Mountain Coniferous Forests Research Articles

Surface soil phytolith assemblages across an altitudinal transect in the Qilian Mountains of Northwestern China, and their implications for palaeoecologic analysis in arid alpine regions

Reconstructing changes in altitudinal vegetation belts is crucial for comprehending vegetation response to past environmental changes in arid alpine regions, however, proxy data are limited. In this study, we report 51 surface soil phytolith samples from various vegetation types across an altitudinal transect in the arid alpine region of the Qilian Mountains, to elucidate the relationships between vegetation types and phytolith assemblages. Our results show that phytolith morphotypes in surface soil samples could be categorized into 16 classes, with Gobbet, Crenate, Rondel, Elongate entire, and Acutebulbosus being the predominant classes. The characteristics of surface soil phytolith assemblages vary across an altitudinal transect, reflecting differences in local vegetation. Discriminant analysis identifies Cubic, Elongate entire, Crenate, Gobbet, and Rondel as discriminant variables that correlated with five vegetation types (desert vegetation, mountain steppe vegetation, mountain coniferous forest vegetation, subalpine shrub meadow vegetation, and alpine meadow vegetation). We establish five discriminant functions based on the relationships between vegetation types and phytolith assemblages, demonstrating a high accuracy of our method for distinguishing between different vegetation types. These discriminant functions are applicable for distinguishing between diverse vegetation types in the mountains of arid inland regions of Asia. They are also effective in identifying coniferous forest vegetation in mid-latitude mountains. Therefore, these discriminant functions hold significant potential for reconstructing changes in altitudinal vegetation belts in mountainous regions and determining the vegetative types recorded by terminal lakes in arid regions. Our study introduces a new perspective on palaeoecologic analysis in arid alpine regions, advancing our understanding of ecosystem dynamics in response to environmental fluctuations.

Onset of aridification in mid-latitude Asia at 41 Ma linked to the proto-Paratethys Sea retreat

The initial aridification of mid-latitude Asia is thought to be one of the most prominent Cenozoic environmental changes in Asia. However, precisely dated, fine-grained sediments documenting initial aridity beyond central Asia are extremely rare. Here, we reconstruct the history of Middle-Late Eocene (47.8–37.8 Ma) hydroclimate change in northeast China using continuous palynological records from a lacustrine sedimentary sequence in the Fushun Basin. Our results indicate that the onset of aridification occurred concurrently with increased climatic variability at 41.2 Ma, as expressed by a sharp increase in xerophytic Ephedra and mountainous coniferous forest at the expense of an abrupt decrease in broadleaved forest, along with frequent alternations between semi-desert and swamp forest vegetation after 41.2 Ma. The climate changed markedly from a stable, warm-wet climate during the Middle Eocene to a cooler, drier climate with pronounced warm-dry and cold-wet oscillations during the Late Eocene. This finding challenges the previously prevailing idea that the East Asian monsoon was significantly enhanced in northeast China after 41–40 Ma. A comprehensive comparison of records from eastern and central Asia demonstrates that the onset of aridification and enhanced climate variability after 41 Ma were widespread across mid-latitude Asia. This may be explained by reduced moisture transport by the westerlies and strengthening of high- and low-latitude forcing linked to the coeval retreat of the proto-Paratethys Sea.

Snow accumulation and ablation measurements in a midlatitude mountain coniferous forest (Col de Porte, France, 1325 m altitude): the Snow Under Forest (SnoUF) field campaign data set

Abstract. Forests strongly modify the accumulation, metamorphism and melting of snow in midlatitude and high-latitude regions. Recently, snow routines in hydrological and land surface models were improved to incorporate more accurate representations of forest snow processes, but model intercomparison projects have identified deficiencies, partly due to incomplete knowledge of the processes controlling snow cover in forests. The Snow Under Forest (SnoUF) project was initiated to enhance knowledge of the complex interactions between snow and vegetation. Two field campaigns, during the winters 2016–2017 and 2017–2018, were conducted in a coniferous forest bordering the snow study at Col de Porte (1325 m a.s.l., French Alps) to document the snow accumulation and ablation processes. This paper presents the field site, the instrumentation and the collection and postprocessing methods. The observations include distributed forest characteristics (tree inventory, lidar measurements of forest structure, subcanopy hemispherical photographs), meteorology (automatic weather station and an array of radiometers), snow cover and depth (snow pole transect and laser scan) and snow interception by the canopy during precipitation events. The weather station installed under dense canopy during the first campaign has been maintained since then and has provided continuous measurements throughout the year since 2018. Data are publicly available from the repository of the Observatoire des Sciences de l'Univers de Grenoble (OSUG) data center at https://doi.org/10.17178/SNOUF.2022 (Sicart et al., 2022).

