Deciduous Broad-leaved Forest Research Articles

Temporal and Spatial Evolution Characteristics and Its Driving Mechanism of Land Use/Land Cover Change in Laos from 2000 to 2020

Land use/land cover change (LUCC) research is of great significance to land conservation and regional sustainable development. At present, there is a lack of research on the long-term timing of the change process and mechanisms of LUCC that accords with the national level in Laos. Based on the Global Land-Cover product with the Fine Classification System at 30 m (GLC_FCS30) data set as well as economic and social statistical data, the authors analyzed the spatiotemporal regularity and driving mechanism of LUCC in Laos from 2000 to 2020 by using dynamic degree, flow direction analysis, principal component analysis, correlation analysis and other methods. The results show that: (1) Laos is rich in natural ecological resources. In 2020, the forest and shrubland areas accounted for 53.3% and 32.4% of the land area, respectively; (2) from 2000 to 2020, the rate of LUCC across the country continued to rise, and the integrated dynamic degree of LUCC was 14.4%. The change in impervious surfaces is the most drastic. The area of evergreen broad-leaved forest, evergreen needle-leaved forest and grassland continued to shrink, while the area of rainfed cropland, irrigated cropland, deciduous broad-leaved forest, shrubland, wetland and the water body continued to expand; (3) the LUCC process mainly occurred between forest, shrubland and cropland. The LUC with the largest transfer out area is evergreen broad-leaved forest (8.91 × 103 km2), and the LUC with the largest transfer into the area is shrubland (8 × 103 km2); (4) in the past 20 years, the LUCC process in Laos has been mainly affected by macro-socioeconomic development, agricultural development, and forestry development. The population is the key factor driving LUCC in Laos. This study can provide decision-making support for the rational planning and utilization of land resources in Laos.

Tree species richness as an important biotic factor regulates the soil phosphorus density in China's mature natural forests

Tree species richness has been recognized as an underlying driving factor for regulating soil phosphorus (P) status in many site-specific studies. However, it remains poorly understood whether this is true at broad scales where soil P strongly rely on climate, soil type and vegetation type. Here, based on the data of 946 mature natural forest sites from a nationwide field survey in China, we analyzed the impact of tree species richness on soil P density of China's mature natural forests (deciduous coniferous forest, DCF; evergreen coniferous forest, ECF; deciduous broad-leaved forest, DBF; evergreen broad-leaved forest, EBF; and mixed coniferous and broad-leaved forest, MF). Our results showed that tree species richness had a negative effect on soil P density in China's mature natural forests. The Random Forest regression model showed that the relative importance of tree species richness to soil P density was second only to the climate factors (mean annual temperature, MAT; mean annual precipitation, MAP). In addition, the structural equation model (SEM) results showed that the goodness fit of SEM increased when the tree species richness was included into the model. These results suggested that tree species richness was an important factor in regulating the China's mature natural forests soil P density. Furthermore, the SEM results showed that the decreased soil P density was related to the increase in ANPP and the decrease in litter P concentration induced by tree species richness. This result indicates that tree species richness could facilitate plant P absorption and inhibit plant P return into the soil, and thus reducing the soil P density in China's mature natural forests. In conclusion, we found tree species richness was an important biotic factor in regulating soil P density at broad scales, which should be fully considered in Earth models that represent P cycle.

Forest density and edge effects on soil microbial communities in deciduous forests across Europe

Forest fragmentation increases the proportion of edge area and this, in turn, induces changes in forest structure, species composition and microclimate. These factors are also strongly determined by the forest management regime. Although the interactive effects of edges and density on forest plant communities have been extensively studied, little is known about the response of the belowground communities. Here we investigated the variation of soil microbiota in 45 deciduous broadleaved forests along a latitudinal gradient from Italy to Norway at a continental scale across Europe. Phospholipid fatty acid (PLFA) and neutral lipid fatty acid (NLFA) were used to map the microbial community in the forest edge and interior across three forest densities (dense, intermediate, open forest). Microbial community composition was only affected by forest edge effects and not by forest density. We did not find any interaction effects between forest density and distance-to-edge. Arbuscular mycorrhizal fungi (AMF) were significantly more abundant in edges and Gram-negative bacteria more abundant in interiors, respectively. The microbial community composition was closely related to soil pH, soil potassium and nitrogen, texture (percent sand) and soil temperature. Soil pH was positively correlated with the saprotrophic fungi and potassium was positively correlated with Gram-negative bacteria but negatively correlated with Actinobacteria. In sum, we reveal the notable effects of forest edges on the soil AMF abundance. This result indicated that AMF could possess a stronger affinity with species growing in the edges, which may help to improve plant performance under hostile conditions herein.

