Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 171
Filtrar
Mais filtros

Intervalo de ano de publicação
1.
Proc Natl Acad Sci U S A ; 121(34): e2402970121, 2024 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-39133856

RESUMO

Ecosystem restoration is inherently a complex activity with inevitable tradeoffs in environmental and societal outcomes. These tradeoffs can potentially be large when policies and practices are focused on single outcomes versus joint achievement of multiple outcomes. Few studies have assessed the tradeoffs in Nature's Contributions to People (NCP) and the distributional equity of NCP from forest restoration strategies. Here, we optimized a defined forest restoration area across India with systematic conservation planning to assess the tradeoffs between three NCP: i) climate change mitigation NCP, ii) biodiversity value NCP (habitat created for forest-dependent mammals), and iii) societal NCP (human direct use of restored forests for livelihoods, housing construction material, and energy). We show that restoration plans aimed at a single-NCP tend not to deliver other NCP outcomes efficiently. In contrast, integrated spatial forest restoration plans aimed at achievement of multiple outcomes deliver on average 83.3% (43.2 to 100%) of climate change mitigation NCP, 89.9% (63.8 to 100%) of biodiversity value NCP, and 93.9% (64.5 to 100%) of societal NCP delivered by single-objective plans. Integrated plans deliver NCP more evenly across the restoration area when compared to other plans that identify certain regions such as the Western Ghats and north-eastern India. Last, 38 to 41% of the people impacted by integrated spatial plans belong to socioeconomically disadvantaged groups, greater than their overall representation in India's population. Moving ahead, effective policy design and evaluation integrating ecosystem protection and restoration strategies can benefit from the blueprint we provide in this study for India.


Assuntos
Biodiversidade , Mudança Climática , Conservação dos Recursos Naturais , Florestas , Conservação dos Recursos Naturais/métodos , Humanos , Índia , Ecossistema , Recuperação e Remediação Ambiental/métodos
2.
Proc Natl Acad Sci U S A ; 121(7): e2306775121, 2024 Feb 13.
Artigo em Inglês | MEDLINE | ID: mdl-38315850

RESUMO

Limiting global warming to 2 °C requires urgent action on land-based mitigation. This study evaluates the biogeochemical and biogeophysical implications of two alternative land-based mitigation scenarios that aim to achieve the same radiative forcing. One scenario is primarily driven by bioenergy expansion (SSP226Lu-BIOCROP), while the other involves re/afforestation (SSP126Lu-REFOREST). We find that overall, SSP126Lu-REFOREST is a more efficient strategy for removing CO2 from the atmosphere by 2100, resulting in a net carbon sink of 242 ~ 483 PgC with smaller uncertainties compared to SSP226Lu-BIOCROP, which exhibits a wider range of -78 ~ 621 PgC. However, SSP126Lu-REFOREST leads to a relatively warmer planetary climate than SSP226Lu-BIOCROP, and this relative warming can be intensified in certain re/afforested regions where local climates are not favorable for tree growth. Despite the cooling effect on a global scale, SSP226Lu-BIOCROP reshuffles regional warming hotspots, amplifying summer temperatures in vulnerable tropical regions such as Central Africa and Southeast Asia. Our findings highlight the need for strategic land use planning to identify suitable regions for re/afforestation and bioenergy expansion, thereby improving the likelihood of achieving the intended climate mitigation outcomes.