Tuber wenchuanense, a holarctic truffle with a wide range of host plants and description of its ectomycorrhiza with spruce

Tuber wenchuanense ascomata (Ascomycota, Pezizales), a species originally described from Sichuan (China), were found in the Tatra Mountains in southern Poland. The purpose of this work was to (i) report and assess the first case of the holarctic natural distribution of a Tuber species, (ii) amend the original description of the species, (iii) summarize data on its host plants and (iv) describe its ectomycorrhiza. Specimens of Tuber wenchuanense from the Tatra Mountains were studied morphologically and molecularly. The ectomycorrhiza of this truffle with Picea abies was described for the first time. The distribution of T. wenchuanense, which is reconstructed based on sequences deposited in the publicly available nucleotide sequence databases, makes it the first holarctic Tuber species and the one with the northernmost habitat. In fact, its habitat is confined mainly to mountain coniferous forests and alpine and arctic tundra; although, according to known observations, the fruiting bodies of T. wenchuanense can be produced only under conifers. Based on the sequences of the internal transcribed spacer, this species appears to have low genetic variability over the entire distribution range. The phylogenetic tree showed that some of the unidentified phylotypes from the Rufum clade found by other researchers belong to T. wenchuanense. The ecological implications of these findings are discussed.

Difference of soil carbon sequestration between rhizosphere and bulk soil in a mountain coniferous forest in southwestern China under nitrogen deposition

Difference of soil carbon sequestration between rhizosphere and bulk soil in a mountain coniferous forest in southwestern China under nitrogen deposition

Contrasting climate drivers of seasonal growth in western vs. eastern Mexican mountain conifer forests

Hydroclimate affects the radial growth responses of trees, but the drivers of their spatial and population variability are not sufficiently understood. We addressed this issue by sampling several conifer populations located at the same latitude, but at different longitude and elevation in western (W) and eastern (E) Mexican regions. We used dendroecology to disentangle how earlywood width (EW), latewood width (LW) and adjusted LW (LWadj), i.e. the residuals after removing EW influences on LW, responded to climate variables (temperature and precipitation), climate indices (Southern Oscillation Index, SOI, Niño 3.4, Pacific Decadal Oscillation, PDO) and a drought index (Standardised Precipitation-Evapotranspiration Index, SPEI). The W species (Pinus herrerae Martínez, Pinus durangensis Martínez, Abies durangensis Martínez and Cupressus lusitanica Mill.) showed lower growth rates than the E species (Pinus hartwegii Lindl., Picea mexicana Martínez, Pseudotsuga menziesii (Mirb.) Franco and Abies vejari Martínez). Growth in W benefits mostly from high precipitation in the prior winter and current spring and it is limited by high temperatures in spring, whereas growth in the E showed similar but weaker responses. Furthermore, positive (negative) correlations were found in radial growth with the Niño 3.4 (SOI) and the PDO from the prior to current autumns, which were again stronger in absolute terms in the W than in the E regions, excepting SOI in summer. In the W, P. durangensis and C. lusitanica were the least and most responsive species to spring drought, respectively; whilst P. menziesii and A. vejari were very responsive to spring drought compared to P. hartwegii in the E. Our results suggest greater responsiveness to hydroclimate and atmospheric patterns in the W than in the E region. These findings allow better interpretations of future changes in growth and composition in Mexican conifer forests, considering that climate models forecast warmer spring conditions and increased water shortage.

