Find research datasets worth reusing

opencc-by-nc-sa-4.0Dec 2013View details →

Rosa multiflora (Rosaceae) - woody angiosperms - inflorescence - ventral view of flower + perianth

Image of Rosa multiflora (Rosaceae) - woody angiosperms - inflorescence - ventral view of flower + perianth

Fraxinus americana (Oleaceae) - woody angiosperms - twig - winter overall

Image of Fraxinus americana (Oleaceae) - woody angiosperms - twig - winter overall

Fraxinus americana (Oleaceae) - woody angiosperms - bark - of a large tree

Image of Fraxinus americana (Oleaceae) - woody angiosperms - bark - of a large tree

Fraxinus americana (Oleaceae) - woody angiosperms - fruit - immature

Image of Fraxinus americana (Oleaceae) - woody angiosperms - fruit - immature

Fraxinus americana (Oleaceae) - woody angiosperms - fruit - immature

Image of Fraxinus americana (Oleaceae) - woody angiosperms - fruit - immature

Fraxinus americana (Oleaceae) - woody angiosperms - fruit - immature

Image of Fraxinus americana (Oleaceae) - woody angiosperms - fruit - immature

Fraxinus americana (Oleaceae) - woody angiosperms - whole tree (or vine) - general

Image of Fraxinus americana (Oleaceae) - woody angiosperms - whole tree (or vine) - general

Fraxinus americana (Oleaceae) - woody angiosperms - fruit - as borne on the plant

Image of Fraxinus americana (Oleaceae) - woody angiosperms - fruit - as borne on the plant

opencc-zeroMar 2022View details →

Data from: Woody plant secondary chemicals increase in response to abundant deer and arrival of invasive plants in suburban forests

Plants in suburban forests of eastern North America face the dual stressors of high white-tailed deer density and invasion by nonindigenous plants. The combination of chronic deer herbivory and strong competition from invasive plants could alter a plant's stress- and defense-related secondary chemistry, especially for long-lived juvenile trees in the understory, but this has not been studied. We measured foliar total antioxidants, phenolics, and flavonoids in juveniles of two native trees, Fraxinus pennsylvanica (green ash) and Fagus grandifolia (American beech), growing in six forests in the suburban landscape of central New Jersey, USA. The trees grew in experimental plots that had been subject for 2.5 years to factorial treatments of deer access/exclosure X addition/no addition of the nonindigenous invasive grass Microstegium vimineum (Japanese stiltgrass). As other hypothesized drivers of plant secondary chemistry, we also measured non-stiltgrass herb layer cover, light levels, and water availability. Univariate mixed model analysis of the deer and stiltgrass effects and multivariate structural equation modeling (SEM) of all variables showed that both greater stiltgrass cover and greater deer pressure induced antioxidants, phenolics, and flavonoids, with some variation between species. Deer were generally the stronger factor, and stiltgrass effects were most apparent at high stiltgrass density. SEM also revealed that soil dryness directly increased the chemicals; deer had additional positive, but indirect, effects via influence on the soil; in beech PAR positively affected flavonoids; and herb layer cover had no effect. Juvenile trees' chemical defense/stress responses to deer and invasive plants can be protective, but also could have a physiological cost, with negative consequences for recruitment to the canopy. Ecological implications for species and their communities will depend on costs and benefits of stress/defense chemistry in the specific environmental context, particularly with respect to invasive plant competitiveness, extent of invasion, local deer density, and deer browse preferences.

opencc-zeroMay 2022View details →

Data: Drought and fire determine juvenile and adult woody diversity and dominance in a semi-arid African savanna

Aim: To understand how communities of adult and juvenile (seedlings and saplings) woody plants were impacted by fire and the 2014 – 2016 El Niño drought in Kruger National Park, South Africa. Methods: We used a landscape scale fire experiment spanning 2013-2019 in a semi-arid savanna in the central west of Kruger National Park (mean annual precipitation, 543 mm). Adult and juvenile woody species composition were recorded during and after the drought in 40 plots that experienced a mix of no fire, moderate fire and frequent fire treatments. Using multivariate modelling, we related community composition in juvenile and adult woody plants to year of sampling and the experimental fire treatments. Results: Post-drought, there was significant adult woody plant top-kill, especially in dominant species Dichrostachys cinerea (81% reduction in abundance), Acacia nigrescens (30%), and Combretum apiculatum (19%), but no significant change in adult species richness. Two years post-drought, abundance of all juveniles decreased by 35%, and species richness increased in juveniles in both the frequent fire (7%) and no fire treatments (32%). Conclusion: Counter-intuitively, the El Niño drought increased species richness of the woody plant community due to the recruitment of new species as juveniles, a potential lasting impact on diversity, and where different fire regimes were associated with differences in community composition. Drought events in semi-arid savannas could drive temporal dynamics in species richness and composition in previously unrecognised ways.