Key drivers of soil arthropod community shift across a subalpine forest series vary greatly with litter and topsoil layers

Soil arthropods play crucial roles in carbon and nutrient cycling in forest ecosystems. The structure and biodiversity of soil arthropod communities may vary considerably with forest succession and across soil layers due to changes in key drivers, which needs to be fully investigated. Arthropod communities in both litter and topsoil (0–5 cm) layers were simultaneously investigated in the subalpine deciduous broadleaved shrub (S1) and forest (S2), coniferous and broadleaved mixed forest (S3), and half-mature (S4), mature (S5), and overmature (S6) coniferous forests in Wanglang National Nature Reserve. The dominant taxa and common taxa in litter and topsoil layers shifted with forest succession. The litter layer had the most fungivores and saprophages, while the topsoil layer had the most saprophages. From S1 to S4, individual densities and functional groups of soil arthropod declined, then increased continuously. The Shannon-Wiener index, Pielou index, and Margalef index of arthropod communities in litter and topsoil layers declined from S1 (S2) to S4, then increased; for each functional group in the topsoil layer, these indices varied more significantly with forest succession than those in the litter layer. The structure and diversity of the soil arthropod community in the litter layer were significantly influenced by coarse woody debris stock, and those in the topsoil layer were significantly influenced by canopy density and the C/N ratio, based on RDA analysis. In conclusion, the key drivers of arthropod community shift with forest succession differed between litter and topsoil layers, which allowed arthropod communities to show different sensitivity to the environment change. This study contributes to an in-depth understanding of the ecological impact of forest succession changes on soil arthropods.

Thermal Regulation of Coastal Urban Forest Based on ENVI-Met Model—A Case Study in Qinhuangdao, China

Urban forests can improve human comfort by improving the near-surface microclimate. Exploring the microclimate characteristics of urban forests and their impact on human comfort is particularly important to improve the urban thermal environment through scientific urban forest design. Since most previous studies were conducted under typical inland urban climates and little is known about the thermal regulation services of coastal urban forests, this study field measured the thermal surface radiation temperature of 16 open spaces in the urban forest site in Qinhuangdao. Then the ENVI-met software was used to simulate and analyze the microclimate characteristics before and after the park’s building-up, and compare the differences in the human comfort index in different scenarios. Results indicated that: (1) Vegetation have a significant cooling effect on surrounding environment. The farther away from vegetation area, the higher the average surface temperature. (2) Water bodies have the best cooling and humidifying effect on the 9–18 m surrounding environment with the best human comfort index. (3) In summer, air temperature in park decreased by 0.4~1.4 °C, and the relative humidity increased by 0.07~2.81%. (4) After the park’s built-up, the average human comfort index was optimized by 0.02~1.87. Arranging the leisure open space around the water bodies and forest edge space of the deciduous broad-leaved forest could improve human comfort. This research is expected to provide a scientific basis and planning inspiration for the construction of coastal urban forests in the same latitude area.