Catchment scale spatial distribution of soil enzyme activities in a mountainous German coniferous forest

Topography features within catchments influence soil properties, nutrient status, microbial dynamics and ultimately enzyme activities. Extracellular soil enzymes are essential for the decomposition of organic substrates and play a central role in global biogeochemical cycles. How topography and soil properties drive the spatial expression of enzyme activities at the catchment scale is still underexplored, especially in coniferous forest ecosystems. This study investigated the activity of four extracellular soil enzymes: β-glucosidase (β-glu), β-cellobiosidase (β-cello), acid phosphatase (pho) and leucine-aminopeptidase (l-leu) in Oh and Ah horizons of a (27 ha) mountainous coniferous forest catchment (Wüstebach, Eifel National Park, Germany). Spatial patterns and "hot spots" of activities of these four enzymes (involved in C-,N-, and P- cycling) were examined in connection to catchment units differing in slope, exposure and soil type (Cambisol vs. Gleysol), and multiple soil parameters (i.e., moisture content, pH, C, N, P, K, Fe, Mn content, C:N, C:P and N:P ratio). Catchment enzyme activities were overall, except for β-cello, significantly higher in the Oh than Ah horizon. Lower β-glu, and l-leu activities were found where more anaerobic soil conditions did occur, e.g., the river valleys (RV). Neither enhanced Oh horizon erosion on steeper Eastern (ES) and Northeastern (NES) slopes nor larger spatial soil nutrients heterogeneity on Northern (NS) and Western (WS) slopes, did significantly affect enzyme activity. Landscape topography did lead to a spatial variation of the activity of the four enzymes examined. The site-specific variation in C-cycling enzymes (β-glu and β-cello) was most marked at drier East, Northeast and Northern slopes, for P-cycling (pho) within the central wetter river valley but was for N-cycling (l-leu) enzyme activity more homogeneously distributed over the whole catchment. Overall, enzyme activities were strongly correlated to soil properties (especially soil moisture and organic carbon), but locations NS (Wüstebach source area) and RV (Wüstebach river flow path) showed less site-specific correlations. Further refinement of site-specific soil and external factors driving spatial distribution of enzyme activities at catchment scales and beyond will help to further tool up this research at larger spatial scales.

Microhabitat selection of blue eared pheasant (Crossoptilon auritum) during breeding period in Helan Mountains, China

Habitat degradation and fragmentation are crucial factors which result in biodiversity loss among the world. Understanding how species respond to the habitat change is helpful and essential for the conservation of the endangered ones. Therefore, the aim of current study is to explore how to carry out biodiversity conservation from the perspective of the habitat selection of species. We studied the microhabitat selection of blue eared pheasant ( Crossoptilon auritum) during its breeding time (including mating, incubation, and feeding periods). The field research was carried out from April to August in 2014 at Helan Mountains, China. Six nests of blue eared pheasants were found; 323 used plots and 171 control plots were recorded. Results indicated that blue eared pheasants prefer mountainous coniferous forest at shady slope with domination of Picea crassifolia, and its habitat selection was mainly influenced by shrub density, tree density, altitude, slope degree, hiding cover, water resource, and human disturbance. However, there were slight differences among the three periods. Our study firstly compared factors that affect the microhabitat selection of blue eared pheasants among the three periods of its breeding time. Meanwhile, combining the current study with the previous ones, specific strategies could be applied on the works of endangered species and biodiversity conservation.

변산반도국립공원 꽝꽝나무군락의 생태적 특성

In order to preserve and restore the habitats of Ilex crenata community distributed in Byeonsanbando National Park, the ecological characteristics of flora and major vegetation were investigated centered on the community distribution area. A total of 36 taxa with 22 families, 21 genera, 32 species, and 4 variants, were investigated in the vicinity of the Ilex crenata community. At close distances centered on the area around the Ilex crenata community, the vegetation was found to be a mountain coniferous forest called Pinus densiflora-Quercus serrata community(35° 39′ 18.62″ north latitude, 126° 34′ 56.70 east longitude), at an elevation of 85m to 95m above sea level, an inclination of 10° to 15°, and clustered around the south and southwest slopes. In the Tree-1 layer, there are Pinus densiflora, Quercus serrata, Quercus variabilis, and Prunus serrulata var. pubescens. In the Tree-2 layer, there are Quercus serrata, Quercus variabilis, Prunus serrulata var. pubescens, Styrax japonicus, and Acer pseudo-sieboldianum. In the Shrub layer, there are Ilex crenata, Rhododendron mucronulatum, Lespedeza maximowiczii, Fraxinus sieboldiana, Smilax china, Lindera obtusiloba, Fraxinus rhynchophylla, Rhododendron schlippenbachii, Lindera glauca, Juniperus rigida var. rigida. In the past, before the Buam Dam was built, the surrounding area was a rice paddy field and farmland, but after the Buam Dam was completed, due to changes in the climatic environment, such as fog and humidity, which occurred around the Buan Dam, It is predicted that changes in species composition within the community will appear as the blooming of Quercus serrata increases in the Tree-1 layer and Tree-2 layer, as Fraxinus sieboldiana, Fraxinus rhynchophylla, Lindera obtusiloba, etc. appear in the shrub layer, and Sasa borealis Indigofera kirilowii, Carex lanceolata, and Fraxinus sieboldiana, etc. appear in the herb layer. The distribution area of Ilex crenata community was measured to be 384㎡, the height of Ilex crenata was in the range of 2.2 to 2.5m, and the diameter of the rhizome of Ilex crenata community was Ø48.5mm+39.4mm+46.9mm+37.3mm, It is considered to be in good growth condition due to the stable management and protection of the colony area. In addition, as it is expected that Ilex crenata community will gradually spread as a constituent species of the shrub layer and the herbaceous layer in the pine and Ilex crenata community communities near the native habitats of the black oak community, a detailed investigation into these areas and monitoring for continuous conservation and restoration are needed in the future.

