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Mata-Guel EO, Soh MCK, Butler CW, Morris RJ, Razgour O, Peh KSH. Impacts of anthropogenic climate change on tropical montane forests: an appraisal of the evidence. Biol Rev Camb Philos Soc 2023; 98:1200-1224. [PMID: 36990691 DOI: 10.1111/brv.12950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2022] [Revised: 03/08/2023] [Accepted: 03/10/2023] [Indexed: 03/31/2023]
Abstract
In spite of their small global area and restricted distributions, tropical montane forests (TMFs) are biodiversity hotspots and important ecosystem services providers, but are also highly vulnerable to climate change. To protect and preserve these ecosystems better, it is crucial to inform the design and implementation of conservation policies with the best available scientific evidence, and to identify knowledge gaps and future research needs. We conducted a systematic review and an appraisal of evidence quality to assess the impacts of climate change on TMFs. We identified several skews and shortcomings. Experimental study designs with controls and long-term (≥10 years) data sets provide the most reliable evidence, but were rare and gave an incomplete understanding of climate change impacts on TMFs. Most studies were based on predictive modelling approaches, short-term (<10 years) and cross-sectional study designs. Although these methods provide moderate to circumstantial evidence, they can advance our understanding on climate change effects. Current evidence suggests that increasing temperatures and rising cloud levels have caused distributional shifts (mainly upslope) of montane biota, leading to alterations in biodiversity and ecological functions. Neotropical TMFs were the best studied, thus the knowledge derived there can serve as a proxy for climate change responses in under-studied regions elsewhere. Most studies focused on vascular plants, birds, amphibians and insects, with other taxonomic groups poorly represented. Most ecological studies were conducted at species or community levels, with a marked paucity of genetic studies, limiting understanding of the adaptive capacity of TMF biota. We thus highlight the long-term need to widen the methodological, thematic and geographical scope of studies on TMFs under climate change to address these uncertainties. In the short term, however, in-depth research in well-studied regions and advances in computer modelling approaches offer the most reliable sources of information for expeditious conservation action for these threatened forests.
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Affiliation(s)
- Erik O Mata-Guel
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Malcolm C K Soh
- National Park Boards, 1 Cluny Road, Singapore, 259569, Singapore
| | - Connor W Butler
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Rebecca J Morris
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
| | - Orly Razgour
- Biosciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Kelvin S-H Peh
- School of Biological Sciences, University of Southampton, Highfield Campus, Southampton, SO17 1BJ, UK
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Sena PHA, Fonsêca NC, Lins-e-Silva ACB. Non-negligible role of dead organic matter in a rainforest remnant in Northeast Brazil. RODRIGUÉSIA 2022. [DOI: 10.1590/2175-7860202273041] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Abstract Dead organic matter represents an essential reservoir of carbon, especially that allocated in standing dead trees, coarse woody debris, and fine litter, playing a pivotal role in nutrient cycling and habitat provisioning. However, necromass is frequently disregarded in forest assessments. Here, we aimed to perform the first assessment of multiple necromass compartments in the Atlantic Forest of Northeast Brazil, providing a basis for future integrative studies related to necromass in this region. We registered 17 standing dead trees in 0.5 hectare and 239 logs of coarse woody debris. Necromass had 3.9 Mg.ha-1 of standing dead trees, 54.24 Mg.ha-1 of coarse woody debris and 7.2 Mg.ha-1 of litter. We indicate that standing dead trees and coarse debris were mostly in the intermediate and final stages of decomposition. Leaves were the dominant component of litter, and drier months had more litterfall. Finally, we highlight that assessing standing dead trees and coarse woody debris adds 25.6% on top of aboveground tree mass, improving information about organic matter storage in rainforest ecosystems. Our findings emphasize that the necromass compartment must be considered in forest assessments, also including small pieces of coarse woody debris, which could inform better practices of forest management.
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Impacts of slope aspects on altitudinal species richness and species composition of Narapani-Masina landscape, Arghakhanchi, West Nepal. JOURNAL OF ASIA-PACIFIC BIODIVERSITY 2021. [DOI: 10.1016/j.japb.2021.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
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Ngaba MJY, Ma XQ, Hu YL. Variability of soil carbon and nitrogen stocks after conversion of natural forest to plantations in Eastern China. PeerJ 2020; 8:e8377. [PMID: 31998558 PMCID: PMC6979407 DOI: 10.7717/peerj.8377] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 12/09/2019] [Indexed: 11/24/2022] Open
Abstract
Forest plantation, either through afforestation or reforestation, has been suggested to reverse and mitigate the process of deforestation. However, uncertainties remain in the potential of plantation forest (PF) to sequestrate carbon (C) and nitrogen (N) compared to natural forest (NF). Soil C and N stocks require a critical and updated look at what is happening especially in the context of increasing rate of land use change and climate change. The current study was conducted in China’s Eastern forest to estimate soil C and N stocks in six depth layers (0–10, 10–20, 20–40, 40–60, 60–80 and 80–100 cm) and two forest types (NF and PF) at four sites along climate factors gradient. The results showed that the overall mean soil C and N amounts to a depth of 20 cm ranged from 2.6 ± 1.1 Mg ha−1 to 38.6 ± 23.1 Mg ha−1, and soil nitrogen stock ranged from 0.2 ± 0.1 Mg ha−1 to 3.3 ± 1.5 Mg ha−1. Moreover, a loss of C stock was observed at Qingyuan (QY) by −7%, Dinghushan (DH) by −26%, Jianfengling (JF) by −13% while that of N stock was observed at QY (−8%), DH (−19%) and JF (−12%) at both depth layers. These results indicate that NFs have a better capacity to accumulate soil C and N. The soil C and N decreased from the southeast to the northeast and increased from tropical to temperate mixed forests zone in the eastern part of the study area. The C and N stock mainly occurred in the topsoil and decreased significantly with depth. Moreover, soil C and N stocks increased with age of plantation. This study provides an overview of the current spatial distribution and soil stocks of C and N, as well as the effects of environmental factors on soil C and N stocks. It also indicated that, although mean annual temperature and mean annual precipitation are the key factors affecting the variations in soil C and N, their vertical and horizontal distribution differed in various aspects.