3.
Proc Natl Acad Sci U S A ; 120(23): e2221840120, 2023 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-37252998

RESUMO

Afforestation and reforestation (AR) on marginal land are nature-based solutions to climate change. There is a gap in understanding the climate mitigation potential of protection and commercial AR with different combinations of forest plantation management and wood utilization pathways. Here, we fill the gap using a dynamic, multiscale life cycle assessment to estimate one-century greenhouse gas (GHG) mitigation delivered by (both traditional and innovative) commercial and protection AR with different planting density and thinning regimes on marginal land in the southeastern United States. We found that innovative commercial AR generally mitigates more GHGs across 100 y (3.73 to 4.15 Giga tonnes of CO2 equivalent (Gt CO2e)) through cross-laminated timber (CLT) and biochar than protection AR (3.35 to 3.69 Gt CO2e) and commercial AR with traditional lumber production (3.17 to 3.51 Gt CO2e), especially in moderately cooler and dryer regions in this study with higher forest carbon yield, soil clay content, and CLT substitution. In a shorter timeframe (≤50 y), protection AR is likely to deliver higher GHG mitigation. On average, for the same wood product, low-density plantations without thinning and high-density plantations with thinning mitigate more life cycle GHGs and result in higher carbon stock than that of low-density with thinning plantations. Commercial AR increases the carbon stock of standing plantations, wood products, and biochar, but the increases have uneven spatial distributions. Georgia (0.38 Gt C), Alabama (0.28 Gt C), and North Carolina (0.13 Gt C) have the largest carbon stock increases that can be prioritized for innovative commercial AR projects on marginal land.


Assuntos
Gases de Efeito Estufa , Madeira , Madeira/metabolismo , Agricultura Florestal , Solo , Carbono/metabolismo , Georgia
4.
Planta ; 260(1): 31, 2024 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-38888604

RESUMO

Deforestation of Atlantic Forest has caused prolonged drought events in the last decades. The need for reforestation is growing, and the development of native seedlings that are more tolerant to drought stress is necessary. A biotechnological tool that improves plant tolerance is the use of plant growth-promoting bacteria (PGPB) as inoculants. Two species of PGPB were inoculated in drought-stressed seedlings of two neotropical tree species that have been used in environmental restoration programs: Cecropia pachystachya and Cariniana estrellensis. Biometrical, physiological, and metabolomic parameters from carbon and nitrogen pathways were evaluated. We found that the PGPB positively influenced photosynthesis and growth parameters in both trees under drought. The enzymes activities, the tricarboxylic acid cycle intermediates, the amino acids, and protein contents were also influenced by the PGPB treatments. The results allowed us to find the specific composition of secondary metabolites of each plant species. This study provides evidence that there is not a single mechanism involved in drought tolerance and that the inoculation with PGPB promotes a broad-spectrum tolerance response in Neotropical trees. The inoculation with PGPB appears as an important strategy to improve drought tolerance in Atlantic Forest native trees and enhance environmental restoration programs' success. MAIN CONCLUSION: The association with plant growth-promoting bacteria improved the tolerance to drought in Neotropical trees through biochemical, physiological, and biometrical parameters. This can enhance the success of forest restoration programs.


Assuntos
Carbono , Secas , Metabolômica , Nitrogênio , Folhas de Planta , Árvores , Carbono/metabolismo , Nitrogênio/metabolismo , Folhas de Planta/metabolismo , Folhas de Planta/microbiologia , Árvores/microbiologia , Árvores/metabolismo , Árvores/fisiologia , Cecropia/metabolismo , Cecropia/fisiologia , Fotossíntese , Estresse Fisiológico , Bactérias/metabolismo , Plântula/microbiologia , Plântula/crescimento & desenvolvimento , Plântula/fisiologia , Plântula/metabolismo
5.
Glob Chang Biol ; 30(1): e17077, 2024 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-38273583

RESUMO

Deforestation of tropical rainforests is a major land use change that alters terrestrial biogeochemical cycling at local to global scales. Deforestation and subsequent reforestation are likely to impact soil phosphorus (P) cycling, which in P-limited ecosystems such as the Amazon basin has implications for long-term productivity. We used a 100-year replicated observational chronosequence of primary forest conversion to pasture, as well as a 13-year-old secondary forest, to test land use change and duration effects on soil P dynamics in the Amazon basin. By combining sequential extraction and P K-edge X-ray absorption near edge structure (XANES) spectroscopy with soil phosphatase activity assays, we assessed pools and process rates of P cycling in surface soils (0-10 cm depth). Deforestation caused increases in total P (135-398 mg kg-1 ), total organic P (Po ) (19-168 mg kg-1 ), and total inorganic P (Pi ) (30-113 mg kg-1 ) fractions in surface soils with pasture age, with concomitant increases in Pi fractions corroborated by sequential fractionation and XANES spectroscopy. Soil non-labile Po (10-148 mg kg-1 ) increased disproportionately compared to labile Po (from 4-5 to 7-13 mg kg-1 ). Soil phosphomonoesterase and phosphodiesterase binding affinity (Km ) decreased while the specificity constant (Ka ) increased by 83%-159% in 39-100y pastures. Soil P pools and process rates reverted to magnitudes similar to primary forests within 13 years of pasture abandonment. However, the relatively short but representative pre-abandonment pasture duration of our secondary forest may not have entailed significant deforestation effects on soil P cycling, highlighting the need to consider both pasture duration and reforestation age in evaluations of Amazon land use legacies. Although the space-for-time substitution design can entail variation in the initial soil P pools due to atmospheric P deposition, soil properties, and/or primary forest growth, the trend of P pools and process rates with pasture age still provides valuable insights.


