Araguaia Pantanal.

Fungal, but not bacterial, diversity and network complexity promote network stability during roadside slope restoration

To restore degraded roadside ecosystems, conventional methods such as revegetation and soil amendment are frequently employed. However, our understanding of the long-term effects of these restoration approaches on soil microbial diversity and network complexity across different vegetation types remains poor, which contributes to poor restoration outcomes. In this study, we explored the effects of roadside slope restoration on microbial communities across different vegetation types at varying stages of restoration. We found that restoration time had a more pronounced impact on microbial diversity than specific vegetation type. As restoration progressed, microbial network complexity and fungal diversity increased, but bacterial diversity declined, suggesting that keystone taxa may contribute to network complexity. Interestingly, bacterial network complexity increased concomitant with decreasing network modularity and robustness, which may compromise system stability. Distinct vegetation types were associated with restoration-sensitive microbial communities at different restoration stages. Leguminouse and nitrogen-fixing plants, such as Albiziak alkora, Ginkgo biloba, Rhus chinensis, Rhapis excels, and Rubia cordifolia exhibited such associations after five years of restoration. These keystone taxa included Proteobacteria, Actinobacteria, Chloroflexi, Gemmatimonadota, and Myxococcota. We also found that bacterial alpha diversity was significantly correlated with restoration time, soil pH, moisture, available phosphate, nitrate nitrogen, and plant height, while fungal diversity was primarily shaped by restoration time. Together, our findings suggest that soil properties, environmental factors, vegetation type, and dominant species can be manipulated to guide the trajectory of ecological recovery by regulating the abundance of certain microbial taxa.

Rainfall-runoff partitioning in small watersheds of different vegetation types in the loess area based on hydrogen and oxygen isotope tracing.

Recognizing watershed runoff process and its component sources is a prerequisite for the rational use of water resources. To elucidate the effects and quantitative contributions of various vegetation types on the components of watershed runoff, we centered on the Caijiachuan main channel watershed in Jixian, Shanxi and five sub-watersheds with distinct vegetation types. By tracking the hydrological responses to two representative rainfall events and assessing the spatiotemporal variations in hydrogen and oxygen isotope signatures, we aimed to discern disparities in the runoff processes across these sub-watersheds and pinpoint their constituent origins. The results showed that under medium rainfall condition, the contribution rates of event water to the river flow of each watershed were in an order of protected forest (94.3%) > Caijiachuan main channel (83.1%) > agro-pastoral composite (64.3%) > plantation-secondary forest (52.4%) > cropland (0.3%) > secondary forest (0.0%); under light rainfall condition, plantation-secondary forest (52.4%) > protected forest (58.5%) > cropland (40.6%) > secondary forest (15.8%) > agro-pastoral composite (12.5%) > Caijiachuan main channel (9.3%). The event water contribution rate of secondary forest and protected forest watersheds to runoff was higher than that of plantation watersheds. The secondary forests watersheds had a stronger runoff storage capacity. The event water contribution rate of protected forest and agro-pastoral composite watersheds under medium rainfall intensity condition was greater than that under light rainfall intensity condition, while the event water contribution rate of cropland, plantation-secondary forest, and secondary forest watersheds was in adverse. The event water contribution to the runoff of forested watersheds was greater than that of cropland watersheds, which may be related to the presence of silt dams at the mouth of agricultural watershed channels. This study can provide a scientific basis for the analysis of water conservation and runoff change attribution in the loess area of west Shanxi.

Dynamic Shifts in Soil Fungal Functional Group Characteristics across Distinct Vegetation Types during Ecological Restoration in Degraded Red Soil Regions