Potential microbial enzyme activity in seasonal snowpack is high and reveals P limitation

AbstractMicrobes in snow and ice ecosystems in polar regions contribute substantially to C, N, and P cycling, but few studies have explored microbial activity in seasonal snow. The purpose of this study was to explore the relative importance of snow microbial processing of C, N, and P compounds in atmospheric deposition and litter and detect elemental limitations of snow microbes in Rocky Mountain conifer forests. Enzyme activity in snow was orders of magnitude greater than activity reported for lentic and lotic waters in similar environments. Proportions of C/P‐ and C/N‐acquiring enzymes suggest that snow samples were P limited, or C and P co‐limited, while lentic and lotic waters were more N limited. As such, microbes in seasonal snow may change the composition of nutrients and carbon, but these processes are vulnerable to changes in atmospheric deposition and snow extent and duration, which could affect nutrient processing across large areas.

Plant trait filtering is stronger in the herb layer than in the tree layer in Greek mountain forests

We studied the differentiation among plant communities of deciduous broadleaved and mountain coniferous forests in terms of functional diversity and identity at a regional scale (northern and central Greece). We asked if patterns of functional differentiation among communities are consistent between the overstorey and understorey layers and if they can be influenced by deep past environmental conditions. Functional Richness (FRic) and Functional Dispersion (FDis), as well as their standardized effect sizes, were employed to assess the multivariate functional diversity of the community types. In contrast, single-trait Community Weighted Means (CWMs) were used as surrogates of functional identity. The aforementioned indices were calculated for three datasets, namely all the vascular plant taxa found in individual vegetation plots (total community), all phanerophyte (tree and shrub) taxa (overstorey) and all non-phanerophyte vascular plant taxa (understorey). We found that community types and especially four broad forest types (beech, ravine, pine and oak forests) are well differentiated in terms of functional composition (identity), as indicated by Non-Metric Multidimensional Scaling (NMDS). After conducting an NMDS for the three datasets, functional identity based on the total floristic composition was found to be the best discriminator of the studied communities. However, contrasting patterns were found for some specific traits or their categories between overstorey and understorey layers. The patterns of functional diversity of the community types (based on multivariate indices), revealed by calculating the standardized effect sizes of FRic and FDis based on the richness null model, did not differ substantially from random expectations for most of the studied community types when the dataset of all the vascular plant taxa was analyzed. However, the patterns revealed for the overstorey layer differed from those for the understorey layer. For the latter layer, the clustered structure was revealed in many community types based on the ses.FDis metric. Indications of deep past influence on the functional composition were found for certain community types (i.e. ravine forests) based on single-trait metrics, but no indication of such influence was found based on multivariate indices. Our findings highlight the complementarity and the additive explanatory value of the simultaneous use of single- and multi-trait approaches and their application to different layers in forests.

On the freeze–thaw cycles of shallow soil and connections with environmental factors over the Tibetan Plateau