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Affiliation(s)
- Mbezele Junior Yannick Ngaba
- Forest Ecology and Stable Isotope Research Center, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Xiang-Qing Ma
- Forest Ecology and Stable Isotope Research Center, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
| | - Ya-Lin Hu
- Forest Ecology and Stable Isotope Research Center, College of Forestry, Fujian Agriculture and Forestry University, Fuzhou, Fujian, People's Republic of China
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Abstract
Necromass has a relevant role to play in the carbon stock of forest ecosystems, especially with the increase of tree mortality due to climate change. Despite this importance, its quantification is often neglected in tropical forests. The objective of this study was to quantify the carbon storage in a secondary Atlantic Forest fragment in Viçosa, Minas Gerais, Brazil. Coarse Woody Debris (CWD), standing dead trees (snags), and litter were quantified in twenty 10 m x 50 m plots randomly positioned throughout the forest area (simple random sampling). Data were collected during 2015, from July to December. The CWD and snags volumes were determined by the Smalian method and by allometric equations, respectively. The necromass of these components was estimated by multiplying the volume by the apparent density at each decomposition classes. The litter necromass was estimated by the proportionality method and the average of the extrapolated estimates per hectare. The carbon stock of the three components was quantified by multiplying the necromass and the carbon wood content. The total volume of dead wood, including CWD and snag, was 23.6 ± 0.9 m3 ha−1, being produced mainly by the competition for resources, senescence, and anthropic and climatic disturbances. The total necromass was 16.3 ± 0.4 Mg ha−1. The total carbon stock in necromass was 7.3 ± 0.2 MgC ha−1. The CWD, snag and litter stocked 3.0 ± 0.1, 1.8 ± 0.1, and 2.5 ± 0.1 MgC ha−1, respectively. These results demonstrate that although necromass has a lower carbon stock compared to biomass, neglecting its quantification may lead to underestimation of the carbon balance of forest ecosystems and their potential to mitigate climate change.
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Padgurschi MCG, Vieira SA, Stefani EJF, Nardoto GB, Joly CA. Nitrogen input by bamboos in neotropical forest: a new perspective. PeerJ 2018; 6:e6024. [PMID: 30519513 PMCID: PMC6275114 DOI: 10.7717/peerj.6024] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Accepted: 10/24/2018] [Indexed: 11/20/2022] Open
Abstract
Background Nitrogen (N) is an important macronutrient that controls the productivity of ecosystems and biological nitrogen fixation (BNF) is a major source of N in terrestrial systems, particularly tropical forests. Bamboo dominates theses forests, but our knowledge regarding the role of bamboo in ecosystem functioning remains in its infancy. We investigated the importance of a native bamboo species to the N cycle of a Neotropical forest. Methods We selected 100 sample units (100 m2 each) in a pristine montane Atlantic Forest, in Brazil. We counted all the clumps and live culms of Merostachys neesii bamboo and calculated the specific and total leaf area, as well as litter production and respective N content. Potential N input was estimated based on available data on BNF rates for the same bamboo species, whose N input was then contextualized using information on N cycling components in the study area. Results With 4,000 live culms ha-1, the native bamboo may contribute up to 11.7 kg N ha-1 during summer (January to March) and 19.6 kg N ha-1 in winter (July to September). When extrapolated for annual values, M. neesii could contribute more than 60 kg N ha-1y-1. Discussion The bamboo species' contribution to N input may be due to its abundance (habitat availability for microbial colonization) and the composition of the free-living N fixer community on its leaves (demonstrated in previous studies). Although some N is lost during decomposition, this input could mitigate the N deficit in the Atlantic Forest studied by at least 27%. Our findings suggest that M. neesii closely regulates N input and may better explain the high diversity and carbon stocks in the area. This is the first time that a study has investigated BNF using free-living N fixers on the phyllosphere of bamboo.
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Affiliation(s)
- Maíra C G Padgurschi
- Plant Biology Department, State University of Campinas, Campinas, São Paulo, Brazil
| | - Simone A Vieira
- Center for Environmental Studies and Research, State University of Campinas, Campinas, São Paulo, Brazil
| | - Edson J F Stefani
- Plant Biology Department, State University of Campinas, Campinas, São Paulo, Brazil
| | | | - Carlos A Joly
- Plant Biology Department, State University of Campinas, Campinas, São Paulo, Brazil
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Winbourne JB, Harrison MT, Sullivan BW, Alvarez-Clare S, Lins SR, Martinelli L, Nasto M, Piotto D, Rolim S, Wong M, Porder S. A New Framework for Evaluating Estimates of Symbiotic Nitrogen Fixation in Forests. Am Nat 2018; 192:618-629. [PMID: 30332582 DOI: 10.1086/699828] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022]
Abstract
Symbiotic nitrogen fixation (SNF) makes atmospheric nitrogen biologically available and regulates carbon storage in many terrestrial ecosystems. Despite its global importance, estimates of SNF rates are highly uncertain, particularly in tropical forests where rates are assumed to be high. Here we provide a framework for evaluating the uncertainty of sample-based SNF estimates and discuss its implications for quantifying SNF and thus understanding of forest function. We apply this framework to field data sets from six lowland tropical rainforests (mature and secondary) in Brazil and Costa Rica. We use this data set to estimate parameters influencing SNF estimation error, notably the root nodule abundance and variation in SNF rates among soil cores containing root nodules. We then use simulations to gauge the relationship between sampling effort and SNF estimation accuracy for a combination of parameters. Field data illuminate a highly right-skewed lognormal distribution of SNF rates among soil cores containing root nodules that were rare and spanned five orders of magnitude. Consequently, simulations demonstrated that sample sizes of hundreds to even thousands of soil cores are needed to obtain estimates of SNF that are within, for example, a factor of 2 of the actual rate with 75% probability. This represents sample sizes that are larger than most studies to date. As a result of this previously undescribed uncertainty, we suggest that current estimates of SNF in tropical forests are not sufficiently constrained to elucidate forest stand-level controls of SNF, which hinders our understanding of the impact of SNF on tropical forest ecosystem processes.