Temporal Partitioning of Fungal Sporophores in a Temperate Deciduous Broad-Leaved Forest

The temporal partitioning hypothesis refers to the promotion of stable species’ coexistence by reducing the likelihood of competitive exclusion, such as when species are active at different months of the year. However, the studies confirming the mechanisms of species’ coexistence focus on spatial scale, and temporal partitioning hypothesis for species’ coexistence remains underexplored. Fungal sporophores that are sensitive to seasonality change are ideal candidates for studying the role of temporal differentiation hypothesis in species’ coexistence. In this study, a field survey of fungal sporocarps was conducted from May to October, and the entity and abundance of different species of fungal sporocarps in a 5-hectare forest dynamic plot in a temperate, deciduous broad-leaved forest were recorded. The results showed that the emergence of fungal sporocarps based on month was highly specialized and uneven. The torus-translation test showed that 56 species exhibited ecological habitat preferences for different months (47/100, 47%). The distribution of soil fungal sporocarps (35/75, 46.67%) based on months showed higher specialization compared with that of rotten-wood fungal sporocarps (9/22, 40.90%). The findings suggest the importance of temporal partitioning in maintaining local diversity in the fungal community.

Disentangling the effects of biotic neighbors and habitat heterogeneity on seedling survival in a deciduous broad-leaved forest

In forest ecosystems, seedling dynamics play a critical role in understanding species coexistence and community assembly. Exploring the effects of key factors on seedling survival can therefore offer key insights into how they interact to affect seedling mortality in natural forests. Based on 5 years of woody seedling census data and tree census data from a 25-ha permanent forest plot in the subtropical-temperate transitional region in the Qinling Mountains of north-central China, we examined the effects of biotic neighborhood processes and habitat heterogeneity as well as their interactions on seedling mortality using survival data of 11,408 seedlings of 69 species (i.e., 30 tree species and 39 shrub species). The results showed that negative density-dependence (NDD) had significant effects on seedling dynamics and survival at community level. Both biotic and abiotic factors affected seedlingsurvival at different ages, but the influence of negative density-dependence was much more significant, especially on the tree seedlings ≥ 5 years old. For the shrub seedlings, however, biotic factors had a larger effect on their survival than abiotic factors. Thus, we concluded that both habitat heterogeneity and negative density-dependent mortality shaped species coexistence at the seedling stage in the deciduous broad-leaved forest.

Stand carbon storage and net primary production in China’s subtropical secondary forests are predicted to increase by 2060

BackgroundForest ecosystems play an important role in carbon sequestration, climate change mitigation, and achieving China's target to become carbon (C) neutral by 2060. However, changes in C storage and net primary production (NPP) in natural secondary forests stemming from tree growth and future climate change have not yet been investigated in subtropical areas in China. Here, we used data from 290 inventory plots in four secondary forests [evergreen broad-leaved forest (EBF), deciduous and evergreen broad-leaved mixed forest (DEF), deciduous broad-leaved forest (DBF), and coniferous and broad-leaved mixed forest (CDF)] at different restoration stages and run a hybrid model (TRIPLEX 1.6) to predict changes in stand carbon storage and NPP under two future climate change scenarios (RCP4.5 and RCP8.5).ResultsThe runs of the hybrid model calibrated and validated by using the data from the inventory plots suggest significant increase in the carbon storage by 2060 under the current climate conditions, and even higher increase under the RCP4.5 and RCP8.5 climate change scenarios. In contrast to the carbon storage, the simulated EBF and DEF NPP declines slightly over the period from 2014 to 2060.ConclusionsThe obtained results lead to conclusion that proper management of China’s subtropical secondary forests could be considered as one of the steps towards achieving China’s target to become carbon neutral by 2060.

Remote sensing of water use efficiency in Southwest China's karst area.