opencc-zeroMay 2022View details →

GLOWCAD: A global database of woody tissue carbon concentrations/fractions

Woody tissue carbon (C) concentration is a key wood trait necessary for accurately estimating forest C stocks and fluxes, which also varies widely across species and biomes. However, coarse approximations of woody tissue C (e.g., 50%) remain commonplace in forest C estimation and reporting protocols, despite leading to substantial errors in forest C estimates. Here, we describe the Global Woody Tissue Carbon Concentration Database (GLOWCAD): a database containing 3,676 individual records of woody tissue C concentrations from 864 tree species. Woody tissue C concentration data—i.e., the mass of C per unit dry mass—were obtained from live and dead woody tissues from 130 peer-reviewed sources published between 1980-2020. Auxiliary data for each observation include tissue type, as well as decay class and size characteristics for dead wood. In GLOWCAD, 1,242 data points are associated with geographic coordinates, and are therefore presented alongside 46 standardized bioclimatic variables extracted from climate databases. GLOWCAD represents the largest available woody tissue C concentration database, and informs studies on forest C estimation, as well as analyses evaluating the extent, causes, and consequences of inter- and intraspecific variation in wood chemical traits.

opencc-zeroMay 2022View details →

Dataset for: Aboveground carbon stocks, woody and litter productivity along an elevational gradient in the Rwenzori Mountains, Uganda

Montane forests are characterized by high biodiversity, endemism and strong elevational environmental gradients. The latter attribute makes them also suitable as a 'natural laboratory' for studying the effects of environmental parameters on ecosystem functions. To provide better insight into the carbon cycle of Afromontane ecosystems, we used an elevational gradient approach to quantify carbon stocks, woody and litter productivity, and their constraining factors. Twenty plots were established, covering five elevations from Kibale Forest at 1250 m to 3000 m in the Rwenzori Mountains. Results revealed aboveground carbon stocks of between 185.4 ± 48.9 Mg C ha-1 and 70.8 ±18.6 Mg C ha-1 at 1250-1300 m and 2700-3000 m respectively. Aboveground carbon tended to decrease with elevation, but this trend was not significant. This was due to similarities in stem diameter combined with different effects of tree height and stem density. Similarly, woody productivity did not change with elevation, ranging from 8.3 ± 4.1 Mg C ha-1 year-1 to 3.4 ± 1.5 Mg C ha-1 year-1 at 2500-2600 m and 2700-3000 m respectively. However, litter productivity decreased linearly by 0.14 ± 0.04 Mg C ha-1 year-1 per 100 m of elevation increase, ranging from 4.0 ± 0.7 Mg C ha-1 year-1 at 1750-1850 m to 1.2 Mg C ha-1 year-1 at 2700-3000 m. Topsoil physicochemical properties varied with elevation, but showed no significant relationship with carbon stocks and woody productivity. However, litter productivity increased with mean soil temperature, whereas it decreased with soil total nitrogen.

opencc-by-4.0May 2022View details →

Climate change threatens the distribution of major woody species and ecosystem services provision in southern Africa

Species occurrence points used in this study to investigate the effect of climate change on the distribution of eight tree species in 18 countries in southern Africa, covering 36% of the continent. We proposed a loser/winner ranking of the species based on the changes in climatic suitability within their historical distributions as well as future gains and losses of suitable areas. We interpreted these findings in terms of changes in the provision of key ES (timber, food, energy, and medicine), and identified hotspots of ES provision decline. We used species presence data from the Global Biodiversity Information Facility, climatic data from the AfriClim dataset, and the MaXent algorithm to project the changes in species' land suitability.

opencc-zeroJun 2022View details →

Cross-scale drivers of woody plant species commonness and rarity in the Brazilian drylands