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Zani CF, Barneze AS, Robertson AD, Keith AM, Cerri CEP, McNamara NP, Cerri CC. Vinasse application and cessation of burning in sugarcane management can have positive impact on soil carbon stocks. PeerJ 2018; 6:e5398. [PMID: 30123714 PMCID: PMC6086084 DOI: 10.7717/peerj.5398] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Accepted: 07/12/2018] [Indexed: 11/20/2022] Open
Abstract
Bioenergy crops, such as sugarcane, have the potential to mitigate greenhouse gas emissions through fossil fuel substitution. However, increased sugarcane propagation and recent management changes have raised concerns that these practices may deplete soil carbon (C) stocks, thereby limiting the net greenhouse gas benefit. In this study, we use both a measured and modelled approach to evaluate the impacts of two common sugarcane management practices on soil C sequestration potential in Brazil. We explore how transitions from conventional (mineral fertiliser/burning) to improved (vinasse application/unburned) practices influence soil C stocks in total and in physically fractionated soil down to one metre. Results suggest that vinasse application leads to an accumulation of soil C of 0.55 Mg ha-1yr-1 at 0-30 cm depth and applying unburned management led to gains of ∼0.7 Mg ha-1yr-1 at 30-60 cm depth. Soil C concentration in the Silt+Clay fraction of topsoil (0-20 cm) showed higher C content in unburned management but it did not differ under vinasse application. The CENTURY model was used to simulate the consequences of management changes beyond the temporal extent of the measurements. Simulations indicated that vinasse was not the key factor driving increases in soil C stocks but its application may be the most readily available practice to prevent the soil C losses under burned management. Furthermore, cessation of burning may increase topsoil C by 40% after ∼50 years. These are the first data comparing different sugarcane management transitions within a single area. Our findings indicate that both vinasse application and the cessation of burning can play an important role in reducing the time required for sugarcane ethanol production to reach a net C benefit (payback time).
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Affiliation(s)
- Caio F Zani
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, São Paulo, Brazil.,Lancaster Environment Centre, Centre for Ecology & Hydrology, Lancaster, United Kingdom
| | - Arlete S Barneze
- Lancaster Environment Centre, Centre for Ecology & Hydrology, Lancaster, United Kingdom.,Soil and Ecosystem Ecology Laboratory, Lancaster Environment Centre, Lancaster University, Lancaster, United Kingdom
| | - Andy D Robertson
- Lancaster Environment Centre, Centre for Ecology & Hydrology, Lancaster, United Kingdom.,Institute of Biological and Environmental Sciences, University of Aberdeen, Aberdeen, United Kingdom
| | - Aidan M Keith
- Lancaster Environment Centre, Centre for Ecology & Hydrology, Lancaster, United Kingdom
| | - Carlos E P Cerri
- Departamento de Ciência do Solo, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Piracicaba, Brazil
| | - Niall P McNamara
- Lancaster Environment Centre, Centre for Ecology & Hydrology, Lancaster, United Kingdom
| | - Carlos C Cerri
- Centro de Energia Nuclear na Agricultura, Universidade de São Paulo, Piracicaba, São Paulo, Brazil.,Departamento de Ciência do Solo, Escola Superior de Agricultura "Luiz de Queiroz", Universidade de São Paulo, Piracicaba, Brazil
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Fauset S, Freitas HC, Galbraith DR, Sullivan MJ, Aidar MP, Joly CA, Phillips OL, Vieira SA, Gloor MU. Differences in leaf thermoregulation and water use strategies between three co-occurring Atlantic forest tree species. PLANT, CELL & ENVIRONMENT 2018; 41:1618-1631. [PMID: 29603771 PMCID: PMC6032932 DOI: 10.1111/pce.13208] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/28/2017] [Revised: 03/13/2018] [Accepted: 03/22/2018] [Indexed: 05/13/2023]
Abstract
Given anticipated climate changes, it is crucial to understand controls on leaf temperatures including variation between species in diverse ecosystems. In the first study of leaf energy balance in tropical montane forests, we observed current leaf temperature patterns on 3 tree species in the Atlantic forest, Brazil, over a 10-day period and assessed whether and why patterns may vary among species. We found large leaf-to-air temperature differences (maximum 18.3 °C) and high leaf temperatures (over 35 °C) despite much lower air temperatures (maximum 22 °C). Leaf-to-air temperature differences were influenced strongly by radiation, whereas leaf temperatures were also influenced by air temperature. Leaf energy balance modelling informed by our measurements showed that observed differences in leaf temperature between 2 species were due to variation in leaf width and stomatal conductance. The results suggest a trade-off between water use and leaf thermoregulation; Miconia cabussu has more conservative water use compared with Alchornea triplinervia due to lower transpiration under high vapour pressure deficit, with the consequence of higher leaf temperatures under thermal stress conditions. We highlight the importance of leaf functional traits for leaf thermoregulation and also note that the high radiation levels that occur in montane forests may exacerbate the threat from increasing air temperatures.