The red soil region in southern China has become the second-largest soil erosion area after the Loess Plateau. The evolutionary trajectory of soil fungi during vegetation restoration in acidic red soil regions remains a subject of inquiry. The investigation focused on the restoration process of an ecosystem facing intense degradation in the southern regions of China by studying four distinctive vegetation types: barren land (BL), pure Pinus massoniana forest (CF), mixed coniferous (CBF), and broad-leaved forest (BF). The outcomes revealed considerable enhancements in soil properties’ attributes, evident through a gradual reduction in the bulk density of soil (SBD) and a corresponding increment in soil moisture content (MC), total nitrogen (TN), total carbon (TC), total potassium (TK), soil organic matter (SOM), and available potassium (AK) as vegetation restoration advanced. An intriguing trend emerged where the relative abundance of Ascomycota fungi displayed a declining trajectory, whereas Basidiomycota fungi exhibited an ascending trend with the progression of vegetation restoration. Specifically, broad-leaved forests exhibited a significantly greater relative abundance of Penicillium fungi compared to other stages of vegetation restoration. The diversity of soil fungal communities increased in tandem with vegetation restoration. A redundancy analysis illuminated a strong and positive relationship between the abundance of major soil fungi and soil pH, TN, and TC (key influencers of acidic red soil fungal populations). This study provided additional evidence of an elevation in ectomycorrhizal and saprophytic trophic fungi, signifying a transition that enhances the vegetation’s ability to capture water and nutrients. This, in turn, contributes to the overall enrichment and diversity of vegetation communities during the progression of restoration.

Similarities and differences in the microbial structure of surface soils of different vegetation types.

Soil microbial community diversity serves as a highly sensitive indicator for assessing the response of terrestrial ecosystems to various changes, and it holds significant ecological relevance in terms of indicating ecological alterations. At the global scale, vegetation type acts as a major driving force behind the diversity of soil microbial communities, encompassing both bacterial and fungal components. Modifications in vegetation type not only induce transformations in the visual appearance of land, but also influence the soil ecosystem's material cycle and energy flow, resulting in substantial impacts on the composition and performance of soil microbes. In order to examine the disparities in the structure and diversity of soil microbial communities across distinct vegetation types, we opted to utilize sample plots representing four specific vegetation types. These included a woodland with the dominant tree species Drypetes perreticulata, a woodland with the dominant tree species Horsfieldia hainanensis, a Zea mays farmland and a Citrus reticulata fields. Through the application of high-throughput sequencing, the 16S V3_V4 region of soil bacteria and the ITS region of fungi were sequenced in this experiment. Subsequently, a comparative analysis was conducted to explore and assess the structure and dissimilarities of soil bacterial and fungal communities of the four vegetation types were analyzed comparatively. Our findings indicated that woodland soil exhibit a higher richness of microbial diversity compared to farmland soils. There were significant differences between woodland and farmland soil microbial community composition. However, all four dominant phyla of soil fungi were Ascomycota across the four vegetation types, but the bacterial dominant phyla were different in the two-farmland soil microbial communities with the highest similarity. Furthermore, we established a significant correlation between the nutrient content of different vegetation types and the relative abundance of soil microorganisms at both phyla and genus levels. This experiment serves as a crucial step towards unraveling the intricate relationships between plants, soil microbes, and soil, as well as understanding the underlying driving mechanism.

Conservation of tree phylogenetic diversity in the Brazilian Atlantic Forest: Dry habitats matter

Conservation assessments that aim to represent the pool of lineages that exist within a region are challenging due to incomplete knowledge of the spatial distribution and environmental preferences of distinct lineages. In this context, community-level models represent a powerful tool that can be used to predict spatial variation in phylogenetic composition. If lineages composition and habitat loss present a non-random spatial pattern within a region, we can expect that some lineages are more threatened by habitat loss than others. To test this hypothesis we combined multivariate analysis and a modelling approach to predict the phylogenetic composition of angiosperm tree/shrub communities in Rio de Janeiro State, southeastern Brazil, which is regarded as a plant endemism center within the Brazilian Atlantic forest biome. Then we correlated the resulting models with maps of vegetation cover and protected areas, to identify lineages subjected to higher habitat loss and clades that receive less protection. We found that angiosperm tree/shrub lineages are highly structured across distinct vegetation types and that a gradient of deforestation and land protection parallels the phylogenetic gradient formed by the distinct vegetation types. Consequently, some vegetation types and its associated angiosperm lineages are much more threatened by habitat loss and are less protected than others. Specifically, Ericales (asterids), Caryophyllales and Santalales are the most threatened clades in this region, along with their preferred habitats, seasonal forests and coastal white-sand forests (restingas). Protecting and restoring these dry habitats is critical for the conservation of tree and shrub phylogenetic diversity in the Brazilian Atlantic forest.