As the largest contiguous karst area in China, the southwestern karst area is a typical ecologically fragile area affecting local vegetation dynamics. Ecosystem water use efficiency (WUE) is an important factor reflecting the ability of vegetation to produce organic matter with a limited water supply. Therefore, determining the WUE variation trends in this ecologically fragile region is important. In this paper, we used MODIS remote sensing datasets, meteorological data, and land cover data to analyze the spatiotemporal changes in vegetation water use efficiency in the southwestern karst region from 2001 to 2017. We also further quantitatively analyzed the effects of climate change and human activities on the spatial and temporal patterns of vegetation WUE in the study area. The main conclusions were as follows. (1) From 2001 to 2017, in terms of temporal characteristics, the interannual variation in WUE fluctuated greatly, ranging from 1.33 to 1.51g C kg-1 H2O, with a multiyear average of 1.43g C kg-1 H2O and an average rate of change of - 0.0046g C kg-1 H2O year-1. In terms of spatial characteristics, areas with a higher WUE were concentrated in central Sichuan and northeastern Yunnan. (2) The annual average WUE of each vegetation type decreased in the following order: evergreen coniferous forest > evergreen broad-leaved forest > mixed forest > deciduous broad-leaved forest > cultivated land > deciduous coniferous forest > grassland > cultivated land and natural vegetation > shrub forest. (3) The vegetation WUE of 70.66% in this area was positively correlated with temperature. Additionally, 79.68% of the vegetation WUE was negatively correlated with precipitation. The relative contribution rates of climate change and human activities to the change trend in WUE were 15% and 85%, respectively. Compared with WUE results in other studies, the WUE of different karst landform areas obtained in this study was quite different, indicating that the geological and landform features of the karst area are complex. Our study provides scientific support for local vegetation restoration and protection policies and promotes the understanding of the principle of the carbon-water cycle in karst areas.

Plant–insect and –fungal interactions in Taxodium-like wood fossils from the Oligocene of southwestern China

Cupressaceae fossil tree stumps from the early Oligocene Lühe coal mine in southwestern China contain abundant quartz-petrified damage traces. The wood fossils were assigned to Taxodioxylon (very similar to extant Taxodium) based on wood anatomy analysis. Within the woods, three types of arthropods- and one fungus-mediated ichnofossils LHIF 1–4 (Lühe wood ichnofossils 1–4) were observed. The boring wood types for LHIF 1–3 are comparable to extant longicorn beetles (Cerambycidae), snout beetles (Curculionidae), and wood wasps (Siricidae). The polyporous structured traces of LHIF 4 were attributed to the invasion of stem canker fungus (Polyporaceae). This first-ever report of Taxodium-like fossil from the Oligocene of southwestern China points to Yunnan serving as a refugium for some lineage of gymnosperms at that time. Furthermore, the extensive traces of arthropods and fungus discovered from the fossil wood have filled a gap in fossil records for insect herbivory in this region. The wood stumps and decomposers suggest a swamp-like environment. The disappearance of Taxodium after the Oligocene supports incremental aridification and changes in winter season temperature conditions, which shifted the late Paleogene mixed deciduous broad-leaved and needle-leaved forest into the present evergreen broad-leaved forest.

Changes in the soil nematode community among climate zones do not keep pace with changes in plant communities

Revealing the distribution patterns of soil nematode communities among climate zones helps uncover the spatial distribution patterns of belowground biodiversity. The aims of this study were to reveal the spatial distribution patterns of the taxonomic composition, diversity and trophic structure of soil nematode communities among continuous climate zones. Investigations were conducted for five altitudinal vegetation types, i.e., subtropical evergreen broad-leaved forest (SEB), subtropical evergreen and deciduous broad-leaved mixed forest (SEDB), warm temperate deciduous broad-leaved forest (WTDB), mid-temperate coniferous and broad-leaved mixed forest (MTC) and cold temperate coniferous forest (CTC), on the eastern slope of Gongga Mountain from 2014 to 2017. The taxonomic compositions of the soil nematode communities in the SEDB, WTDB, MTC and CTC were similar but differed markedly from that in the SED, with patterns varying among sampling years. Abundances and diversity showed unimodal distribution patterns, with maximum values occurring in the WTDB. The abundances of the four trophic groups varied significantly among the vegetation types. Relative abundances stabilized for bacterivores and plant parasites but declined for fungivores and increased for omnivores-predators from the SEB to the CTC. The ratio of fungivores to bacterivores in the SEB was significantly higher than those in the other vegetation types, implying that the trophic structure and material cycling channels differed among forest types. The spatial distribution of the soil nematode communities was mainly influenced by pH, total K, total P and soil temperature. These findings suggested that the taxonomic composition, abundance, diversity and trophic structure of soil nematode communities vary among climate zones, but the changes in the soil nematode communities among climate zones did not keep pace with those in aboveground plant communities.