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Affiliation(s)
- Sophie Fauset
- School of GeographyUniversity of LeedsLeedsLS2 9JTUK
| | - Helber C. Freitas
- Departamento de Física, Faculdade de CiênciasUniversidade Estadual PaulistaAv. Eng. Luiz Edmundo Carrijo Coube, 14‐01, BauruSão Paulo17033‐360Brazil
| | | | | | - Marcos P.M. Aidar
- Instituto de Botânica de São PauloAvenida Miguel StéfanoSão Paulo04301‐902Brazil
| | - Carlos A. Joly
- Departamento de Biologia Vegetal, Instituto de BiologiaUniversidade Estadual de CampinasRua Monteiro Lobato, Cidade Universitâria, CampinasSão Paulo13083‐862Brazil
| | | | - Simone A. Vieira
- Núcleo de Estudos e Pesquisas AmbientaisUniversidade Estadual de CampinasRua dos Flamboyants, 155, CampinasSão Paulo13083‐867Brazil
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Garcia M, Saatchi S, Ferraz A, Silva CA, Ustin S, Koltunov A, Balzter H. Impact of data model and point density on aboveground forest biomass estimation from airborne LiDAR. CARBON BALANCE AND MANAGEMENT 2017; 12:4. [PMID: 28413848 PMCID: PMC5311013 DOI: 10.1186/s13021-017-0073-1] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/17/2016] [Accepted: 02/05/2017] [Indexed: 06/07/2023]
Abstract
BACKGROUND Accurate estimation of aboveground forest biomass (AGB) and its dynamics is of paramount importance in understanding the role of forest in the carbon cycle and the effective implementation of climate change mitigation policies. LiDAR is currently the most accurate technology for AGB estimation. LiDAR metrics can be derived from the 3D point cloud (echo-based) or from the canopy height model (CHM). Different sensors and survey configurations can affect the metrics derived from the LiDAR data. We evaluate the ability of the metrics derived from the echo-based and CHM data models to estimate AGB in three different biomes, as well as the impact of point density on the metrics derived from them. RESULTS Our results show that differences among metrics derived at different point densities were significantly different from zero, with a larger impact on CHM-based than echo-based metrics, particularly when the point density was reduced to 1 point m-2. Both data models-echo-based and CHM-performed similarly well in estimating AGB at the three study sites. For the temperate forest in the Sierra Nevada Mountains, California, USA, R2 ranged from 0.79 to 0.8 and RMSE (relRMSE) from 69.69 (35.59%) to 70.71 (36.12%) Mg ha-1 for the echo-based model and from 0.76 to 0.78 and 73.84 (37.72%) to 128.20 (65.49%) Mg ha-1 for the CHM-based model. For the moist tropical forest on Barro Colorado Island, Panama, the models gave R2 ranging between 0.70 and 0.71 and RMSE between 30.08 (12.36%) and 30.32 (12.46) Mg ha-1 [between 0.69-0.70 and 30.42 (12.50%) and 61.30 (25.19%) Mg ha-1] for the echo-based [CHM-based] models. Finally, for the Atlantic forest in the Sierra do Mar, Brazil, R2 was between 0.58-0.69 and RMSE between 37.73 (8.67%) and 39.77 (9.14%) Mg ha-1 for the echo-based model, whereas for the CHM R2 was between 0.37-0.45 and RMSE between 45.43 (10.44%) and 67.23 (15.45%) Mg ha-1. CONCLUSIONS Metrics derived from the CHM show a higher dependence on point density than metrics derived from the echo-based data model. Despite the median of the differences between metrics derived at different point densities differing significantly from zero, the mean change was close to zero and smaller than the standard deviation except for very low point densities (1 point m-2). The application of calibrated models to estimate AGB on metrics derived from thinned datasets resulted in less than 5% error when metrics were derived from the echo-based model. For CHM-based metrics, the same level of error was obtained for point densities higher than 5 points m-2. The fact that reducing point density does not introduce significant errors in AGB estimates is important for biomass monitoring and for an effective implementation of climate change mitigation policies such as REDD + due to its implications for the costs of data acquisition. Both data models showed similar capability to estimate AGB when point density was greater than or equal to 5 point m-2.
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Affiliation(s)
- Mariano Garcia
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109 USA
- Department of Geography, Centre for Landscape and Climate Research, University of Leicester, Leicester, LE1 7RH UK
| | - Sassan Saatchi
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109 USA
| | - Antonio Ferraz
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109 USA
| | - Carlos Alberto Silva
- Jet Propulsion Laboratory (JPL), California Institute of Technology, Pasadena, CA 91109 USA
- US Forest Service (USDA), Rocky Mountain Research Station, RMRS, 1221 South Main Street, Moscow, ID 83843 USA
- Department of Forest, Rangeland, and Fire Sciences, College of Natural Resources, University of Idaho, (UI), 875 Perimeter Drive, Moscow, ID 83843 USA
| | - Susan Ustin
- Center for Spatial Technologies and Remote Sensing (CSTARS), University of California Davis, Davis, USA
| | - Alexander Koltunov
- Center for Spatial Technologies and Remote Sensing (CSTARS), University of California Davis, Davis, USA
| | - Heiko Balzter
- Department of Geography, Centre for Landscape and Climate Research, University of Leicester, Leicester, LE1 7RH UK
- National Centre for Earth Observation, University of Leicester, Leicester, LE1 7RH UK
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Fauset S, Gloor MU, Aidar MPM, Freitas HC, Fyllas NM, Marabesi MA, Rochelle ALC, Shenkin A, Vieira SA, Joly CA. Tropical forest light regimes in a human-modified landscape. Ecosphere 2017; 8:e02002. [PMID: 29263939 PMCID: PMC5731677 DOI: 10.1002/ecs2.2002] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2017] [Accepted: 10/02/2017] [Indexed: 11/24/2022] Open
Abstract
Light is the key energy input for all vegetated systems. Forest light regimes are complex, with the vertical pattern of light within canopies influenced by forest structure. Human disturbances in tropical forests impact forest structure and hence may influence the light environment and thus competitiveness of different trees. In this study, we measured vertical diffuse light profiles along a gradient of anthropogenic disturbance, sampling intact, logged, secondary, and fragmented sites in the biodiversity hot spot of the Atlantic forest, southeast Brazil, using photosynthetically active radiation sensors and a novel approach with estimations of vertical light profiles from hemispherical photographs. Our results show clear differences in vertical light profiles with disturbance: Fragmented forests are characterized by rapid light extinction within their low canopies, while the profiles in logged forests show high heterogeneity and high light in the mid-canopy despite decades of recovery. The secondary forest showed similar light profiles to intact forest, but with a lower canopy height. We also show that in some cases the upper canopy layer and heavy liana infestations can severely limit light penetration. Light extinction with height above the ground and depth below the canopy top was highest in fragmented forest and negatively correlated with canopy height. The novel, inexpensive, and rapid methods described here can be applied to other sites to quantify rarely measured vertical light profiles.