Do grazers equal grasslands? Strengthening paleoenvironmental inferences through analysis of present-day African mammals

Expanding grassy ecosystems through the late Cenozoic may have driven ecological and evolutionary change in hominins and other African mammals. However, we lack a sufficiently robust quantitative framework to understand how species should respond to changing vegetation structure or the magnitude of change needed to drive range shifts, speciation, extinction, or adaptation. A more detailed understanding of present-day species-environment relationships at scales appropriate to paleoenvironmental records can help build this framework. Here, we use generalized additive models to estimate modern-day herbivore responses to woody cover gradients across 100+ present-day African parks and reserves. We examine these responses for 58 herbivore species (Artiodactyla, Perissodactyla, Proboscidea) and with species aggregated by tribe (for Bovidae) and dietary functional group (browser, grazer, mixed feeder, frugivore). At the spatial scales of our analysis (i.e., parks and reserves measuring ∼500–5000 km2), we find that few species have strong associations with open (<0.3 fraction woody cover) or closed (>0.7 fraction woody cover) environments. Most herbivores demonstrate a peak probability of presence around 0.5 fraction woody cover. The latter result is consistent with the ecological conditions previously shown to maximize herbivore diversity. At landscape-to-ecosystem spatial scales (102–103 km2), which average across finer-scale patches of distinct vegetation types (e.g., grassland, woodland, forest), our results indicate that a taxonomically and ecologically diverse group of species are expected to co-occur. We argue that spatiotemporal scale likely accounts for the ubiquity of mosaic habitat reconstructions in time-averaged fossil assemblages from the late Cenozoic of Africa. In addition, we propose that species' broad tolerances for gradients in woody cover renders the expansion of C4-dominated ecosystems an uncertain driver of macroevolutionary change (i.e., speciation and extinction) in Africa through the Plio-Pleistocene.

Unveiling Temperature Patterns in Tree Canopies across Diverse Heights and Types

Forests are some of the major ecosystems that help in mitigating the effects of climate change. Understanding the relation between the surface temperatures of different vegetation and trees and their heights is very crucial in understanding events such as wildfires. In this work, relationships between tree canopy temperature and canopy height with respect to vegetation types were extracted. The southern part of Sardinia Island, which has dense forests and is often affected by wildfires, was selected as the region of interest. PRISMA hyperspectral imagery has been used to map all the available vegetation types in the region of interest using the support vector machine classifier with an accuracy of &gt;80% for all classes. The Global Ecosystem Dynamics Investigation’s (GEDI) L2A Raster Canopy Top Height product provides canopy height measurements in spatially discrete footprints, and to overcome this issue of discontinuous sampling, Random Forest Regression was used on Sentinel-1 SAR data, Sentinel-2 multispectral data, and the Shuttle Radar Topography Mission (SRTM) digital elevation model (DEM) to estimate the canopy heights of various vegetation classes, with a root mean squared error (RMSE) value of 2.9176 m and a coefficient of determination (R2) value of 0.791. Finally, the Moderate Resolution Imaging Spectroradiometer (MODIS) Land Surface Temperature (LST) and emissivity product provides ground surface temperature regardless of land use and land cover (LULC) types. LST measurements over tree canopies are considered as the tree canopy temperature. We estimated the relationship between the canopy temperature of five vegetation types (evergreen oak, olive, juniper, silicicole, riparian trees) and the corresponding canopy heights and vegetation types. The resulting scatter plots showed that lower tree canopy temperatures correspond with higher tree canopies with a correlation coefficient in the range of −0.4 to −0.5 for distinct types of vegetation.

Response of Soil Microbial Communities to Elevation Gradient in Central Subtropical Pinus taiwanensis and Pinus massoniana Forests

In forest ecosystems, elevation gradient is one of the most influential factors on soil characteristics, vegetation types, and soil microorganisms. However, it remains unclear how the elevation gradient and the soil environment under its influence affect soil microbial communities under two distinct vegetation types. In this study, high-throughput sequencing technology from Illumina was utilized to examine the response of soil microbial communities to elevation and their driving factors in forests of Pinus taiwanensis and Pinus massoniana in various Jiangxi Province locales. The results demonstrated that the elevation gradients of the two pines had significant effects on soil organic carbon (SOC) and total nitrogen (TN), both in unimodal mode as well as on the alpha diversity of soil microbes. The community structure of soil bacteria is more sensitive to elevation than that of soil fungus. At different elevations in the two pine forests, Acidobacteria, Proteobacteria, Chloroflexi, Verrucomicrobia, Bacteroidetes, Patescibacteria, and Thaumarchaeota are the dominant bacterial phyla, and Ascomycota, Basidiomycota, and Mucoromycota are the dominant fungal phyla. This investigation revealed that SOC and TN were the two most influential factors on the alteration of the soil microbial community in two pine forests. In summary, there were substantial changes in soil microbial diversity and community composition across the two different pine forests, with elevation and soil characteristics (SOC and TN) serving as the primary drivers.