Characteristics of Soil Mites Communities Structure under Vegetation Vertical Gradient in the Shibing World Natural Heritage Property, China

In montane environments, as elevation increases, the combination of hydrothermal factors changing and vegetation types changing can cause changes to the soil mite community. To reveal the influence of different vertical vegetation types on the structure and diversity of soil mite communities in the Shibing Karst World Natural Heritage Property, in September 2021, specimen collection and identification of soil mites were carried out under the four typical vegetation zones of coniferous broad-leaved mixed forests (CBF), evergreen broad-leaved forests (EBF), deciduous broad-leaved forests (DBF), and river beach scrubs (RBS) in the Heritage Property. This occurred in order to analyze the community structure of soil mites. A total of 10,563 soil mites were captured in this region, belonging to 3 orders, 67 families, 137 genera; Perscheloribates and Scheloribates are the dominant groups in the area. The number of soil mite genera (CBF > EBF > DBF > RBS) and the number of individuals (RBS > DBF > CBF > EBF) differed between vegetation types. The dominant soil mite genera were not entirely consistent, with the highest values for each soil mite community diversity parameter being in the EBF habitat. The number of soil mite genera and individuals differed among vegetation types in different soil layers. It showed an apparent aggregation towards the surface layer, with complex diversity and richness indices changes. The highest community similarity indices were found between CBF and DBF, which were moderately similar. The cluster analysis results further showed that soil mite communities differed in different vegetation zones and among the same vegetation zones. The predatory gamasid mite structure is mainly r-selective. The ecological groups of oribatid mites are all O-type in the number of groups and P-type in the number of individuals. Lasiobelba, Nanhermannia, Tectocepheus, and Mochlozetes, among others, represent the group of nutrient functions that make up the soil mites in the study area. The study shows that the soil mite community of the Shibing Karst World Natural Heritage Property is rich in groups and shows gradient differences with the vegetation spectrum, and based on the unique subtropical canyon karst habitat of the Heritage Property, the community structure of soil mites will be in the process of adaptation and dynamic change, so long-term dynamic monitoring and in-depth study of the soil mites community structure of the Heritage Property are needed.

Habitat characteristics of <i>Shortia uniflora</i> as a local resource plant with the flower landscape in Tomiyama-funato district, Nakagawa Town, Tochigi Prefecture.

This study examined the habitat characteristics of Shortia uniflora, which is one of the main attractors of flower tourism in hilly and mountainous areas. Due to the distribution and vegetation surveys around the open flowering site, nine colonies with areas of 300–700 m2 and some above 1000 m2 were found in addition to seven colonies with an areas of 50–200 m2. The results revealed that S. uniflora prefers steep, upper parts of the north-facing slope and avoids the cedar forest with many litters. The communities were also commonly distributed within evergreen cypress forests, which were deciduous broadleaf forests 70 years ago, in 1950. Regardless of the type of forest canopy (cypress forest, including the open flowering site, and deciduous broad-leaved forest), the floristic composition was dominated by common species. This species is shade-tolerant and has continued to grow in the forest even after the conversion to cypress forest. The area of the community in the open flowering site was 8,000 m2, and the community size was much larger than other surrounding communities. The extremely large size of the community is a result of the continuous appropriate forest floor management according to the habitat characteristics, and the flowering landscape was evaluated as a local resource based on the ecological and sociological area-context.

Changes in carbon inputs affect soil respiration and its temperature sensitivity in a broadleaved forest in central China

