Community succession in an urban novel forest after four decades of regeneration

This study aimed to analyse the tree community of an urban forest with 40 years of natural regeneration after abandonment of the degraded land. We hypothesized that after four decades of forest succession, the diversity, structure and functional aspects of the community would be similar to other secondary surrounding forests. We established ten plots (20x 20m), where all trees with DBH ≥ 5 cm were sampled. The inventory included 605 trees (1513 ind.ha-1 ) distributed across 25 species. The diversity index (H’ = 0.92) and basal area (10.43 m2.ha-1) were lower than in surrounding forests. The results showed a great dominance of Eremanthus erythropappus with consequent delay in successional advance, and low potential of attraction of fauna, which suggests the need for management to control its population. Understanding the functioning of novel urban forests and discussing these neglected ecosystems is fundamental to guide management actions for both human and ecosystem prosperity.

Data from Raymundo et al. (2018)

1- Soil_moisture: Soil moisture of plots close (0) and far (10) from water's edge, in dry (D) and rainy (R) season, before and after the reservoir construction in two tropical dry forests in Brazil. Transects and Slope (degrees) are given. 2- Net_changes: Forest structure, species and functional diversity metrics and community weighted mean (CMW) per plot in t0 and t10 of two patches of tropical dry forests. Transects (Trans.); Distance (Distance); Longitude (x.); Latitude (y); Number of individuals (NI); basal area (BA); species richness (S); rarefied species richness (Srar); functional richness (Fric); Functional dispersion (Fdis); and community weighted mean of specific leaf area (SLA), wood density (WD), deciduousness (Dec) and compound leaves (Comp). Plot distance to the water edge (m), transects and Slope (degrees) are given. 3- Demographic groups: Forest structure, species and functional diversity metrics and community weighted mean (CMW) per plot of Recruits (R), Dead trees (D) and survivors (S) in two patches of tropical dry forests. Longitude (x.); Latitude (y); Number of individuals (NI); basal area (BA); species richness (S); rarefied species richness (Srar); functional richness (Fric); Functional dispersion (Fdis); and community weighted mean of specific leaf area (SLA), wood density (WD), deciduousness (Dec) and compound leaves (Comp). Plot distance to the water edge (m), transects and Slope (degrees) are given

Functional traits shape size-dependent growth and mortality rates of dry forest tree species

Aims: Functional traits have emerged as an important tool to evaluate plant performance. However, the environmental conditions and ecological pressures that plants face change with their size, and the relationship between traits and plant performance should therefore be size-dependent, which has rarely been tested. Methods: Here, we evaluated over a broad range of tree sizes the interspecific relationship between tree growth and mortality and eight functional stem, leaf and seed traits. We did so across 59 tree species in Brazilian dry forests and evaluated whether the relationships found for wet forest types in the literature also hold for dry forests, where water rather than light might limit tree performance. Important Findings: We indeed found a strong size-dependent relationship between demographic rates and functional traits. At small sizes, when trees are in the shaded understory, species with functional trait values that enhance light capture or shade tolerance (i.e. higher maximum adult stature, taller heights, wider crowns, higher seed mass) have higher growth and/or lower mortality rates (MR). This relationship disappears at larger sizes when trees attain better light conditions in the canopy. Drought adaptations play only a role at larger tree sizes; once trees are in the dry and exposed canopy, species with higher wood density (an indicator of cavitation resistance) have lower MRs. Our study shows that both drought and shade adaptations are important in this dry forest, and that the relationships between functional traits and plant performance changes with plant size. Plant size should therefore explicitly be included as an axis of variation in functional analyses, to better understand the relationship between functional traits and demographic rates

Data from: Conservative species drive biomass productivity in tropical dry forests