Very high-resolution Net Ecosystem Exchange over India using Vegetation Photosynthesis and Respiration Model (VPRM) simulations

The terrestrial biosphere has a crucial role in controlling the rate of CO2 accumulation in the atmosphere. The quantification of Net Ecosystem Exchange (NEE) is critical to determine whether the regional terrestrial ecosystem is a net sink or source of CO2. This study uses a satellite-data derived light-use-efficiency model (the Vegetation Photosynthesis and Respiration Model, VPRM) to compute the biospheric CO2 fluxes over India from 2011–2020. A very high-resolution Land Use-Land Cover (LULC) data from the IRS-P6 satellite and MODIS derived surface reflectance are utilised to compute the NEE over distinct vegetation types at ∼9km× 9 km. The VPRM model for the Indian region captures the spatial pattern and seasonal features of NEE over the country. The magnitude of annual mean NEE over India from the VPRM model is relatively high compared to that from Carbon Tracker, FLUXCOM, and Soil Moisture Active Passive Level-4 carbon data products. However, the VPRM model simulated NEE agrees with the NEE observations from the eddy covariance estimates, which are accepted as the ground truth. The fusion of high-resolution LULC and surface reflectance data in VPRM suggests that the average NEE over the Indian region during 2011–2020 is −0.16 ± 0.02 PgC yr−1. Among this, the contribution from Gross Ecosystem Exchange is about −0.47 ± 0.02 PgC yr−1, and Respiration is 0.31 ± 0.01 PgC yr−1. The maximum biospheric CO2 absorption is during the post-monsoon season, and the minimum is during the pre-monsoon season. The very high spatial resolution and heterogeneity resolved in the NEE data derived in this work offer the first data product of this kind for a variety of NEE analyses over India.

Past climate changes and geographical barriers: the evolutionary history of a subtropical highland grassland species of Solanaceae,Petunia altiplana

AbstractClimate changes and associated glacial and interglacial cycles during the Quaternary strongly influenced the evolutionary history of countless number of species. Subtropical highland grasslands (SHG) in southern South America constitute a distinct vegetation type with high diversity and endemism rates. The most recent common ancestor of the genus Petunia (Solanaceae) originated in lowland grasslands, and some lineages secondarily migrated to SHG. Here, we describe the evolutionary history of an SHG species, P. altiplana, distributed throughout a wide area in a river-fragmented landscape. We used plastid and nuclear markers to evaluate the role of the Pelotas River and Quaternary climate cycles over the genetic structure and historical demography of this species based on a phylogeographical approach. We found moderate population expansions during the last 25 kyr, with a more recent (c. 1.6 kya) divergence between two groups of populations from opposite river margins, possibly caused by the expansion of the Araucaria Forest along the river valley, effectively isolating distinct grassland patches.

Potential role of high-altitude wetlands in preservation of plant biodiversity under changing climatic conditions in the arid Eastern Pamir