Changes in the freeze–thaw cycles of shallow soil have important consequences for surface and subsurface hydrology, land–atmosphere energy and moisture interaction, carbon exchange, and ecosystem diversity and productivity. This work examines the shallow soil freeze–thaw cycle on the Tibetan Plateau (TP) using in–situ soil temperature observations in 0–20 cm soil layer during July 1982–June 2017. The domain and layer averaged beginning frozen day is November 18 and delays by 2.2 days per decade; the ending frozen day is March 9 and advances by 3.2 days per decade; the number of frozen days is 109 and shortens by 5.2 days per decade. Altitude and latitude combined could explain the spatial patterns of annual mean freeze–thaw status well. Stations located near 0 °C contour line experienced dramatic changes in freeze–thaw cycles as seen from subtropical mountain coniferous forest in the southern TP. Soil completely freezes from surface to 20-cm depth in 15 days while completely thaws in 10 days on average. Near-surface soil displays more pronounced changes than deeper soil. Surface air temperature strongly influences the shallow soil freeze–thaw status but snow exerts limited effects. Different thresholds in freeze–thaw status definition lead to differences in the shallow soil freeze–thaw status and multiple-consecutive-day approach appears to be more robust and reliable. Gridded soil temperature products could resolve the spatial pattern of the observed shallow soil freeze–thaw status to some extent but further improvement is needed.

Evaluation of Terra/Aqua MODIS and Sentinel-2 MSI NDVI data for predicting actual evapotranspiration in Mediterranean regions

ABSTRACT Conventional meteorological data and remotely sensed Normalized Difference Vegetation Index (NDVI) images can be proficiently combined to predict actual evapotranspiration (ETA) on different spatial and temporal scales. Up to now, however, the operational application of this approach in heterogeneous Mediterranean regions has found difficulty due to the insufficient spatial resolution of satellite sensors having high acquisition frequency (i.e. 250 m of Terra/Aqua Moderate Resolution Imaging Spectroradiometer, MODIS). The current study investigates the advantages brought for this objective by the recent availability of NDVI data taken from the Sentinel-2 MultiSpectral Instrument (MSI), which has a spatial resolution of 10 m. The investigation has been performed in two Mediterranean areas characterized by different spatio-temporal variability of vegetation cover. The first is a mountain coniferous forest, where such variability is low, while the second is a relatively small (around 10 ha) irrigated tomato field surrounded by other annual crops showing diversified growing cycles. An ETA estimation method based on NDVI data is applied in the two study areas and its performances are evaluated against ground references obtained through the elaboration of site measurements (i.e. meteorological, soil water content, and crop coefficient observations). The advantage of using MSI over MODIS NDVI images is marginal in the first case study, while is evident in the second. More particularly, such advantage is outstanding when the remote sensing method is applied in an operational mode, i.e. without using the information on the water supplied to the tomato crop by irrigation. This confirms that the utility of higher spatial resolution data is dependent not only on the fragmentation of the observed landscapes but also on the synchronicity of major vegetation growing cycles, which is influenced by both environmental and human-induced factors.

Predicting Emission Source Terms in a Reduced-Order Fire Spread Model—Part 1: Particulate Emissions

A simple, easy-to-evaluate, surrogate model was developed for predicting the particle emission source term in wildfire simulations. In creating this model, we conceptualized wildfire as a series of flamelets, and using this concept of flamelets, we developed a one-dimensional model to represent the structure of these flamelets which then could be used to simulate the evolution of a single flamelet. A previously developed soot model was executed within this flamelet simulation which could produce a particle size distribution. Executing this flamelet simulation 1200 times with varying conditions created a data set of emitted particle size distributions to which simple rational equations could be tuned to predict a particle emission factor, mean particle size, and standard deviation of particle sizes. These surrogate models (the rational equation) were implemented into a reduced-order fire spread model, QUIC-Fire. Using QUIC-Fire, an ensemble of simulations were executed for grassland fires, southeast U.S. conifer forests, and western mountain conifer forests. Resulting emission factors from this ensemble were compared against field data for these fire classes with promising results. Also shown is a predicted averaged resulting particle size distribution with the bulk of particles produced to be on the order of 1 μm in size.

Effects of Disturbance on Understory Vegetation across Slovenian Forest Ecosystems