Aim: Locally abundant species are typically widespread, while locally scarce species are geographically restricted – the so-called abundance-occupancy relationships (AORs). AORs help explain the drivers of species rarity and community assembly, but little is known about how variation around such relationships is driven by species traits and niche-based processes, particularly in tropical woody plants. We tested the hypothesis that AORs in tropical dryland woody plants are positive and mediated by niche and functional traits along environmental gradients. Location: The Caatinga dry forest and Cerrado savannah, Brazil. Methods: We aggregated abundance and occurrence data into grid-cells representing local (10-km) to landscape scales (50-km). We calculated species mean relative abundance at occupied grid-cells (local abundance) and the proportion of grid-cells occupied (occupancy), and estimated their niche breadth and marginality along multivariate environmental gradients. Results: AORs were positive but weak at different scales in both regions due to some locally abundant but geographically restricted species, with most species being both locally and geographically rare. Cross-species variation in local abundance was largely unpredictable, but occupancy was strongly driven by niche and functional traits, with a prominent negative effect of niche marginality. Geographically restricted species were associated with rare habitats, such as wetter and less intensively used habitats. Large seeds and abiotic dispersal favoured occupancy in Caatinga at small and large spatial scales, respectively, whereas species with conservative leaves were more widespread across scales in Cerrado. Main conclusions: Woody plants in dry tropical biotas exhibit weak AORs, likely related to low habitat availability and dispersal limitation. Caatinga and Cerrado emerge as environmentally structured at multiple spatial scales, with several habitat-specialist rare species bearing specific regenerative and resource-use traits and relying on conditions threatened by climate change and land-use intensification. Examining AORs through the lens of niche, functional traits and spatial scales enables mapping patterns and drivers of species commonness and rarity, enhancing understanding of species assembly and providing tools for biodiversity conservation.

opencc-by-4.0Jul 2022View details →

Age and phenology control photosynthesis and leaf traits in the understory woody species, Rhamnus cathartica and Prunus serotina

Dataset contains leaf physiological variables and leaf traits from Rhamnus cathartica (buckthorn) and Prunus serotina (Black cherry) measured in Summer 2019 at Macalester College's Ordway Field Station. All data were collected on understory individuals from 4 sites within the forest in late May and early July, 2019. We sampled from 'tree' individuals and seedlings of both species. All methods and measurement protocols are published in Heskel et al. 2022 in AoB-PLANTS, currently in revision. Data includes:  Vcmax (umol m2-s-1) Jmax (umol m2-s-1) Fv/Fm (no units) Leaf Stomatal Density (stomata mm-2) Dark respiration (umol m2-s-1) Asat (umol m2-s-1) A400 (umol m2-s-1) Carbon Gain Efficiency (CGE, no units) CGE_400 (CGE at 400 PAR, no units) Leaf Mass per Are (LMA, g m-2)

opencc-zeroJul 2022View details →

Data From: Evolution of woody plants to the land‐sea interface: The atypical genomic features of mangroves with atypical phenotypic adaptation

How plants adapt and diverge in extreme environments is a key question of plant evolution and ecology. Mangrove invasion of intertidal environments is facilitated by adaptive phenotypes such as aerial roots, salt-secreting leaf, and viviparity, and genomic mechanisms including whole genome duplication and transposable element number reduction. However, a number of mangroves lack these typical phenotypes. The question we ask is whether these phenotypically atypical mangroves also have distinct genomic features? The sibling mangrove species Lumnitzera littorea and Lumnitzera racemosa provide a model to study this question. We sequenced and assembled their genomes to chromosome level, together with a closely related species Combretum micranthum. While most mangroves have small genomes, the genomes of both Lumnitzera species are large (1443 and 1317 Mb) and carry a high proportion of repeat sequences (~75%). Moreover, Lumnitzera species have not undergone post-gamma whole-genome duplications. Their genome size increased mainly due to the expansion of repeat sequences in their ancestors. However, Lumnitzera genomes have reduced transposable elements by constraining the proliferation of new LTR-RTs. Meanwhile, the two species have more gene families contracted than expanded, and some gene families with reversed size change may underlie their differentiation in root morphology and local distribution. We identified 86 chromosomal inversions, five of which are measured between 6.5 and 12.8 megabases. A number of genes located in these inversions function in pigment biosynthesis, a process likely involved in flower color differentiation between the Lumnitzera species. We conclude that the mangroves with atypical phenotypes also have atypical genomic evolution.