Soil respiration, as an important process in global carbon cycle, is drastically stimulated by warming. Changing plant carbon inputs caused by intensified human disturbances and climate change can complexly influence soil respiration and its temperature sensitivity (Q10). Although a number of experiments have been established in the world to explore the effects of changing carbon inputs, it remains a challenge to predict the direction and magnitude of changes in soil respiration and Q10 due to high spatiotemporal variability of climatic zone and ecosystem. Therefore, we conducted a field manipulative experiment to examine the impact of litter removal and root exclusion on soil respiration and Q10 in a deciduous broad-leaved forest in transition zone between subtropical and warm temperate zone. The results showed that litter removal significantly reduced soil respiration, microbial biomass carbon, soil organic carbon, total nitrogen and soil moisture. In addition, litter removal altered soil microbial community composition, expressed in increase of Gram-positive / Gram-negative bacteria ratio and percentage of actinomycetes, and enhanced microbial physiological stress index. Root exclusion significantly increased Q10 by elevating soil C/N ratio, which supporting “C quality-temperature” hypothesis. The study indicates that root exclusion may accelerate soil respiration under warming. Our study provides insights to improve carbon cycling models and accurately predict the consequences of climate change.

Response of soil microbial community to plant composition changes in broad-leaved forests of the karst area in Mid-Subtropical China.

The rapid growth and expansion ofCryptomeria japonica (Thunb. ex L. f.) D. Don in karst area strongly affects plant composition of native deciduous broad-leaved forest, which seriously threat ecosystem function and service. Given the importance of soil microorganisms in regulating nutrients cycling and plant species coexistence, understanding soil microbial attributes and their relationships with soil and vegetation features in forests harboring different C. japonica abundance will help understanding the drivers of ecosystem function changes. Here we examined the diversity and composition of soil bacterial and fungal communities and their correlations with plant diversity as well as soil physicochemical properties in karst broad-leaved forests with different relative abundances of C. japonica (i.e., a high, moderate, low and no proportion level with a stem density of 1,487, 538, 156 and 0 plant/hm2, respectively) in Mid-Subtropical China. We found that soil pH decreased while soil water content (SWC), total nitrogen (TN), total phosphorus (TP) and total potassium (TK) tended to increase with the increase in C. japonica abundance. In contrast, soil available nitrogen (AN), available phosphorus (AP) and available potassium (AK) content declined by 26.1%∼49.3% under the high level of C. japonica abundance. A gradual decrease in relative abundance of Acidobacteria and Chloroflexi while a pronounced increase in relative abundance of Ascomycota and Basidiomycota were observed with increase of C. japonica abundance. Alternations in bacterial composition were closely related to changes in AP and AK, while the change of fungal structure was mainly related to SWC, soil organic carbon (SOC) and pH, indicating that bacterial community was sensitive to declines in soil available nutrients and fungal structure was sensitive to changes in soil physicochemical properties (i.e., pH and SWC) and organic carbon resource. Understory plants had the highest α-diversity in forest containing moderate abundance of C. japonica, which might be related to the high bacterial diversity. Our findings suggest conservation of soil bacterial and fungal taxa that are responsible for nutrients availability and carbon sequestration is of great significance for improving the resistance of natural deciduous broad-leaved forests to the rapid spread of C. japonica in karst areas. Moreover, Acidobacteria, Chloroflexi, Ascomycota and Basidiomycota are potential indicators for soil properties changes, which should be taken into consideration in karst forest managements.

Study of the Effect of Vegetation on Reducing Atmospheric Pollution Particles

Atmospheric particulate matter (PM) is a major air pollutant. PM2.5 and PM10 pose particularly serious threats to the ecological environment and human health. Vegetation plays an important role in reducing the concentration of particles. Based on a long time series of air quality, meteorological, and vegetation coverage data in the Beijing–Tianjin–Hebei (BTH) region, the present paper evaluated the influence at the overall and built-up area scales and quantified the process involved in the dry settlement of particles on vegetation based on a mathematical model. The experimental results showed that (1) the total amounts of PM10 reduced by vegetation in the BTH area were 505,200 t, 465,500 t, 477,200 t and 396,500 t in 2015, 2016, 2017 and 2018, respectively, and the total amount of PM2.5 was reduced by 19,400 t, 19,200 t, 16,400 t and 12,700 t, respectively. The annual reduction in PM10 and PM2.5 from 2015 to 2018 by vegetation in the BTH region showed a downwards trend, and the annual reduction was mainly caused by the significant decrease in PM concentration. (2) More than 80% of the reduction in annual yield was concentrated in May–September, and a large leaf area was the main reason for the largest yield reduction in the growing season. The efficiency of PM reduction in forestland was approximately five–seven times that in grassland, and the deciduous broad-leaved forest was the main driver of this reduction in each forest. (3) The reduction in PM10 by vegetation was approximately 30 times that of PM2.5. However, the reduction in PM2.5 by vegetation should not be ignored because PM2.5 has a stronger correlation with human production and living activities. Increasing the area and density of green space via afforestation, returning farmland to forest and giving full play to the self-purification function of green spaces are very important to reducing and controlling the concentration of PM.