The herbaceous understory represents a key component of forest biodiversity across temperate forests of Europe. Here, we quantified changes in the diversity and composition of the forest understory layer in representative Slovenian forest ecosystems between 2004/05 and 2014/15. In total, 60 plots were placed across 10 different managed forest types, ranging from lowland deciduous and mid-altitude mesic mixed forests to mountain conifer forests. This network is part of an international network of sites launched within the ICP Forests Programme aimed to assess the condition of forests in Europe. To examine how disturbance influenced understory dynamics, we estimated the disturbance impacts considering both natural and/or anthropogenic disturbances that cause significant damage to trees and to ground-surface layers, including ground-vegetation layers and upper-soil layers. Species richness across 10 sites (gamma diversity) significantly decreased from 272 to 243 species during the study period, while mean species richness per site did not significantly change. The mean value of site level Shannon diversity indices and evenness significantly increased. The cover of most common plant species increased during the monitoring period. The mean value of disturbance estimates per site increased from 0.8% in 2004/05 (ranging from 0% to 2.5%) to 16.3% in 2014/15 (ranging from 5.0% to 38.8%), which corresponded to a reduction in total vegetation cover, including tree-layer cover. More disturbed sites showed larger temporal changes in species composition compared to less disturbed sites, suggesting that forest disturbances caused understory compositional shifts during the study period. Rather than observing an increase in plant diversity due to disturbance, our results suggest a short-term decrease in species number, likely driven by replacement of more specialized species with common species.

Regeneration of Scots pine Pinus sylvestris L. in the Carpathians depends on site fertility

Abstract The aim of this work was to determine the biometric features of Scots pine Pinus sylvestris L. regeneration in terms of their susceptibility to weather-inflicted damage. We compared the damage between three sites located in the Polish part of the Carpathians: Scots pine planted in (I) fertile sites of mountain broadleaved and mixed broadleaved forest, (II) poor sites of mountain coniferous forest and (III) sites of Scots pine natural refuges during the post-glacial period. In each of the three sites of pine regeneration, 11 research plots were established with 50 pine trees on each plot. For each tree, the following biometric measurements were taken: diameter at breast height, height, 3-year height increment, crown length and crown width measured along the contour line. The Scots pine regeneration was found to vary in terms of their biometric features depending on the site fertility. In fertile sites, the biometric parameters of the trees increased at a faster rate compared to low-fertility sites causing an increase in their susceptibility to damage by adverse weather conditions such as snow and rime. Therefore, the silvicultural risk in fertile sites is high and thus the introduction of pine for regeneration should be avoided in fertile broadleaved and mixed broadleaved forests even if pine provenances from a mountain origin are to be planted. Furthermore, tending cuts in regeneration should be made frequently, but with moderate intensity so as to avoid excessive reductions in tree density. Intensive cuts, especially in fertile sites, promote the expansion of pine crowns, which further increases the risk of damage.

Forest biomass estimation over three distinct forest types using TanDEM-X InSAR data and simulated GEDI lidar data

The Global Ecosystem Dynamic Investigation (GEDI) mission has been successfully launched to the International Space Station (ISS) on December 5th, 2018. While the sampling pattern of GEDI (8 transects with about 600 m across-track spacing) is sufficient to provide accurate biomass maps at the mission's required gridded resolution of 1 km, it is of significant interest to fuse GEDI data with ancillary, wall-to-wall remote sensing data from other sensors to provide increased accuracy, potentially higher resolution, and to fill gaps caused by track spacing, clumping in the ISS orbital tracks, as well as from clouds. In this paper, we examine the utility of combining simulated GEDI lidar observations with acquisitions from DLR's TerraSAR-X/TanDEM-X (TDX) InSAR mission to improve forest biomass estimation at a moderate resolution of 1 km, and to produce biomass maps at a much finer resolution of one hectare. We statistically characterize uncertainties before and after fusing simulated GEDI observations with TDX data across three different biomes: a temperate mixed deciduous forest, a temperate and mountainous coniferous forest, and a tropical forest. We implement the Random Volume over Ground (RVoG) model to derive canopy heights from TDX, using GEDI observations to parameterize key variables in the model. Our uncertainty framework is based on application of what are known as hybrid and hierarchical model-based inference, which allows for the parametric estimation of the variance of biomass estimation using both sampled and modeled data. We found improved accuracies after applying our fusion methods, with uncertainties at 1 km resolution ranging from 11%–20% across the different study sites of the mean biomass from the use of GEDI data alone, compared to 7%–12% achieved after the fusion. At one hectare resolution, comparison of the fusion-derived biomass with field plots showed uncertainties associated with mean biomass predictions between 11%–27% across sites. Our results suggest that the use of ancillary data that are sensitive to biomass, such as heights from TDX, with observations of ecosystem structure from GEDI, has the potential to both improve accuracies and/or provide finer spatial resolution, than what is achievable through either mission by itself. We further demonstrate that the GEDI data themselves may be used to parameterize models that invert height from TDX, leading to more accurate height maps for use in biomass estimation. Lastly, our results illustrate the benefits of using parametric estimation theory to quantify uncertainties from both sampling and modeling errors that arise in the fusion of multi-modal remote sensing data at various spatial scales.