Assuntos
Floresta Úmida , Solo , Solo/química , Fósforo , Ecossistema , Conservação dos Recursos Naturais , Florestas
6.
Glob Chang Biol ; 30(2): e17195, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-38389196

RESUMO

Scientific innovation is overturning conventional paradigms of forest, water, and energy cycle interactions. This has implications for our understanding of the principal causal pathways by which tree, forest, and vegetation cover (TFVC) influence local and global warming/cooling. Many identify surface albedo and carbon sequestration as the principal causal pathways by which TFVC affects global warming/cooling. Moving toward the outer latitudes, in particular, where snow cover is more important, surface albedo effects are perceived to overpower carbon sequestration. By raising surface albedo, deforestation is thus predicted to lead to surface cooling, while increasing forest cover is assumed to result in warming. Observational data, however, generally support the opposite conclusion, suggesting surface albedo is poorly understood. Most accept that surface temperatures are influenced by the interplay of surface albedo, incoming shortwave (SW) radiation, and the partitioning of the remaining, post-albedo, SW radiation into latent and sensible heat. However, the extent to which the avoidance of sensible heat formation is first and foremost mediated by the presence (absence) of water and TFVC is not well understood. TFVC both mediates the availability of water on the land surface and drives the potential for latent heat production (evapotranspiration, ET). While latent heat is more directly linked to local than global cooling/warming, it is driven by photosynthesis and carbon sequestration and powers additional cloud formation and top-of-cloud reflectivity, both of which drive global cooling. TFVC loss reduces water storage, precipitation recycling, and downwind rainfall potential, thus driving the reduction of both ET (latent heat) and cloud formation. By reducing latent heat, cloud formation, and precipitation, deforestation thus powers warming (sensible heat formation), which further diminishes TFVC growth (carbon sequestration). Large-scale tree and forest restoration could, therefore, contribute significantly to both global and surface temperature cooling through the principal causal pathways of carbon sequestration and cloud formation.


Assuntos
Sequestro de Carbono , Mudança Climática , Florestas , Planetas , Temperatura , Água , Temperatura Baixa , Árvores
7.
Ecol Appl ; 34(2): e2947, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38305124

RESUMO

Revegetation plantings are a key activity in farmland restoration and are commonly assumed to support biotic communities that, with time, replicate those of reference habitats. Restoration outcomes, however, can be highly variable and difficult to predict; hence there is value in quantifying restoration success to improve future efforts. We test the expectation that, over time, revegetation will restore bird communities to match those in reference habitats; and assess whether specific planting attributes enhance restoration success. We surveyed birds in 255 sites in south-east Australia, arranged along a restoration gradient encompassing three habitat types: unrestored farmland (paddocks), revegetation plantings (comprising a chronosequence up to 52 years old) and reference habitats (remnant native vegetation). Surveys were undertaken in 2006/2007 and again in 2019, with data used to compare bird assemblages between habitat types. We also determined whether, in the intervening 12 years, bird communities in revegetation had shifted toward reference habitats on the restoration gradient. Our results showed that each habitat contained a unique bird community and that, over time, assemblages in revegetation diverged away from those in unrestored farmland and converged toward those in reference habitats. Two planting attributes influenced this transition: the bird assemblages of revegetation were more likely to have diverged away from those of unrestored farmland (with scattered mature trees) 12 years later if they were located in areas with more surrounding tree cover, and were mostly ungrazed by livestock (compared with grazed plantings). Our results highlight three key ways in which revegetation contributes to farmland restoration: (1) by supporting richer and more diverse bird assemblages than unrestored farmland, (2) by enhancing beta diversity in rural landscapes through the addition of a unique bird community, and (3) by shifting bird assemblages toward those found in reference habitats over time. However, revegetation plantings did not replicate reference habitats by ~40-50 years in our region, and complete convergence may take centuries. These findings have implications for environmental offset programs and mean that effective conservation in farmland environments depends on the retention and protection of natural and seminatural habitats as a parallel management strategy to complement restoration.