Mid-Holocene European climate revisited: New high-resolution regional climate model simulations using pollen-based land-cover

Land-cover changes have a clear impact on local climates via biophysical effects. European land cover has been affected by human activities for at least 6000 years, but possibly longer. It is thus highly probable that humans altered climate before the industrial revolution (AD1750–1850). In this study, climate and vegetation 6000 years (6 ka) ago is investigated using one global climate model, two regional climate models, one dynamical vegetation model, pollen-based reconstruction of past vegetation cover using a model of the pollen-vegetation relationship and a statistical model for spatial interpolation of the reconstructed land cover. This approach enables us to study 6 ka climate with potential natural and reconstructed land cover, and to determine how differences in land cover impact upon simulated climate. The use of two regional climate models enables us to discuss the robustness of the results. This is the first experiment with two regional climate models of simulated palaeo-climate based on regional climate models.Different estimates of 6 ka vegetation are constructed: simulated potential vegetation and reconstructed vegetation. Potential vegetation is the natural climate-induced vegetation as simulated by a dynamical vegetation model driven by climate conditions from a climate model. Bayesian spatial model interpolated point estimates of pollen-based plant abundances combined with estimates of climate-induced potential un-vegetated land cover were used for reconstructed vegetation. The simulated potential vegetation is heavily dominated by forests: evergreen coniferous forests dominate in northern and eastern Europe, while deciduous broadleaved forests dominate central and western Europe. In contrast, the reconstructed vegetation cover has a large component of open land in most of Europe.The simulated 6 ka climate using reconstructed vegetation was 0–5 °C warmer than the pre-industrial (PI) climate, depending on season and region. The largest differences are seen in north-eastern Europe in winter with about 4–6 °C, and the smallest differences (close to zero) in southwestern Europe in winter. The simulated 6 ka climate had 10–20% more precipitation than PI climate in northern Europe and 10–20% less precipitation in southern Europe in summer. The results are in reasonable agreement with proxy-based climate reconstructions and previous similar climate modelling studies. As expected, the global model and regional models indicate relatively similar climates albeit with regional differences indicating that, models response to land-cover changes differently.The results indicate that the anthropogenic land-cover changes, as given by the reconstructed vegetation, in this study are large enough to have a significant impact on climate. It is likely that anthropogenic impact on European climate via land-use change was already taking place at 6 ka. Our results suggest that anthropogenic land-cover changes at 6 ka lead to around 0.5 °C warmer in southern Europe in summer due to biogeophysical forcing.

Middle Eocene Paleoenvironmental Reconstruction in the Gonjo Basin, Eastern Tibetan Plateau: Evidence From Palynological and Evaporite Records

The early uplift of the Tibetan Plateau (TP) had a profound influence on the paleoenvironment and paleoclimate. However, we still have little information about the link between the paleoclimatic changes and flora ecosystem caused by the uplift. The Eocene fluvial-lacustrine sequences in the Gonjo Basin, eastern TP, provide excellent archives of the paleoecological and paleoclimatic responses to the surface uplift of the TP. In this study, we investigated a section of the middle Eocene Ranmugou Formation (47.8–>44 Ma) and used the sporomorphs assemblages, sedimentology, and geochemistry of the evaporites to reconstruct the paleoclimate and paleovegetation. The palynological assemblages and coexistence analysis reveal that the middle Eocene ecosystem in the Gonjo Basin was dominated by warm and humid temperate deciduous broad-leaved forests. The 87Sr/86Sr ratios (0.709942–0.710062) of all of the gypsum samples are higher than those of contemporaneous seawater, while the δ34S values (10.3–11.0%) are much lower, indicating a lacustrine environment. Combined with published palynological and paleoelevation data for eastern Tibetan lacustrine basins, we infer that the paleoenvironment changed from warm and humid deciduous broad-leaved forests during 47.8–>44 Ma, to cool and arid temperate forest during 44–40 Ma in the Gonjo Basin, and to arid and cool steppe-desert vegetation in the late Eocene Nangqian Basin. The changes in the paleoclimate and vegetation were primarily driven by the surface uplift of the Central Watershed Mountain, the high topography of which blocked the moisture from the Asian Eocene monsoon.