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Affiliation(s)
- Sophie Fauset
- School of GeographyUniversity of LeedsLeedsLS2 9JTUK
- Departamento de Biologia VegetalInstituto de BiologiaUniversidade Estadual de CampinasRua Monteiro Lobato, Cidade UniversitâriaCampinasSao Paulo13083‐862Brazil
| | | | - Marcos P. M. Aidar
- Instituto de Botânica de São PauloAvenida Miguel StéfanoSao Paulo04301‐902Brazil
| | - Helber C. Freitas
- Departamento de FísicaFaculdade de CiênciasUniversidade Estadual PaulistaAvenida Engenheiro Luiz Edmundo Carrijo Coube, 14‐01BauruSao Paulo17033‐360Brazil
- Centro de Meteorologia – IPMet/UNESPEstrada Municipal José SandrinBauruSao Paulo17048‐699Brazil
| | - Nikolaos M. Fyllas
- School of GeographyUniversity of LeedsLeedsLS2 9JTUK
- Environmental Change InstituteSchool of Geography and the EnvironmentUniversity of OxfordSouth Parks RoadOxfordOX1 3QYUK
| | - Mauro A. Marabesi
- Departamento de Biologia VegetalInstituto de BiologiaUniversidade Estadual de CampinasRua Monteiro Lobato, Cidade UniversitâriaCampinasSao Paulo13083‐862Brazil
- Instituto de Botânica de São PauloAvenida Miguel StéfanoSao Paulo04301‐902Brazil
| | - André L. C. Rochelle
- Departamento de Biologia VegetalInstituto de BiologiaUniversidade Estadual de CampinasRua Monteiro Lobato, Cidade UniversitâriaCampinasSao Paulo13083‐862Brazil
| | - Alexander Shenkin
- Environmental Change InstituteSchool of Geography and the EnvironmentUniversity of OxfordSouth Parks RoadOxfordOX1 3QYUK
| | - Simone A. Vieira
- Núcleo de Estudos e Pesquisas AmbientaisUniversidade Estadual de CampinasRua dos Flamboyants, 155CampinasSao Paulo13083‐867Brazil
| | - Carlos A. Joly
- Departamento de Biologia VegetalInstituto de BiologiaUniversidade Estadual de CampinasRua Monteiro Lobato, Cidade UniversitâriaCampinasSao Paulo13083‐862Brazil
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Litterfall mass and nutrient fluxes over an altitudinal gradient in the coastal Atlantic Forest, Brazil. JOURNAL OF TROPICAL ECOLOGY 2017. [DOI: 10.1017/s0266467417000207] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Abstract:Litterfall is one of the most important pathways through which nutrients are recycled in the terrestrial biosphere. In tropical soils, which are generally low in essential nutrients such as phosphorus and cations, the flux of nutrients through litterfall is particularly important to sustaining CO2-uptake capacity; however, questions remain over the role of altitude in altering litter nutrient cycling rates among tropical forest ecosystems. Here we examine litterfall, carbon (C), nitrogen (N) and phosphorus (P) fluxes through litterfall over an altitudinal gradient in the coastal Atlantic Forest located on the northern coast of the State of São Paulo, Brazil. Litterfall was collected twice a month for 1 y (April 2007–March 2008) using 30 litter traps placed in four different forest types arrayed by altitude – coastal forest (sea level), lowland forest (50–200 m asl), submontane forest (300–500 m asl) and montane forest (1000 m asl). Litterfall mass-fluxes decreased with increasing altitude, from ~9 Mg ha−1 in lowland forests to 7 Mg ha−1 in higher-altitude ecosystems. Contribution of reproductive organs to litterfall was significantly greater in lower than in higher altitudes. Litterfall N and P fluxes were higher in the lowland forest vs. other forest types, pointing to strong altitudinal controls over nutrient cycling. Furthermore, nitrogen-use efficiency (NUE) was lower and litter δ15N was higher in the lowland site providing additional evidence for lack of N constraints to productivity in lowland of the south-eastern Atlantic Forest.
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Nagy RC, Rastetter EB, Neill C, Porder S. Nutrient limitation in tropical secondary forests following different management practices. ECOLOGICAL APPLICATIONS : A PUBLICATION OF THE ECOLOGICAL SOCIETY OF AMERICA 2017; 27:734-755. [PMID: 27930831 DOI: 10.1002/eap.1478] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Revised: 10/12/2016] [Accepted: 10/25/2016] [Indexed: 06/06/2023]
Abstract
Secondary forests now make up more than one-half of all tropical forests, and constraints on their biomass accumulation will influence the strength of the terrestrial carbon (C) sink in the coming decades. However the variance in secondary tropical forest biomass for a given stand age and climate is high and our understanding of why is limited. We constructed a model of terrestrial C, nitrogen (N), and phosphorus (P) cycling to examine the influence of disturbance and management practices on nutrient limitation and biomass recovery in secondary tropical forests. The model predicted that N limited the rate of forest recovery in the first few decades following harvest, but that this limitation switched to P approximately 30-40 yr after abandonment, consistent with field data on N and P cycling from secondary tropical forest chronosequences. Simulated biomass recovery agreed well with field data of biomass accumulation following harvest (R2 = 0.80). Model results showed that if all biomass remained on site following a severe disturbance such as blowdown, regrowth approached pre-disturbance biomass in 80-90 yr, and recovery was faster following smaller disturbances such as selective logging. Field data from regrowth on abandoned pastures were consistent with simulated losses of nutrients in soil organic matter, particularly P. Following any forest disturbance that involved the removal of nutrients (i.e., except blowdown), forest regrowth produced reduced biomass relative to the initial state as a result of nutrient loss through harvest, leaching and/or sequestration by secondary minerals. Differences in nutrient availability accounted for 49-94% of the variance in secondary forest biomass C at a given stand age. Management lessons from this study are the importance of strategies that help retain nutrients on site, recognizing the role of coarse woody debris in immobilization and subsequent release of nutrients, and the potential for nutrient additions to enhance biomass growth and recovery in secondary tropical forests.