Egg laying and incubation rhythm of the Chinese Grouse (Tetrastes sewerzowi) at Lianhuashan, Gansu, China

BackgroundIncubating birds must balance the conflict between thermal needs of the developing embryos and their self-maintenance needs for energy. The Chinese Grouse (Tetrastes sewerzowi) lives in high mountain conifer forests and faces energy stress, cold environment, and predation pressure. Females might adjust incubation rhythm to adapt to these constraints.MethodsTwo methods were used to investigate egg laying and incubation pattern of the Chinese Grouse; 25 nests were monitored by data loggers and 12 nests by infrared video cameras.ResultsFemale Chinese Grouses usually laid an egg every 2 days. The incubation period was 28–31 days. Overall incubation constancy for Chinese Grouse was 93%. The females took 5.0 recesses per day and 34% of all 1696 recesses were taken in the crepuscular period. The average recess duration was 20.3 min. Females took more and shorter recesses in the latter part of incubation. The females who allocated more time to foraging had a higher reproductive success.ConclusionsProbably due to its high egg/body mass ratio, the Chinese Grouse has a long laying interval of 49 h. We suggest that, due to energy stress, females have relatively more recesses and they increase the number of recesses as incubation progresses. To compensate for the embryos’ thermal needs, they extend the incubation period and shorten the recess duration in this cold environment.

Phylogenetic diversity patterns in forests of a putative refugial area in Greece: A community level analysis

Patterns of phylogenetic diversity and structure of flora in refugial areas may be very complex due to habitat heterogeneity and legacies of various historical processes. Revealing these patterns can help understand the nature of the refugia. Here we study phylogenetic patterns of the flora in one of the main putative Pleistocene refugia of temperate forest biota in Europe through a community-level analysis for the main types of forests. For this purpose, a database of vegetation plots from deciduous and mountain coniferous forests of northern and central Greece was created. The plots were classified into floristically and ecologically interpretable community types. Faith’s phylogenetic diversity, mean phylogenetic distance and mean nearest taxon distance, as well as their standardized equivalents, were used to characterize the mean phylogenetic diversity and structure of each community type. All analyses were applied both for all the vascular plant taxa and for angiosperm taxa only. We related the measures of phylogenetic diversity and structure to ecological factors and compared them among community types. The 25 identified community types differed in their phylogenetic diversity and structure. The observed patterns were significantly different when old evolutionary lineages, such as gymnosperms and ferns, were taken into account. A random or overdispersed phylogenetic structure was observed for most of the community types, while only two oak-dominated community types were clustered. The highest phylogenetic diversity and a notably high proportion of plots with an overdispersed phylogenetic structure were observed in two mesic ravine forest community types (one of these transitional to beech forests). Phylogenetic metrics correlated with ecological conditions, in particular, overdispersion was more common in shaded, cool and moist forests. The high phylogenetic diversity and overdispersed structure of the two ravine community types can be related to the putative refugial role of these forest habitats.

Post-fire recovery of Abies cephalonica forest communities: the case of Mt Parnitha National Park, Attica, Greece

Abstract: Mountain coniferous forests of Southern Europe seem to be increasingly affected by large fires. Endemic Greek fir (Abies cephalonica) forests were among the most affected ecosystems by the 2007 extreme wildfires in Greece. The aim of this study is to investigate the pattern of post-fire regeneration of fir forest plant communities of Mount Parnitha National Park, in Attica (Greece), after a large wildfire. A network of 8 severely burned sites across the mountain ridge was established in order to monitor natural regeneration of A. cephalonica as well as post-fire floristic composition and species richness. Field campaigns took place in two distinct time periods, one close to the fire event and one 8 to 10 years after. Generalized linear models were used to explore the effects of distance and microhabitat variables on the post-fire regeneration of the Greek fir. Distance from the unburned patches, slope and cover of woody species significantly affected A. cephalonica seedling establishment and hence its natural post-fire regeneration. Floristic composition and plant species richness of the recovering fir communities changed through time. During the initial phase, high species richness was recorded, mainly because of the high contribution of herbaceous species. During the second period, species richness was lower and similar to that recorded in the unburned fir communities. It is during this period when the first seedlings of the Greek fir managed to establish, although their density is rather low to ensure full recovery of the forest.