Data of above-ground biomass dynamics over a five-year period in eight seasonal tropical dry forests in Minas Gerais state, Southeastern Brazil. In each forest, 25 permanent sample plots (20 × 20 m) were established totaling one ha per site. Biomass dynamics, structural, floristic, functional and soil variables used in the biomass models are given. AGBi = stand biomass, AGBnet = net biomass change, AGBsurv = biomass growth of surviving trees, AGBmort = biomass mortality, AGBrecr = biomass recruitment, NI = tree-density (ha-1), CWM = community weighed mean, WD = wood density, Dmax = maximum stem diameter, SLA = specific leaf area, Dec = deciduousness, S = rarefied species richness, H’ = Shannon-Wiener index, J’ = Pielou’s index, Fric = functional richness, Feve = functional evenness, Fdiv = functional divergence, P = phosphorous, K = potassium, Ca = calcium, Mg = magnesium, Al = aluminum, CEC = cation exchange capacity

Data from: Shifting species and functional diversity due to abrupt changes in water availability in tropical dry forests

Recent insights show that tropical forests are shifting in species composition, possibly due to changing environmental conditions. However, we still poorly understand the forest response to different environmental change drivers, which limits our ability to predict the future of tropical forests. Although some studies have evaluated drought effects on tree communities, we know little about the influence of increased water availability. Here, we evaluated how an increase in water availability caused by an artificial reservoir affected temporal changes in forest structure, species and functional diversity, and community‐weighted mean traits. Furthermore, we evaluated how demographical groups (recruits, survivors and trees that died) contributed to these temporal changes in tropical dry forests. We present data for the dynamics of forest change over a 10‐year period for 120 permanent plots that were far from the water’s edge before reservoir construction and are now close to the water’s edge (0–60 m). Plots close to the water’s edge had an abrupt increase in water availability, while distant plots did not. Plots close to the water’s edge showed an increase in species and functional diversity, and in the abundance of species with traits associated with low drought resistance (i.e., evergreen species with simple leaves and low wood density), whereas plots far from the water’s edge did not change. Changes in overall community metrics were mainly due to recruits rather than to survivors or dead trees. Overall stand basal area did not change because growth and recruitment were balanced by mortality. Synthesis. Our results showed that tropical dry forests can respond quickly to abrupt changes in environmental conditions. Temporal changes in vegetation metrics due to increased water availability were mainly attributed to recruits, suggesting that these effects are lasting and may become stronger over time. The lack of increase in basal area towards the water’s edge, and the shift towards higher abundance of soft‐wooded species, could reduce the carbon stored and increase the forest’s vulnerability to extreme weather events. Further “accidental” large‐scale field experiments like ours could provide more insights into forest responses and resilience to global change

Community Succession in an Urban Novel Forest after Four Decades of Regeneration

ABSTRACT This study aimed to analyse the tree community of an urban forest with 40 years of natural regeneration after abandonment of the degraded land. We hypothesized that after four decades of forest succession, the diversity, structure and functional aspects of the community would be similar to other secondary surrounding forests. We established ten plots (20x 20m), where all trees with DBH ≥ 5 cm were sampled. The inventory included 605 trees (1513 ind.ha-1 ) distributed across 25 species. The diversity index (H’ = 0.92) and basal area (10.43 m2.ha-1) were lower than in surrounding forests. The results showed a great dominance of Eremanthus erythropappus with consequent delay in successional advance, and low potential of attraction of fauna, which suggests the need for management to control its population. Understanding the functioning of novel urban forests and discussing these neglected ecosystems is fundamental to guide management actions for both human and ecosystem prosperity