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Affiliation(s)
- R Chelsea Nagy
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, 02912, USA
- Marine Biological Laboratory, The Ecosystems Center, Woods Hole, Massachusetts, 02543, USA
| | - Edward B Rastetter
- Marine Biological Laboratory, The Ecosystems Center, Woods Hole, Massachusetts, 02543, USA
| | - Christopher Neill
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, 02912, USA
- Marine Biological Laboratory, The Ecosystems Center, Woods Hole, Massachusetts, 02543, USA
- Woods Hole Research Center, Woods Hole, Massachusetts, 02543, USA
| | - Stephen Porder
- Department of Ecology and Evolutionary Biology, Brown University, Providence, Rhode Island, 02912, USA
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Shedayi AA, Xu M, Naseer I, Khan B. Altitudinal gradients of soil and vegetation carbon and nitrogen in a high altitude nature reserve of Karakoram ranges. SPRINGERPLUS 2016; 5:320. [PMID: 27066349 PMCID: PMC4788676 DOI: 10.1186/s40064-016-1935-9] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 02/24/2016] [Indexed: 11/13/2022]
Abstract
This study aimed to investigate the correlation of carbon and nitrogen in soil and leaves with the altitude, vegetation type, herbaceous biomass (HB), litter mass (LM) and with each other. Soil and leaf samples collected from different forest types along altitudinal gradients in the Karakoram Mountains. Dry and gas law methods were used for the chemical analysis. Regression models used for correlation analysis and T test for comparison. The correlation of soil total carbon (STC) and soil total nitrogen (STN) along altitudinal gradients and correlation between soil organic carbon (SOC) and STN was significantly positive with the values R2 = 0.1684, p = 0.01, R2 = 0.1537, p = 0.009 and R2 = 0.856, p = 7.31E−10 respectively, while it was non-significant between soil inorganic carbon (SIC) and altitude and also between SIC and STN. The concentration of SOC and STN was highest in the broad leaved Betula utilis forest (22.31, 1.6 %) and least in the mixed (Pinus, Juniper, Betula) forest soil (0.85, 0.09 %) respectively. In the tree species leaf total carbon (LTC) and leaf total nitrogen (LTN) were highest in the Pinus wallichiana (PW) (632.54, 19.77), and least in the Populus alba (87.59, 4.06). In the shrub species LTC and LTN nitrogen were highest in the Rosa webiana (235.64, 7.45) and least in the Astragalus gilgitensis (43.45, 1.60) respectively. Total carbon and total nitrogen showed a slightly decreasing and increasing trend with altitude in the leaf and soil samples, respectively. The mean nitrogen and carbon was higher in the leaves of trees (3, 97.95) than in the shrubs (2.725, 74.24) and conifers (2.26, 76.46) than in the leaves of the deciduous (2, 46.36) trees. The correlation between LTC and STN was non-significant. Strong significant (R2 = 0.608, p = 0.003) and weak non-significant (R2 = 0.04, p = 0.32) relationships were found in STN and STC with LM and HB respectively. SOC (75.15 %) was found to be the main contributor to the STC (76.20 %) as compared to the SIC (1.05 %). Furthermore, SOC (75.15 %) was the major constituent to the soil organic matter (SOM) as compared to the STN (5.85 %). The vegetation type and litter both showed high impact on STN and STC, while altitude and HB showed very little or no impact on carbon and nitrogen concentrations. However, altitude puts great impact on shaping vegetation structure due to decreasing temperature along the elevation and other climatic factors which are further responsible in controlling the carbon and nitrogen concentration.
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Affiliation(s)
- Arshad Ali Shedayi
- Key Laboratory of Ecosystem Network Observation and Modeling, Institute of Geographic Sciences and Natural Resources Research, University of Chinese Academy of Sciences, Beijing, China ; Department of Biological Sciences, Karakoram International University, Gilgit, Pakistan
| | - Ming Xu
- Department of Ecology, Evolution and Natural Resources, School of Environmental and Biological Sciences, Rutgers University, New Brunswick, NJ USA
| | - Iqnaa Naseer
- Department of Botany, University of Gujrat, Gujrat city, Pakistan
| | - Babar Khan
- Gilgit conservation and information centre, WWF, Gilgit, Pakistan
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Shanafelt DW, Dieckmann U, Jonas M, Franklin O, Loreau M, Perrings C. Biodiversity, productivity, and the spatial insurance hypothesis revisited. J Theor Biol 2015; 380:426-35. [PMID: 26100182 DOI: 10.1016/j.jtbi.2015.06.017] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2014] [Revised: 06/09/2015] [Accepted: 06/10/2015] [Indexed: 11/15/2022]
Abstract
Accelerating rates of biodiversity loss have led ecologists to explore the effects of species richness on ecosystem functioning and the flow of ecosystem services. One explanation of the relationship between biodiversity and ecosystem functioning lies in the spatial insurance hypothesis, which centers on the idea that productivity and stability increase with biodiversity in a temporally varying, spatially heterogeneous environment. However, there has been little work on the impact of dispersal where environmental risks are more or less spatially correlated, or where dispersal rates are variable. In this paper, we extend the original Loreau model to consider stochastic temporal variation in resource availability, which we refer to as "environmental risk", and heterogeneity in species dispersal rates. We find that asynchronies across communities and species provide community-level stabilizing effects on productivity, despite varying levels of species richness. Although intermediate dispersal rates play a role in mitigating risk, they are less effective in insuring productivity against global (metacommunity-level) than local (individual community-level) risks. These results are particularly interesting given the emergence of global sources of risk such as climate change or the closer integration of world markets. Our results offer deeper insights into the Loreau model and new perspectives on the effectiveness of spatial insurance in the face of environmental risks.
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Affiliation(s)
- David W Shanafelt
- Arizona State University, School of Life Sciences, PO Box 874601, Tempe, AZ 85287, USA.
| | | | | | | | - Michel Loreau
- Station d׳Ecologie Expérimentale du CNRS, 09200 Moulis, France.
| | - Charles Perrings
- Arizona State University, School of Life Sciences, PO Box 874601, Tempe, AZ 85287, USA.