High-altitude wetlands in the Eastern Pamir are habitat islands located in an arid landscape. They play several important roles, including that of water sources and forage grounds for people and their livestock. Considering high variation in micro-relief and complexity of water supplies observed in these wetlands, we assessed their potential to play a role of refugia for species whose present ranges may be limited by climate changes projected for Central Asia. Such species currently occur typically in less moist habitats, often located at lower elevations (e.g. steppe and meadow species). To perform this assessment, we analyzed current spatial structure and species diversity of vegetation accompanying selected water bodies in the studied catchments, identified present changes in temperature and precipitation in these catchments and analyzed alterations in area of lakes and small water bodies located in the vegetation mosaic. Presently, the biodiversity of the studied wetlands comprises 110 species of vascular plants from 26 families, forming ten distinct vegetation types, over 40 recorded species are typical for steppes and various types of alpine meadows. Both meteorological data and satellite data on open water area indicated that with growing temperatures, areas of the studied lakes and small water bodies in the vegetation mosaic increase. This effect is probably caused by thawing of ground ice and permafrost, whose occurrence helps mitigate the effects of the ongoing warming and lessening precipitation. Thus, the wetlands may temporarily maintain their cold, wet and mesic characteristics under the changing climatic conditions and, as such, potentially become refugia for steppe and meadow species. However, after the period of intense thawing, lowering of groundwater level and huge surface water fluctuations may occur, potentially resulting in a decrease in the total vegetated area on lacustrine and riverine terraces in the Eastern Pamir.

Bedrock meadows: A distinct vegetation type in northwestern North America

AbstractAimsIn northwestern North America, montane meadows fed by vernal ground‐flow seepage occur scattered throughout an otherwise forested landscape on shallow soils over bedrock. Although their significance for biodiversity has been known, they have never been subject to systematic scientific research and thus, are not included in regional or national vegetation classification schemes. We provide the first vegetation survey of bedrock meadows and compare them to other major non‐forest vegetation types in the region.Study areaNorthwestern North America (United States, Canada).MethodsWe surveyed 110 plots of bedrock meadow vegetation in Montana, Idaho, and British Columbia and compared them with data from 1052 plots from six studies of other open vegetation in the region: prairie and foothill grasslands, maritime mountain, alpine, and timberline meadows. We used cluster analysis to identify groups based on vascular plant composition, related abiotic and structural characteristics to clusters using non‐metric multidimensional scaling (NMDS), and compared proportions of plant growth forms and life spans.ResultsCluster analysis identified five groups, with bedrock meadows forming a distinct community. According to the NMDS, bedrock meadows had a high cover of vascular plants, bryophytes, and lichens and a low cover of litter. Their climate was intermediate between maritime mountain and interior timberline meadows. A distinct functional feature of bedrock meadows was their high proportions of annual plants (therophytes) and plants regenerating from bulbs and corms (geophytes)—a functional composition they shared with maritime mountain meadows.ConclusionBedrock meadows have distinct floristic, functional, and environmental features, are important hotspots for biodiversity, and host several rare plant species. They are an important habitat for conservation and environmental impact assessment and should be incorporated into regional and national classification schemes. Future research priority should be given to understanding their spatial extent, ecological functioning, and drivers of non‐vascular and vascular species richness.

Phytosociological survey of juniper wood vegetation in Tajikistan (Middle Asia)

The paper presents the first syntaxonomic classification for juniper wood communities in Tajikistan with some remarks on their environmental gradients. A total of 119 relevés were sampled between 2015 and 2021 using the seven-degree Braun-Blanquet cover-abundance scale. They were classified by a modified TWINSPAN method. Diagnostic species were identified using phi coefficient as a fidelity measure. Detrended Correspondence Analysis (DCA) was used to determine relationships between samples, vegetation units and major gradients in species composition. Plant communities have been divided into two main groups. The first one is a west Irano-Turanian wood of Juniperus polycarpos var. seravschanica of the Pamir-Alai mountane belt. It occurs in two variants depending mainly on the aspect and precipitation. The second juniper wood type in Tajikistan is a stand of Juniperus pseudosabina. It prefers the northern slopes and north-eastern ranges of the Pamir-Alai and slightly lower elevations. Both juniper wood types are highly distinct in terms of species composition, especially in the moss layer, and have therefore been assigned to different classes: Pino-Juniperetea (Juniperetum seravschanicae) and Juniperetea pseudosabinae (Carici turkestanicae-Juniperetum pseudosabinae). The main factors determining the species composition of the studied associations are latitude, growing season precipitation, annual range of air temperature and precipitation of coldest quarter. Our study has shown that there are two very distinct vegetation types of the juniper wood groves in Tajikistan, which reflect the main phytogeographical division between the provinces of Turkestan and Central Asia.