Assuntos
Biota , Aves , Animais , Fazendas , Gado , Árvores
8.
Environ Sci Technol ; 2024 Feb 08.
Artigo em Inglês | MEDLINE | ID: mdl-38328901

RESUMO

Deforestation reduces the capacity of the terrestrial biosphere to take up toxic pollutant mercury (Hg) and enhances the release of secondary Hg from soils. The consequences of deforestation for Hg cycling are not currently considered by anthropogenic emission inventories or specifically addressed under the global Minamata Convention on Mercury. Using global Hg modeling constrained by field observations, we estimate that net Hg fluxes to the atmosphere due to deforestation are 217 Mg year-1 (95% confidence interval (CI): 134-1650 Mg year-1) for 2015, approximately 10% of global primary anthropogenic emissions. If deforestation of the Amazon rainforest continues at business-as-usual rates, net Hg emissions from the region will increase by 153 Mg year-1 by 2050 (CI: 97-418 Mg year-1), enhancing the transport and subsequent deposition of Hg to aquatic ecosystems. Substantial Hg emissions reductions are found for two potential cases of land use policies: conservation of the Amazon rainforest (92 Mg year-1, 95% CI: 59-234 Mg year-1) and global reforestation (98 Mg year-1, 95% CI: 64-449 Mg year-1). We conclude that deforestation-related emissions should be incorporated as an anthropogenic source in Hg inventories and that land use policy could be leveraged to address global Hg pollution.

9.
Am J Primatol ; 86(3): e23483, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-36851838

RESUMO

The northeast of Madagascar is as diverse as it is threatened. The area bordering the Analanjirofo and SAVA regions contains six protected areas and at least 22 lemur species. Many applied research and conservation programs have been established in the region with the aim of ensuring both wildlife and people thrive in the long term. While most of the remaining humid evergreen forest of northeast Madagascar is formally protected, the local human population depends heavily on the land, and unsustainable natural resource use threatens this biodiversity hotspot. Drawing from our collective experiences managing conservation activities and research programs in northeast Madagascar, we discuss the major threats to the region and advocate for eight conservation activities that help reduce threats and protect the environment, providing specific examples from our own programs. These include (1) empowering local conservation actors, (2) ensuring effectively protected habitat, (3) expanding reforestation, (4) establishing and continuing long-term research and monitoring, (5) reducing food insecurity, (6) supporting environmental education, (7) promoting sustainable livelihoods, and (8) expanding community health initiatives. Lastly, we provide a list of actions that individuals can take to join us in supporting and promoting lemur conservation.


Assuntos
Lemur , Lemuridae , Humanos , Animais , Madagáscar , Conservação dos Recursos Naturais , Ecossistema , Biodiversidade
10.
Int J Phytoremediation ; 26(5): 784-792, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-37846073

RESUMO

In semi-arid regions, is necessary to explore strategies to mitigate abiotic stresses such as water deficit and salinity. This study aimed to evaluate the stress tolerance capacity of three species subjected to different water regimes and salinity levels, based on dry matter production and water use efficiency (WUE). The species Handroanthus impetiginosus, Vachellia farnesiana, and Amburana cearensis were evaluated in combination with different water regimes (50%, 75%, and 100% of reference evapotranspiration - ET0) and salinity levels (0.18, 1.50, and 1.90 dS m-1). The results show that biomass accumulation increased at 50% and 75% ET0, while the WUE decreased at 100% ET0. The salinity level (1.90 dS m-1) caused reductions in leaf dry biomass (LDB), total dry biomass (TDB), LDB/TDB ratio, and WUE. The negative effects of high salinity on plant height were greater with the application of 75% ET0. The highest WUE was obtained at 50% ET0 for A. cearensis and H. impetiginosus, while V. farnesiana obtained the highest WUE at 75% ET0. A. cearensis exhibited the highest biomass accumulation (2.58 g) and WUE (0.21 g L-1). Overall, the species can tolerate drought and salinity conditions, being sensitive to high salinity concentrations during their initial growth.