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Joly CA, Metzger JP, Tabarelli M. Experiences from the Brazilian Atlantic Forest: ecological findings and conservation initiatives. THE NEW PHYTOLOGIST 2014; 204:459-473. [PMID: 25209030 DOI: 10.1111/nph.12989] [Citation(s) in RCA: 133] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/03/2014] [Indexed: 06/03/2023]
Abstract
The Brazilian Atlantic Forest hosts one of the world's most diverse and threatened tropical forest biota. In many ways, its history of degradation describes the fate experienced by tropical forests around the world. After five centuries of human expansion, most Atlantic Forest landscapes are archipelagos of small forest fragments surrounded by open-habitat matrices. This 'natural laboratory' has contributed to a better understanding of the evolutionary history and ecology of tropical forests and to determining the extent to which this irreplaceable biota is susceptible to major human disturbances. We share some of the major findings with respect to the responses of tropical forests to human disturbances across multiple biological levels and spatial scales and discuss some of the conservation initiatives adopted in the past decade. First, we provide a short description of the Atlantic Forest biota and its historical degradation. Secondly, we offer conceptual models describing major shifts experienced by tree assemblages at local scales and discuss landscape ecological processes that can help to maintain this biota at larger scales. We also examine potential plant responses to climate change. Finally, we propose a research agenda to improve the conservation value of human-modified landscapes and safeguard the biological heritage of tropical forests.
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Affiliation(s)
- Carlos A Joly
- Department of Plant Biology, Biology Institute, State University of Campinas/UNICAMP, PO Box 6109, 13083-970, Campinas, SP, Brazil
| | - Jean Paul Metzger
- Departamento de Ecologia, Instituto de Biociências, Universidade de São Paulo, Rua do Matão, 321, Travessa 14, 05508-900, São Paulo, SP, Brazil
| | - Marcelo Tabarelli
- Departamento de Botânica, Universidade Federal de Pernambuco, 50670-901, Recife, PE, Brazil
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Pacchioni RG, Carvalho FM, Thompson CE, Faustino ALF, Nicolini F, Pereira TS, Silva RCB, Cantão ME, Gerber A, Vasconcelos ATR, Agnez-Lima LF. Taxonomic and functional profiles of soil samples from Atlantic forest and Caatinga biomes in northeastern Brazil. Microbiologyopen 2014; 3:299-315. [PMID: 24706600 PMCID: PMC4082704 DOI: 10.1002/mbo3.169] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2013] [Revised: 02/23/2014] [Accepted: 02/25/2014] [Indexed: 12/20/2022] Open
Abstract
Although microorganisms play crucial roles in ecosystems, metagenomic analyses of soil samples are quite scarce, especially in the Southern Hemisphere. In this work, the microbial diversity of soil samples from an Atlantic Forest and Caatinga was analyzed using a metagenomic approach. Proteobacteria and Actinobacteria were the dominant phyla in both samples. Among which, a significant proportion of stress-resistant bacteria associated to organic matter degradation was found. Sequences related to metabolism of amino acids, nitrogen, and DNA and stress resistance were more frequent in Caatinga soil, while the forest sample showed the highest occurrence of hits annotated in phosphorous metabolism, defense mechanisms, and aromatic compound degradation subsystems. The principal component analysis (PCA) showed that our samples are close to the desert metagenomes in relation to taxonomy, but are more similar to rhizosphere microbiota in relation to the functional profiles. The data indicate that soil characteristics affect the taxonomic and functional distribution; these characteristics include low nutrient content, high drainage (both are sandy soils), vegetation, and exposure to stress. In both samples, a rapid turnover of organic matter with low greenhouse gas emission was suggested by the functional profiles obtained, reinforcing the importance of preserving natural areas.
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Affiliation(s)
- Ralfo G Pacchioni
- Department of Cellular Biology and Genetics, UFRN, Natal, Rio Grande do Norte, Brazil
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Abstract
Mangroves are ecologically and economically important forests of the tropics. They are highly productive ecosystems with rates of primary production equal to those of tropical humid evergreen forests and coral reefs. Although mangroves occupy only 0.5% of the global coastal area, they contribute 10-15% (24 Tg C y(-1)) to coastal sediment carbon storage and export 10-11% of the particulate terrestrial carbon to the ocean. Their disproportionate contribution to carbon sequestration is now perceived as a means for conservation and restoration and a way to help ameliorate greenhouse gas emissions. Of immediate concern are potential carbon losses to deforestation (90-970 Tg C y(-1)) that are greater than these ecosystems' rates of carbon storage. Large reservoirs of dissolved inorganic carbon in deep soils, pumped via subsurface pathways to adjacent waterways, are a large loss of carbon, at a potential rate up to 40% of annual primary production. Patterns of carbon allocation and rates of carbon flux in mangrove forests are nearly identical to those of other tropical forests.
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Affiliation(s)
- Daniel M Alongi
- Australian Institute of Marine Science, Townsville 4810, Australia;
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Villela DM, Mattos EAD, Pinto AS, Vieira SA, Martinelli LA. Carbon and nitrogen stock and fluxes in coastal Atlantic Forest of southeast Brazil: potential impacts of climate change on biogeochemical functioning. BRAZ J BIOL 2013; 72:633-42. [PMID: 23011294 DOI: 10.1590/s1519-69842012000400003] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2012] [Accepted: 02/27/2012] [Indexed: 11/22/2022] Open
Abstract
The Atlantic Forest is one of the most important biomes of Brazil. Originally covering approximately 1.5 million of km², today this area has been reduced to 12% of its original size. Climate changes may alter the structure and the functioning of this tropical forest. Here we explore how increases in temperature and changes in precipitation distribution could affect dynamics of carbon and nitrogen in coastal Atlantic Forest of the southeast region of Brazil The main conclusion of this article is that the coastal Atlantic Forest has high stocks of carbon and nitrogen above ground, and especially, below ground. An increase in temperature may transform these forests from important carbon sinks to carbon sources by increasing loss of carbon and nitrogen to the atmosphere. However, this conclusion should be viewed with caution because it is based on limited information. Therefore, more studies are urgently needed to enable us to make more accurate predictions.
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Affiliation(s)
- D M Villela
- Laboratório de Ciências Ambientais, Centro de Biociências e Biotecnologia, Universidade Estadual do Norte Fluminense Darcy Ribeiro, Campos dos Goytacazes, RJ, Brazil.