opencc-zeroJul 2022View details →

Data from: Climate warming leads to advanced fruit development period of temperate woody species but divergent changes in its length

Climate warming has significantly altered the phenology of plants in recent decades. However, in contrast to the widely reported warming-induced extension of vegetative growing season, the response of fruit development period (FDP) from flowering to fruiting remains largely unexplored, particularly for woody plants. Analyzing >560,000 in situ observations of both flowering and fruiting dates for six temperate woody species across 2958 European phenological observations sites during 1980 – 2013, we found that in all species both flowering and fruiting phenology, i.e., the FDP, advanced with climate warming. However, the advancing rates of the two events were not necessarily equal for any given species, resulting in divergent changes in the length of FDP among species with climate warming. During 1980 – 2013, not only the temperature during FDP but also the forcing requirement for fruit development increased, both affecting the length of FDP. The shortened FDP was mainly due to elevated temperature, thus accelerating the accumulation of forcing, whereas the prolonged FDP was primarily caused by the substantial increase of the forcing requirement of fruiting, which could be fulfilled only in a longer time and thus slowed down the advance of fruiting. This study provides large-scale empirical evidence of warming-induced advances of FDP but divergent changes in its length in temperate woody species. Our findings demonstrate the contrasting reproductive phenological strategies among temperate woody species under the pressure of warming climate, contrary to the lengthening of vegetative growing season, which is by and largely similar with different woody species.

opencc-by-4.0Jul 2022View details →

Data from: Integrating herbivore assemblages and woody plant cover in an African savanna to reveal how herbivores respond to ecosystem management

African savannas are experiencing anthropogenically-induced stressors that are accelerating the increase of woody vegetation cover. To combat this, land managers frequently implement large-scale clearing of trees, which can have a cascading influence on mammalian herbivores. Studies rarely focus on how differences in woody cover influence the herbivore assemblage, making it difficult to assess how aggressive measures, or the lack of management, to counteract increasing woody cover affect the local composition and biodiversity of herbivores. We address this knowledge gap by applying a model-based clustering approach to field observations from to identify multiple herbivore–vegetation ‘configurations,’ defined as unique sets of herbivore assemblages (i.e., groups of herbivores) associated with differing woody plant covers. Our approach delineated how tree-clearing influences the distribution and abundance of the herbivore community in relation to surrounding savanna areas, which represent a natural mosaic of varying woody cover. Regardless of season, both intensively managed areas cleared of trees and unmanaged areas with high tree cover contained configurations that had depauperate assemblages of herbivores (low species richness, low abundance). By contrast, habitats with intermediate cover of woody vegetation had much higher richness and abundance. These results have substantial implications for managing African savannas in a rapidly changing climate.

openJun 2022View details →

Terrestrial laser scanner (TLS) and destructive measurements in short-rotation woody crops (SRWCs) in NE of Romania

The data are obtained from hybrid poplar crops installed in NE Romania, managed in short rotation (SRWCs) between 5, 6, and 7 growing seasons. Planted every spring, outside the growing season, at a depth of 0.6 m in the ground with two clones: AF8 and Pannonia. Rods (2 m long cuttings) were used as planting material for a density of 1667 trees/ha (3 x 2 m). For the estimation of volume and biomass, scans and gravimetric measurements were performed on tree component parts (trunk/stem and branches). Scanning of the sample areas (3 x 10 trees for each variant) was carried out using the Z+F Imager 5010. The scanning period was outside the growing seasons. The destructive (gravimetric) method of estimating biomass involves weighing the trees (184 in total) by component parts: trunk and branches (10 g accuracy). The moisture content of the components was determined by drying the samples (wood discs and branches) at a temperature of 105 °C to a constant mass. The QSM Model in MatLab was used for tree volume reconstruction. Where d is the diameter (cm) - measured at the base and at 1 m height, h (m) is the total height - measured after harvesting by roulette and by QSM reconstruction (after TLS scan). B (kg) is the dry mass of the whole tree (tot = branches + stem) and stem, and V (litres/ dm3) is the tree volume (tot) for the whole tree and stem. Branch weight results by difference for both variables.