The Caatinga is characterized by low water availability and soil salinization. Therefore, assessing the ability of native species to cope with these conditions allows for their utilization in reforestation programs in drought and salinity-exposed environments. Studies on the combined effects of these factors are scarce. The results indicated that native species show tolerance to drought and salinity conditions, albeit with some reductions in biomass production and water use efficiency at high NaCl concentrations. Among the species, A. cearensis performed the best under water and salinity stress conditions.


Assuntos
Fabaceae , Tabebuia , Salinidade , Água , Tolerância ao Sal , Biodegradação Ambiental , Estresse Fisiológico
11.
J Environ Manage ; 365: 121673, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38959765

RESUMO

We used UAV-LiDAR technology and other advanced remote sensing techniques to evaluate mangrove rehabilitation projects along the eroding shoreline of the Upper Gulf of Thailand. Our results delineate the necessary biophysical conditions for successfully rehabilitating mangroves, establishing optimal conditions under which mangroves can naturally re-establish and thrive. Furthermore, we investigated the effectiveness of different coastal defense structures in fostering mangrove recolonization. Our analysis shows that nearshore breakwaters markedly outperform submerged breakwaters and bamboo fences, with a success rate of over 65% by significantly reducing wave energy that aids sediment trapping. These findings suggest that refinements in the configuration of coastal structures, including the elevation of breakwater crests and selective deployment of bamboo fences, will enhance mangrove rehabilitation success. These insights affirm the role of UAV-LiDAR surveys for optimizing mangrove restoration initiatives, thereby facilitating sustainable development for coastlines plagued by erosion. The insights gleaned offer a blueprint for bolstering the success rate of mangrove rehabilitation projects, directing them toward sustainable coastal development.


Assuntos
Conservação dos Recursos Naturais , Áreas Alagadas , Conservação dos Recursos Naturais/métodos , Tailândia , Desenvolvimento Sustentável
12.
J Environ Manage ; 353: 120140, 2024 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-38290263

RESUMO

Anthropogenic causes are overtaking natural factors to reshape patterns of biodiversity and ecosystem functioning. Mangrove reforestation aimed at reversing losses of mangroves has been conducted worldwide for several decades. However, how reforestation influences the link between ecological processes that shape community diversity and the consequent effects on ecosystem functions such as biomass production is less well known. Here we used data collected before and after mangrove planting to examine the effects of reforestation on molluscan species richness and biomass production by testing the changes in species richness, compositional similarities, distance-decay effects (community similarity decreases with increasing geographical distance) in metacommunity across a regional scale of 480 km (23-27 °N) in southeast Chinese coasts. Additionally, we further detected the impact of landscape configuration caused by different intensities of reforestation on the mollusc community. After the mangrove reforestation, mollusc species richness and biomass increased significantly. The increases in species richness and biomass of mollusc community were mediated by reducing distance-decay effect, indicating an increase in relationship strength between species richness and biomass might be associated with a decrease in distance-decay effect with rising mangrove habitat. We highlight the importance of considering the effects of anthropogenic changes on the relationship between biodiversity and ecosystem functioning. Quantifying the distance-decay effect of these influences enables management decisions about coastal restoration to be based upon ecological mechanisms rather than wishful thinking or superficial appearance.


Assuntos
Biodiversidade , Moluscos , Áreas Alagadas , Animais , Biomassa , Ecossistema
13.
J Environ Manage ; 352: 119921, 2024 Feb 14.
Artigo em Inglês | MEDLINE | ID: mdl-38219661