Effects of different vegetation restoration on soil nutrients, enzyme activities, and microbial communities in degraded karst landscapes in southwest China

The karst area in southwestern China is one of the largest and continuous karst landforms in the world, and its ecosystem is highly sensitive and fragile. Appropriate vegetation restoration modes are of great significance for sustaining and improving the stability of the karst ecosystem, the dominant landform type in southwest China. Bacteria, linking soil and plants, play an important role in regulating the succession and restoration of karst vegetation. However, it remains unclear how soil bacterial communities and soil biochemical properties respond to vegetation restoration practices in karst areas. In this study, a 13-year long-term trial was performed using three planting restoration modes of deciduous broad-leaved, mixed evergreen and deciduous broad-leaved forest, and evergreen broad-leaved forests, with controls of natural enclosure. We aimed to investigate the impact of different vegetation restoration modes on the structure of soil microbial communities and their driving mechanisms using 16S rDNA Illumina sequencing, combined with the determination of 11 soil indicators and statistical models. The results showed that artificial restoration can improve soil nutrient contents, enzyme activities and microbial biomass more effectively than natural closure, which is beneficial to the rapid restoration of vegetation after abandoning of farmland. Among them, the effect of deciduous broad-leaved treatment on artificial restoration mode was better than that of mixed evergreen and deciduous broad-leaved forest and evergreen broad-leaved forest. In sequencing results, artificial restoration increased the relative abundance of Proteobacteria, but decreased that of Acidobacteria. In addition, pH, soil microbial biomass carbon, and urease activity significantly increased bacterial diversity. Different vegetation restoration measures significantly changed the soil bacterial community structure. The bacterial community of deciduous broad-leaved forest was the most beneficial to the benign development of soil. Mantel test showed that pH and soil microbial biomass carbon and nitrogen were the key driving factors of the soil bacterial community. FAPROTAX analysis showed a significant positive correlation between sucrase activity and phototrophy functional bacteria. The results demonstrated that compared with natural enclosure, artificial vegetation restoration promoted rapid community succession, and construction of deciduous broad-leaved forest was the most effective way to manage karst areas, improve soil nutrients, alter its key microbial populations, promote ecosystem services, and eventually benefit the restoration of vegetation in karst areas.

Restoring Natural Forests as the Most Efficient Way to Water Quality and Abundance: Case Study from Želivka River Basin

This article shows how to restore Central European natural capital effectively. Water in the landscape is primarily sustained by vegetation and soil, most effectively by natural forests and only secondarily by artificial reservoirs. The authors document these facts using a case study from the Želivka River basin (Švihov reservoir), which collects surface water for the metropolitan region of Prague and Central Bohemia. With the Energy-Water-Vegetation Method, the authors demonstrate that the cultural human-changed landscape of the Želivka river basin is able to utilize only about 60% of its solar energy potential. In 1.5% of the territory of the Czech Republic, society annually loses supporting ecosystem services at a level higher than 25% of the annual GDP of the CR 2015. Water retention in the landscape needs to be re-evaluated and addressed in accordance with the thermodynamic principles of life and ecosystem functioning in the biosphere. It is necessary to begin restoring the most efficient natural capital in the landscapes and to return the broad-leaved deciduous forests by intelligent forestation methods to the cultural landscape to the extent justified; this is especially true of the Želivka River basin, which is Czechia’s biggest surface drinking-water collecting area.