Conservative species drive biomass productivity in tropical dry forests

<p>Forests account for a substantial part of the terrestrial biomass storage and productivity. To better understand forest productivity, we need to disentangle the processes underlying net biomass change. We tested how above-ground net biomass change and its underlying biomass dynamics (biomass recruitment, growth and mortality) can be explained by four alternative and contested hypotheses; the soil fertility, biomass ratio, niche complementarity and vegetation quantity hypotheses. Above-ground biomass dynamics were evaluated over a 5-year period in 200 permanent sample plots in 8 tropical dry forests in Brazil, and related to soil fertility, community-weighted mean (CWM) traits that are important for carbon storage and sequestration (wood density, specific leaf area, maximum stem diameter and deciduousness), species richness, functional diversity and initial stand biomass. Initial stand biomass was the best predictor of all three processes of biomass dynamics, providing strong support for the vegetation quantity hypothesis. In these dry forests, the dominance of conservative species, rather than of acquisitive species, is associated with high biomass growth and storage, probably because their low specific leaf area and high wood density allow them to keep on functioning during drought stress. Paradoxically, high soil fertility (Ca) led to low biomass productivity, probably because of nutrient imbalance. In contrast to what is shown for controlled experiments, we found no support for niche complementarity (in terms of functional diversity or species richness) for forest productivity. Biomass storage was favoured by low- rather than high trait diversity, as most of the biomass is concentrated in species with large stem diameter and high wood density. Synthesis. Biomass dynamics are mainly shaped by vegetation quantity, and then by vegetation quality, in line with the mass ratio hypothesis. Dry forests show different trait-productivity relationships than wet forests, as stands with 'slow' trait values are 'fast' in terms of productivity. Diversity matters, but in a different way than expected; high trait diversity does not enhance productivity, but instead, does low trait diversity enhance carbon storage. Biomass dynamics are mainly shaped by vegetation quantity, and then by vegetation quality, in line with the mass ratio hypothesis. Dry forests show different trait-productivity relationships than wet forests, as stands with 'slow' trait values are 'fast' in terms of productivity. Diversity matters, but in a different way than expected; high trait diversity does not enhance productivity, but instead, does low trait diversity enhance carbon storage.</p

Damming water influences the structure, composition and functions of adjacent savannahs

Dams are important to human wellbeing; however, they can cause various environmental changes. In the cerrado stricto sensu, waters from the reservoir modify water supply in the soil and can affect species establishment. It is argued that species adapted to high water availability can establish close to river banks and water reservoirs and their characteristics are different from those of species from the cerrado stricto sensu. These characteristics could be more similar to those of species from riparian forests, with higher values of height and basal area. Thus, we aim to analyze changes in an area of the cerrado stricto sensu, 35 years after the construction of a hydroelectric dam. We tested different parameters to determine these changes, including richness, diversity, individual height and basal area (using the square-point method), with individuals 1 m, and Bromeliaceae (using the plot method) in three sectors close to the artificial lakeshore (0 m - 20 m, 40 m - 60 m, and 80 m - 100 m away from the water). Using species diversity, we also compared the species functional group within these sectors. Sectors closer to the dam acted as an edge, presenting lower basal area and individual’s height, but species with different traits compared to those of a cerrado stricto sensu area.Represas são importantes para o bem-estar humano, no entanto, podem causar diversas alterações nos ambientes. No cerrado stricto sensu, as águas represadas modificam o abastecimento de água no solo e podem alterar o estabelecimento das espécies. Argumenta-se que as espécies adaptadas à alta disponibilidade de água podem estabelecer-se próximo às margens de rios e reservatórios e possuem características distintas daquelas de espécies de cerrado stricto sensu. As características seriam mais semelhantes àquelas de espécies de matas ciliares, com elevada estatura e área basal. Assim, almejamos analisar as mudanças em uma área de cerrado stricto sensu após 35 anos sob a influência de uma usina hidrelétrica. Testamos parâmetros distintos para determinar essas mudanças, tais como a riqueza, a diversidade, altura dos indivíduos e área basal (utilizando o método do ponto quadrante), com indivíduos 1 m e Bromeliaceae (utilizando o método de parcelas) em três setores próximo à margem da represa (a 0 m - 20 m, 40 m - 60 m e 80 m - 100 m da represa). Utilizando a diversidade de espécies, também comparamos os grupos funcionais de espécies nesses setores. Os setores mais próximos à represa possuíam baixa área basal e altura dos indivíduos atuando como uma borda, mas com espécies com diferentes características em relação ao cerrado stricto sensu