RESUMO

Tropical rainforests of Latin America (LATAM) are one of the world's largest carbon sinks, with substantial future carbon sequestration potential and contributing a major proportion of the global supply of forest carbon credits. LATAM is poised to contribute predominantly towards high-quality forest carbon offset projects designed to reduce emissions from deforestation and forest degradation, halt biodiversity loss, and provide equitable conservation benefits to people. Thus, carbon markets, including compliance carbon markets and voluntary carbon markets continue to expand in LATAM. However, the extent of the growth and status of forest carbon markets, pricing initiatives, stakeholders, amongst others, are yet to be explored and extensively reviewed for the entire LATAM region. Against this backdrop, we reviewed a total of 299 articles, including peer-reviewed and non-scientific gray literature sources, from January 2010 to March 2023. Herein, based on the extensive literature review, we present the results and provide perspectives classified into five categories: (i) the status and recent trends of forest carbon markets (ii) the interested parties and their role in the forest carbon markets, (iii) the measurement, reporting and verification (MRV) approaches and role of remote sensing, (iv) the challenges, and (v) the benefits, opportunities, future directions and recommendations to enhance forest carbon markets in LATAM. Despite the substantial challenges, better governance structures for forest carbon markets can increase the number, quality and integrity of projects and support the carbon sequestration capacity of the rainforests of LATAM. Due to the complex and extensive nature of forest carbon projects in LATAM, emerging technologies like remote sensing can enable scale and reduce technical barriers to MRV, if properly benchmarked. The future directions and recommendations provided are intended to improve upon the existing infrastructure and governance mechanisms, and encourage further participation from the public and private sectors in forest carbon markets in LATAM.


Assuntos
Carbono , Ecossistema , Humanos , Carbono/metabolismo , América Latina , Conservação dos Recursos Naturais/métodos , Florestas , Sequestro de Carbono
14.
Ecol Appl ; 33(6): e2897, 2023 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-37305925

RESUMO

Forest persistence in regions impacted by increasing water and temperature stress will depend upon species' ability to either rapidly adjust to novel conditions or migrate to track ecological niches. Predicted, rapid climate change is likely to outpace the adaptive and migratory capacity of long-lived isolated tree species, and reforestation may be critical to species' persistence. Facilitating persistence both within and beyond a species' range requires identification of seed lots best adapted to the current and future conditions predicted with rapid climate change. We evaluate variation in emergent seedling performance that leads to differential survival among species and populations for three high elevation five-needle pines. We paired a fully reciprocal field common garden experiment with a greenhouse common garden study to (1) quantify variation in seedling emergence and functional traits, (2) ask how functional traits affect performance under different establishment conditions, and (3) evaluate whether trait and performance variation demonstrates local adaptation and plasticity. Among study species-limber, Great Basin bristlecone, and whitebark pines-we found divergence in emergence and functional traits, though soil moisture was the strongest driver of seedling emergence and abundance across all species. Generalist limber pine had a clear emergence advantage as well as traits associated with drought adaptation, while edaphic specialist bristlecone pine was characterized by low emergence yet high early survival once established. Despite evidence for edaphic specialization, soil characteristics alone did not explain bristlecone success. Across species, trait-environment relationships provided some evidence for local adaptation in drought-adapted traits, but we found no evidence of local adaptation in emergence or survival at this early life stage. For managers looking to promote persistence, sourcing seed from drier environments is likely to impart greater drought resistance into reforestation efforts through strategies such as greater root investment, increasing the probability of early seedling survival. This research demonstrates, through a rigorous reciprocal transplant experimental design, that it may be possible to select climate- and soil-appropriate seed sources for reforestation. However, planting success will ultimately rely on a suitable establishment environment, requiring careful consideration of interannual climate variability for management interventions in these climate and disturbance-impacted tree species.

15.
Oecologia ; 201(4): 887-900, 2023 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-36977811

RESUMO

The question of whether biodiversity conservation and carbon conservation can be synergistic hinges on the form of the biodiversity-productivity relationship (BPR), a fundamental ecological pattern. The stakes are particularly high when it comes to forests, which at a global level comprises a large fraction of both biodiversity and carbon. And yet, in forests, the BPR is relatively poorly understood. In this review, we critically evaluate research on forest BPRs, focussing on the experimental and observational studies of the last 2 decades. We find general support for a positive forest BPR, suggesting that biodiversity and carbon conservation are synergistic to a degree. However, we identify several major caveats: (i) although, on average, productivity may increase with biodiversity, the highest-yielding forests are often monocultures of very productive species; (ii) productivity typically saturates at fewer than ten species; (iii) positive BPRs can be driven by some third variable, in particular stem density, instead of a causal arrow from biodiversity to productivity; (iv) the BPR's sign and magnitude varies across spatial grains and extents, and it may be weak at scales relevant to conservation; and (v) most productivity estimates in forests are associated with large errors. We conclude by explaining the importance of these caveats for both conservation programmes focussed on protection of existing forests and conservation programmes focussed on restoring or replanting forests.