Distinct leaf water potential regulation of tree species and vegetation types across the Cerrado–Amazonia transition

AbstractThe Cerrado–Amazonia transition harbors forest and savanna formations under the influence of pronounced climate seasonality; however, the water use strategies of this key region is not yet well understood. This study aimed at deciphering in intra‐ and interspecific variability in leaf water potential regulation among species across three distinct vegetation types (typical cerrado, cerradão, and semideciduous seasonal forest) of the Cerrado–Amazonia transition region. We expected a variation across iso/anisohydric strategies driven by plant–environment interactions and by species attributes (phenology and wood density). We selected 21 dominant species (seven per vegetation type), recorded their phenological strategy and wood density, and measured leaf water potential (Ψl) during the dry and rainy seasons to analyze variations associated with minimum Ψl, predawn Ψl (ΔΨpd), and midday Ψl (ΔΨmd) under the effect of variable vapor pressure deficit (VPD). The variation in Ψl across species was higher in the dry season than in the rainy season for all vegetation types. Most species from typical cerrado and cerradão showed similar behavior patterns, with higher Ψl regulation under high VPD and lower ΔΨpd. In contrast, most forest species showed lower regulation under high VPD, and higher ΔΨpd. Total or partial deciduousness together with strong stomatal regulation seems to be common water regulation strategies in the dry season for cerrado species but not for forest species. Our results suggest that, if drought events become more intense and frequent as predicted, seasonal forest species may be more vulnerable due to their lower Ψl regulation.Abstract in Portuguese is available with online material.

Diversity and regeneration strategies in woody plant communities of the Mediterranean Basin: Vegetation type matters

The Mediterranean Basin has distinct vegetation types shaped by fire, herbivory, and various human activities. Based on data from 83 belt transects of 10 × 40 m in 28 study sites for five physiognomic vegetation types (semi-closed forest, open forest, closed shrubland, open shrubland, and scrubland) in southwestern Anatolia (Turkey), we analyzed woody species diversity, woody community composition, and vegetation structure of study sites. We used the growth form and regeneration strategy for functional comparisons of physiognomic vegetation types. We found clear distinctions in diversity, species composition, and functional structure of woody plant community across five physiognomic vegetation types. The forest-shrubland-scrubland distinction was the most apparent one. Despite similarities in the woody species richness and Shannon diversity, open and closed vegetation states of forests and shrublands also differed regarding the density and cover of mature individuals and the density of saplings in different functional groups. Non-metric multidimensional scaling analyses and indicator species analyses also indicated clear distinctions among physiognomic vegetation types and openness states. Our findings indicate the necessity of a more complex description of vegetation types in the Mediterranean Basin. The results suggest that open and closed vegetation states of forests and shrublands are functionally distinct vegetation types.

Greater loss and fragmentation of savannas than forests over the last three decades in Yunnan Province, China

Yunnan Province, southwest China, has a monsoonal climate suitable for a mix of fire-driven savannas and fire-averse forests as alternate stable states, and has vast areas with savanna physiognomy. Presently, savannas are only formally recognised in the dry valleys of the region, and a no-fire policy has been enforced nationwide since the 1980s. Misidentification of savannas as forests may have contributed to their low protection level and fire-suppression may be contributing to vegetation change towards forest states through woody encroachment. Here, we present an analysis of vegetation and land-use change in Yunnan for years 1986, 1996, 2006, and 2016 by classifying Landsat imagery using a hybrid of unsupervised and supervised classification. We assessed how much savanna area had changed over the 3 decades (area loss, fragmentation), and of this how much was due to direct human intervention versus vegetation transition. We also assessed how climate (mean annual temperature, aridity), landscape accessibility (slope, distance to roads), and fire had altered transition rates. Our classification yielded accuracy values of 77.89%, 82.16%, 94.93%, and 86.84% for our four maps, respectively. In 1986, savannas had the greatest area of any vegetation type in Yunnan at 40.30%, whereas forest cover was 30.78%. Savanna coverage declined across the decades mainly due to a drop in open parkland savannas, while forest cover remained stable. Savannas experienced greater fragmentation than forests. Savannas suffered direct loss of coverage to human uses and to woody encroachment. Savannas in more humid environments switched to denser vegetation at a higher rate. Fire slowed the rate of conversion away from savanna states and promoted conversion towards them. We identified remaining savannas in Yunnan that can be considered when drafting future protected areas. Our results can inform more inclusive policy-making that considers Yunnan’s forests and savannas as distinct vegetation types with different management needs.