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The Carbon Balance of Tropical Mountain Forests Along an Altitudinal Transect. ECOSYSTEM SERVICES, BIODIVERSITY AND ENVIRONMENTAL CHANGE IN A TROPICAL MOUNTAIN ECOSYSTEM OF SOUTH ECUADOR 2013. [DOI: 10.1007/978-3-642-38137-9_10] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/04/2022]
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Joly CA, Assis MA, Bernacci LC, Tamashiro JY, Campos MCRD, Gomes JAMA, Lacerda MS, Santos FAMD, Pedroni F, Pereira LDS, Padgurschi MDCG, Prata EMB, Ramos E, Torres RB, Rochelle A, Martins FR, Alves LF, Vieira SA, Martinelli LA, Camargo PBD, Aidar MPM, Eisenlohr PV, Simões E, Villani JP, Belinello R. Florística e fitossociologia em parcelas permanentes da Mata Atlântica do sudeste do Brasil ao longo de um gradiente altitudinal. BIOTA NEOTROPICA 2012. [DOI: 10.1590/s1676-06032012000100012] [Citation(s) in RCA: 52] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Este trabalho resume os dados de florística e fitossociologia de 11, das 14 parcelas de 1 ha, alocadas ao longo do gradiente altitudinal da Serra do Mar, São Paulo, Brasil. As parcelas começam na cota 10 m (Floresta de Restinga da Praia da Fazenda, município de Ubatuba) e estão distribuídas até a cota 1100 m (Floresta Ombrófila Densa Montana da Trilha do rio Itamambuca, município de São Luis do Paraitinga) abrangendo os Núcleos Picinguaba e Santa Virgínia do Parque Estadual da Serra do Mar. Na Restinga o solo é Neossolo Quartzarênico francamente arenoso, enquanto que na encosta o solo é um Cambisolo Háplico Distrófico argilo-arenoso, sendo que todas as parcelas apresentaram solo ácido (pH 3 - 4) com alta diluição de nutrientes e alta saturação de alumínio. Na Restinga e no sopé da encosta o clima é Tropical/Subtropical Úmido (Af/Cfa), sem estação seca, com precipitação média anual superior a 2.200 mm e temperatura média anual de 22 ºC. Subindo a encosta mantêm-se a média de precipitação, mas há um gradativo resfriamento, de forma que a 1.100 m o clima é Subtropical Úmido (Cfa/Cfb), sem estação seca, com temperatura média anual de 17 ºC. Destaca-se ainda que, quase diariamente, a parte superior da encosta, geralmente acima de 400 m, é coberta por uma densa neblina. Nas 14 parcelas foram marcados, medidos e amostrados 21.733 indivíduos com DAP > 4,8 cm, incluindo árvores, palmeiras e fetos arborescentes. O número médio de indivíduos amostrados nas 14 parcelas foi de 1.264 ind.ha-1 (± 218 EP de 95%). Dentro dos parâmetros considerados predominaram as árvores (71% FOD Montana a 90% na Restinga), seguidas de palmeiras (10% na Restinga a 25% na FOD Montana) e fetos arborescentes (0% na Restinga a 4% na FOD Montana). Neste aspecto destaca-se a FOD Terras Baixas Exploradas com apenas 1,8% de palmeiras e surpreendentes 10% de fetos arborescentes. O dossel é irregular, com altura variando de 7 a 9 m, raramente as árvores emergentes chegam a 18 m, e a irregularidade do dossel permite a entrada de luz suficiente para o desenvolvimento de centenas de espécies epífitas. Com exceção da FOD Montana, onde o número de mortos foi superior a 5% dos indivíduos amostrados, nas demais fitofisionomias este valor ficou abaixo de 2,5%. Nas 11 parcelas onde foi realizado o estudo florístico foram encontradas 562 espécies distribuídas em 195 gêneros e 68 famílias. Apenas sete espécies - Euterpe edulis Mart. (Arecaceae), Calyptranthes lucida Mart. ex DC. e Marlierea tomentosa Cambess (ambas Myrtaceae), Guapira opposita (Vell.) Reitz (Nyctaginaceae), Cupania oblongifolia Mart. (Sapindaceae) e as Urticaceae Cecropia glaziovii Snethl. e Coussapoa microcarpa (Schott) Rizzini - ocorreram da Floresta de Restinga à FOD Montana, enquanto outras 12 espécies só não ocorreram na Floresta de Restinga. As famílias com o maior número de espécies são Myrtaceae (133 spp), Fabaceae (47 spp), Rubiaceae (49) e Lauraceae (49) ao longo de todo gradiente da FOD e Monimiaceae (21) especificamente nas parcelas da FOD Montana. Em termos de número de indivíduos as famílias mais importantes foram Arecaceae, Rubiaceae, Myrtaceae, Sapotaceae, Lauraceae e na FOD Montana, Monimiaceae. Somente na parcela F, onde ocorreu exploração de madeira entre 1960 e 1985, a abundância de palmeiras foi substituída pelas Cyatheaceae. O gradiente estudado apresenta um pico da diversidade e riqueza nas altitudes intermediárias (300 a 400 m) ao longo da encosta (índice de Shannon-Weiner - H' - variando de 3,96 a 4,48 nats.indivíduo -1). Diversas explicações para este resultado são apresentadas neste trabalho, incluindo o fato dessas altitudes estarem nos limites das expansões e retrações das diferentes fitofisionomias da FOD Atlântica durante as flutuações climáticas do Pleistoceno. Os dados aqui apresentados demonstram a extraordinária riqueza de espécies arbóreas da Floresta Ombrófila Densa Atlântica dos Núcleos Picinguaba e Santa Virgínia do Parque Estadual da Serra do Mar, reforçando a importância de sua conservação ao longo de todo o gradiente altitudinal. A diversidade desta floresta justifica também o investimento de longo prazo, através de parcelas permanentes, para compreender sua dinâmica e funcionamento, bem como monitorar o impacto das mudanças climáticas nessa vegetação.
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