Assuntos
Biodiversidade , Florestas , Conservação dos Recursos Naturais
16.
J Environ Manage ; 337: 117713, 2023 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-36958277

RESUMO

Roughly 2 billion ha of land are degraded and in need of ecological restoration worldwide. Active restoration frequently involves revegetation, which leads to the dilemma of whether to conduct direct seeding or to plant nursery-grown seedlings. The choice of revegetation method can regulate plant survival and performance, with economic implications that ultimately feed back to our capacity to conduct restoration. We followed a peer-reviewed protocol to develop a systematic map that collates, describes and catalogues the available studies on how seeding compares to planting in achieving restoration targets. We compiled a database with the characteristics of all retrieved studies, which can be searched to identify studies of particular locations and habitats, objectives of restoration, plant material, technical aspects, and outcomes measured. The search was made in eight languages and retrieved 3355 publications, of which 178 were retained. The systematic map identifies research gaps, such as a lack of studies in the global South, in tropical rainforests, and covering a long time period, which represent opportunities to expand field-based research. Additionally, many studies overlooked reporting on important technical aspects such as seed provenance and nursery cultivation methods, and others such as watering or seedling protection were more frequently applied for planting than for seeding, which limits our capacity to learn from past research. Most studies measured outcomes related to the target plants but avoided measuring general restoration outcomes or economic aspects. This represents a relevant gap in research, as the choice of revegetation method is greatly based on economic aspects and the achievement of restoration goals goes beyond the establishment of plants. Finally, we identified a substantial volume of studies conducted in temperate regions and over short periods (0-5 y). This research cluster calls for a future in-depth synthesis, potentially through meta-analysis, to reveal the overall balance between seeding and planting and assess whether the response to this question is mediated by species traits, environmental characteristics, or technical aspects. Besides identifying research clusters and gaps, the systematic map database allows managers to find the most relevant scientific literature on the appropriateness of seeding vs. planting for particular conditions, such as certain species or habitats.


Assuntos
Ecossistema , Plantas , Plântula , Sementes
17.
J Environ Manage ; 348: 119401, 2023 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-37931435

RESUMO

Afforestation and reforestation are pivotal in mitigating land degradation and bolstering the carbon sink capacity of terrestrial ecosystems. However, the potential economic ramifications of afforestation and reforestation in the context of climate change remain largely unexplored. In this study, we employed an interdisciplinary methodology to establish a framework for assessing future forest potential and carbon sequestration in the Eastern Loess Plateau region of China. Our findings indicate that an estimated 17,392.99 km2 of land suitable for afforestation still existed within the region, exhibiting a propensity to aggregate around existing forests rather than being dispersed randomly. Notably, 4385.36 km2 was prioritized for afforestation initiatives. Projections suggest a significant enhancement of the forest carbon sink within the study area by 2050, ranging from 36.93 Mt to 105.38 Mt. The corresponding economic value for this enhancement is estimated to vary between US$3.25 billion and US$17.68 billion. Of significance is the observed polarization of the region's carbon sink capacity over time, with half of the total carbon sinks concentrated within 10% of the districts. Additionally, approximately 26% of the counties are expected to transition from carbon sinks to carbon sources. These findings underscore the substantial impact of climate change on forest distribution and suggest a targeted approach to combat forest degradation by circumventing ineffective afforestation activities.


Assuntos
Sequestro de Carbono , Ecossistema , Florestas , China , Carbono/análise , Árvores/metabolismo
18.
J Environ Manage ; 328: 116866, 2023 Feb 15.
Artigo em Inglês | MEDLINE | ID: mdl-36493544

RESUMO

The reforestation value chain depends on the selection of qualified seeds supplied from various sources to ensure the successful growth, as each reforestation site has particular ecological parameters. The reforestation process usually involves many partners from different organisations, increasing the complexity of seed allocation. This research addresses seed allocation in a collaborative, make-to-order reforestation value chain. Using multi-objective optimisation models and considering different degrees of collaboration, it aims to find the most compatible seeds for each reforestation site so as to favour regeneration success. As a case study, the models are applied to the Quebec reforestation value chain which manages over 1450 seed lots and an annual production of 130 million seedlings. The process must consider two groups of partners: a seed center, and 18 nurseries. The lexicographic method is used to solve the models. Results show that an array of optimal solutions favouring reforestation success are possible by considering the main objective in each model. The second objective, integrating partners' objectives separately, modifies the initial solution significantly. Furthermore, when the objectives of both groups of partners are considered simultaneously, the proposed allocation differs depending on their priority, while the reforestation success objective does not deteriorate. The proposed set of models provide decision makers with a means to rapidly find a suitable seed allocation plan that favours reforestation success while considering partners satisfaction and existing bottlenecks in the value chain. This article contributes to the field by providing a sustainable seed allocation model favouring reforestation success covering the three pillars of sustainability.


Assuntos
Plântula , Sementes , Alocação de Recursos , Quebeque
19.
Environ Monit Assess ; 195(5): 565, 2023 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-37055670

RESUMO

Greenhouse gases (GHG) emanating from agriculture, forestry, and other land use (AFOLU) sector are among top contributors to anthropogenic climate change in Africa and globally. Minimizing AFOLU sector GHG emissions in Africa is notoriously hard because of difficulties in emission estimation, the disperse nature of AFOLU emissions, and the complex links between AFOLU activities and poverty reduction. Yet, there are very few systematic reviews dealing with decarbonization pathways for the AFOLU sector in Africa. This article explores the options for achieving deep decarbonization of AFOLU sector in Africa, through a systematic review. Using the method of Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA Statement), 46 studies of interest were selected from the databases of Scopus, Google Scholar, and Web of Science. Four sub-themes were identified from the critical review of the selected studies covering key decarbonization approaches used in AFOLU sector. The literature suggests that while forest management and reforestation reduction of GHG in animal production and climate-smart practices in agriculture hold great promises for AFOLU sector decarbonization in Africa, there appears to be very limited coherent policy in the continent addressing any of these AFOLU sub-sectors.


Assuntos
Agricultura Florestal , Gases de Efeito Estufa , Animais , Efeito Estufa , Monitoramento Ambiental , Agricultura , Gases de Efeito Estufa/análise , África , Mudança Climática
20.
Environ Monit Assess ; 195(9): 1074, 2023 Aug 24.
Artigo em Inglês | MEDLINE | ID: mdl-37615714

RESUMO

The purpose of this study was to estimate the temporal variability of CO2 emission (FCO2) from O2 influx into the soil (FO2) in a reforested area with native vegetation in the Brazilian Cerrado, as well as to understand the dynamics of soil respiration in this ecosystem. The database is composed of soil respiration data, agroclimatic variables, improved vegetation index (EVI), and soil attributes used to train machine learning algorithms: artificial neural network (ANN) and an adaptive neuro-fuzzy inference system (ANFIS). The predictive performance was evaluated based on the mean absolute error (MEA), root mean square error (RMSE), mean absolute percentage error (MAPE), agreement index (d), confidence coefficient (c), and coefficient of determination (R2). The best estimation results for validation were FCO2 with multilayer perceptron neural network (MLP) (R2 = 0.53, RMSE = 0.967 µmol m-2 s-1) and radial basis function neural network (RBF) (R2 = 0.54, RMSE = 0.884 µmol m-2 s-1) and FO2 with MLP (R2 = 0.45, RMSE = 0.093 mg m-2 s-1) and RBF (R2 = 0.74, 0.079 mg m-2 s-1). Soil temperature and macroporosity are important predictors of FCO2 and FO2. The best combination of variables for training the ANFIS was selected based on trial and error. The results were as follows: FCO2 (R2 = 16) and FO2 (R2 = 29). In all models, FCO2 outperformed FO2. A primary factor analysis was performed, and FCO2 and FO2 correlated best with the weather and soil attributes, respectively.


Assuntos
Ecossistema , Monitoramento Ambiental , Brasil , Florestas , Redes Neurais de Computação , Respiração , Solo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA