Forest Ecology

Regional Variation In Forest Health Under Long-Term Air Pollution Mitigated by Lithological Conditions (2004)

by Mark Purdon

Full Reference:
Purdon, M., Cienciala, E., Metelka, V., Beranová, J., Hunová, I. and Cerny, M. (2004) Regional variation in forest health under long-term air pollution. Forest Ecology and Management, 195(3): 355-372.

Forest defoliation and discoloration have been monitored extensively in Europe over the past decade, yet the number of... more Forest defoliation and discoloration have been monitored extensively in Europe over the past decade, yet the number of published studies seeking to interpret these data in light of environmental parameters such as lithology and airborne pollution are few. In this study we summarize and compare data on defoliation and discoloration of Norway spruce dominated stands from three regions of the Czech Republic that differ in their lithology. In the Šumava and Krkonoše regions these measures increased over the monitoring period, which is interpreted as an effect of residual soil acidification. At Beskydy, a general stability in forest health parameters was observed. Regional differences are attributed to underlying lithography—the greater calcium carbonate content of the flysch bedrock at Beskydy provides better buffering against acid deposition. These results are supported by evidence of similar trends in atmospheric pollution (ambient air concentrations and deposition) between Beskydy and the Krkonoše region and higher sulphur inputs than at Šumava. Stand elevation and age, collected as explanatory variables, did not affect this interpretation. Additionally, in the Krkonoše region forest health data were examined for four soil type categories (extreme, acidic, enriched and nutritive) specific to forest conditions in the Czech Republic. Simple time series analysis of defoliation and discoloration demonstrated that extreme and acidic soils accounted for the majority of the increasing trend of forest decline in Krkonoše. However, multivariate non-linear regression analysis using elevation and stand age revealed that defoliation was not significantly different between acidic and nutritive soil type categories; rather, this was an artefact of the experimental design. The implications of the research are that acidic and nutritive soil type categories respond similarly to acid deposition while enriched, the most nutrient rich type category is most resistant. As such our results support the interpretation that lithology is a factor mitigating forest decline in Norway spruce dominated forests in the Czech Republic. Our results have implications for zonation strategies like those being used in Krkonoše National Park which seek to prescribe specific restoration measures based upon abiotic factors for acid-damaged forests.

A percepção na transformação da paisagem: os agricultores no desflorestamento de Engenheiro Beltrão - Paraná, 1948-1970

by Eunice Nodari

CARVALHO, Ely Bergo de; NODARI, Eunice Sueli

The agricultural boundary expansion is the main deforestation cause in Brazil and studying the farmers’ perception is... more The agricultural boundary expansion is the main deforestation cause in Brazil and studying the farmers’ perception is fundamental to understand such process. This environmental history research is limited to Engenheiro Beltrão City, located in Paraná, from 1984, which was the beginning of the guided colonization, to 1970. It was used the oral history methodology, by the elaboration of 37 interviews. The main objective is to understand how the farmers have appropriated the forest and represented themselves to it.

Spatial, temporal and economic constraints to the commercial extraction of a non-timber forest product: copaíba (Copaifera spp.) oleoresin in Amazonian reserves

by Pete Newton

Authors: Newton, P., Watkinson, A.R., Peres, C.A.
Journal: Economic Botany
DOI: 10.1007/s12231-012-9198-z

The increasing prevalence of government- and NGO-sponsored programs to encourage commercial non-timber forest product... more The increasing prevalence of government- and NGO-sponsored programs to encourage commercial non-timber forest product (NTFP) extractivism in the humid tropics has highlighted the need for ecological and socioeconomic appraisal of the viability of extractive industries. We adopted a novel, integrative approach to examining NTFP resource potential and produced credible landscape-scale estimates of the projected value of an economically important Amazonian NTFP, the medicinal oleoresin of Copaifera trees, within two large contiguous extractive reserves in Brazilian Amazonia. We integrated results derived from previous spatial ecology and harvesting studies with socioeconomic and market data, and mapped the distribution of communities within the reserves. We created anisotropic accessibility models which determined the spatial and temporal access to Copaifera trees in permanently unflooded (terra firme) and seasonally-flooded (várzea) forest. Just 64.9% of the total reserve area was accessible, emphasizing the distinction between the actual resource stock and that which is available to extractors. The density of productive tree species was higher in várzea forest but per tree productivity was greater in terra firme forest, resulting in similar estimates of oleoresin yield per unit area (64 – 67 ml ha–1) in both forest types. A greater area of várzea forest was accessible within shorter travel times of ≤250 min; longer travel times allowed access to increasingly greater volumes of oleoresin from terra firme forest. The estimated total volume of oleoresin accessible within the two reserves was 38,635 liters for an initial harvest, with projected offtake for a subsequent harvest falling to 8,274 liters. A household that extracted just two liters of oleoresin per month could generate 5% of its mean income; market data suggested that certification could increase the value of the resource five-fold. Our approach is valuable in that it incorporates a range of methodologies and quantitatively accounts for the numerous constraints to the commercial viability of NTFP extraction.

Cross-scale variation in the density and spatial distribution of an Amazonian non-timber forest resource

by Pete Newton

Authors: Newton, P., Peres C.A., Desmoulière, S.J.M., Watkinson, A.R.
Journal: Forest Ecology and Management
Volume: 276
Pages: 41-51

Successful management of tropical forest resources depends upon an understanding of their patterns of density and... more Successful management of tropical forest resources depends upon an understanding of their patterns of density and spatial distribution, since these affect the potential for harvesting. The variation in these patterns across different spatial scales has rarely been explored. We assessed the extent to which different spatial scales are useful in understanding resource distribution, using the example of an economically significant tropical tree genus, Copaifera, which is valued across Brazilian Amazonia for its medicinal oleoresin. We mapped the spatial distribution of Copaifera trees at three nested spatial scales: basin-wide (across Brazilian Amazonia), landscape (across two contiguous extractive reserves) and local (within a 100-ha plot). Using data from our own study and an Amazon-wide forest inventory (Projeto RADAMBRASIL), we quantified the population distribution, density and size structure at the genus and species level at all three scales, relating these to two environmental variables – forest type and elevation. Spatial statistics were used to further characterize the resource at the landscape and local levels. The distribution, density and adult population structure differed between species and forest types at all three spatial scales. Overall tree densities ranged from 0.37 ha–1 (basin-wide scale) to 1.13 ha–1 (local scale) but varied between forest types, with várzea containing a Copaifera tree density just 43% of that in terra firme forest at the landscape scale. Spatial distribution analyses showed significant clumping of some species, especially C. multijuga which averaged 61 m between neighbouring trees. We compare our cross-scale density estimates and discuss the relative merits of studying the distribution of non-timber forest products (NTFP) at more than one spatial scale. Our results have implications for the management and extraction of this important Amazonian forest resource.

Quelles ressources génétiques pour le sapin face aux changements climatiques ?

by hendrik davi

Les dépérissements du sapin pectiné dans son aire méridionale préfigurent peut-être un risque accru pour cette... more Les dépérissements du sapin pectiné dans son aire méridionale préfigurent peut-être un risque accru pour cette espèce sur le reste du territoire dans le cadre des changements climatiques. Ce projet, financé par le RMT issu d’une collaboration entre l’Inra, l’IDF et l’ONF, étudie les potentialités d’adaptation aux changements climatiques à partir des ressources génétiques existantes au sein du genre Abies.

Germination response to collection date and storage methods in neem (Azadirachta indica A. Juss.).

by Neeraj Khera

Germination of some multipurpose tree species in five provenances in response to variation in light, temperature, substrate and water stress

by Neeraj Khera

Stand structure and plant species diversity in managed and abandoned silver fir mature woodlands

by Tommaso Sitzia

Sitzia T., Trentanovi G., Dainese M., Gobbo G., Lingua E., Sommacal M. (2012) Forest Ecology and Management 270: 232-238

Although few undisturbed forests remain in Europe, forest reserves and deforested areas that are no longer profitable... more Although few undisturbed forests remain in Europe, forest reserves and deforested areas that are no longer profitable have the potential to develop stand structures similar to those which preceded human disturbances. The direct effects of management cessation on forest diversity are confounded by many factors that should be controlled when comparing managed and abandoned stands. In the European Alps, however, the high variability of habitats makes it nearly impossible to find comparable stands located within forests large enough to be independent from the surrounding land. The aim of this study was to investigate the use of mixed models to compare deadwood and plant diversity between matched managed and unmanaged pairs of forests, with the hypothesis that their differences were due to direct effect of abandonment. Two neighbouring watersheds that were large enough to be independent from the surrounding forests were chosen. These watersheds had a common history of use, but one was non-intensively managed, while the other was untouched since 1957. Ten plots were randomly selected from each forest. Mixed models confirmed their matched topography and stand structure, while a similarity index confirmed their assignment to the same plant community. The unmanaged stand had higher soil nitrogen, higher Fagus sylvatica dendrological composition, higher tree species richness, higher dead logs and a different composition of the tree and understory layers. These results suggest that silver fir woodlands abandoned for more than 50years change spontaneously and that this approach may be an effective means for studying other forest communities.

Tribal and state ecosystem management regimes influence forest regeneration

by Nick Reo

Nick Reo and Jason Karl, Forest Ecology and Management 2010

Wild ungulates such as white-tailed deer (Odocoileus virginianus) are highly valued wildlife assets that provide... more Wild ungulates such as white-tailed deer (Odocoileus virginianus) are highly valued wildlife assets that provide subsistence, economic and cultural benefits to hunters and rural communities. Yet, high density populations of these herbivores can contribute significantly to regeneration failures in a wide range of forest types. Pre-European settlement white-tailed deer densities were estimated to have been approximately 2-4 deer km-2, and similar densities have been recommended to balance contemporary forest regeneration and wildlife objectives.

We studied northern red oak (Quercus rubra L.) regeneration on neighboring tribal and state forests where socio-cultural differences have led to distinct hunting management practices and subsequent differences in wildlife-plant interactions. Tribes such as the Lac du Flambeau Chippewa have kept deer populations relatively low on reservation lands through active hunting practices. We used an observational study approach to compare in situ ungulate herbivory under low (2-3 deer km-2) and high (>10 deer km-2) population densities. We measured northern red oak regeneration on tribal and state forests in two management unit types: contiguous stands of oak >15 ha in area and small residual “pockets” of oak < 3 ha left by foresters as a source of seed and wildlife mast. Herbivory levels were significantly higher on state forests than tribal forests and were closely correlated with the density of larger seedlings, particularly in oak pockets. If herbivory levels are too high, even with adequate light, our results suggest that seedlings may not survive in densities sufficient to maintain northern red oak as a co-dominant species in mixed forests. However, when deer densities are kept at 2-4 deer km-2, our results suggest that northern red oak seedlings can survive beyond browseable heights in sufficient numbers for maintaining oak. Tribal lands can provide contemporary examples of longstanding low to intermediate deer densities and sustainable deer-forest relationships.

Forest At Work: Conservation And Sustainable Management Of The Former Finch Pruyn Lands

by Rachel Neugarten

M.S. Thesis, published by Cornell University 2010 (no access until 2015)

Major selloffs of industrial timberlands in the U.S. in the past two decades have prompted environmental concerns... more Major selloffs of industrial timberlands in the U.S. in the past two decades have prompted environmental concerns about fragmentation and conversion of forest lands, as well as social and economic concerns about the loss of traditional livelihoods in forestry and rural community decline. In an effort to maintain intact forests and the many ecological and socioeconomic values they provide, conservation organizations, public agencies, and local communities are investing in complex "working forest" land deals in which land and property rights are divided among multiple actors. These transactions represent large, expensive, and relatively untested experiments in integrating conservation, sustainable forest management, and economic development. As such, there is a need for critical assessment in order to evaluate outcomes, manage adaptively, and inform the design of future transactions. We reviewed existing definitions of sustainable forest management, as well as case studies of working forests, to evaluate how ecological and socioeconomic indicators are incorporated in forest management and policy. We also undertook an in-depth case study of a working forest transaction involving the former Finch Pruyn lands in New York State, to explore how this particular arrangement integrates international, regional, and local sustainability goals. We found that our current ability to learn from past experience with working forests is severely limited by a lack of integrated, iterative monitoring data. Monitoring programs tend to be short-term and stymied by small budgets, high staff turnover, and the complexity of the underlying socio-ecological systems. We also found that management objectives for the Finch Pruyn working forest reflect ecological criteria that are consistent with international standards for sustainable forest management, as well as many of the goals described by regional and local actors, such as providing new public recreation opportunities and maintaining some level of forest- related employment. Specific goals related to supporting local economic development were less well reflected in management objectives. Such goals, however, are arguably beyond the scope of a single land deal. In general, we found that working forest transactions have the potential to achieve multiple conservation and sustainability goals, as well as helping to reconcile long-held disputes over forest land management. However, our current ability to assess outcomes is limited by the relatively recent emergence of this strategy and a lack of empirical evidence, particularly related to socioeconomic outcomes. The lack of evidence could exacerbate existing disputes about the relationship between forest land use, ecological integrity, and socioeconomic well-being. Given the inherent complexity of the issues surrounding working forests, we recommend integrated ecological and socioeconomic monitoring to support adaptive management and to build on existing networks between conservation groups, environmental agencies, forest landowners, and local communities. By bringing critical attention to these large, complex experiments in forest conservation and sustainable management, we hope to inform efforts to simultaneously protect ecological integrity and meet the needs of current and future generations.

Integrating Ecological and Socioeconomic Monitoring of Working Forests

by Rachel Neugarten

Neugarten, R. A., S. A. Wolf, R. C. Stedman, and T. H. Tear. 2011. Integrating Ecological and Socioeconomic Monitoring of Working Forests. BioScience 61:631–637.

Large-scale sell-offs of industrial timberlands in the United States have prompted public and private investments in a... more Large-scale sell-offs of industrial timberlands in the United States have prompted public and private investments in a new class of “working forest” land deals, notable for their large size and complex divisions of property rights. These transactions have been pitched as “win-win-win” deals that provide social, economic, and ecological benefits. Despite hundreds of millions of dollars invested in these transactions, we found a paucity of evidence that their supposed benefits are being realized. Monitoring programs necessary to gather such evidence tend to be underfunded, short term, and focused on a limited set of indicators. The few projects with more comprehensive monitoring programs had long-term funding sources, formal mechanisms for incorporating data into subsequent management decisions, and combined multidisciplinary monitoring techniques. We propose that a relatively modest allocation of funds to monitoring could help assess—and hopefully improve—the effectiveness of current and future transactions, to see if the promise of “win-win-win” is actually delivered.

Spatio-temporal patterns of Holocene environmental change in southern Sicily

by Paul Henne

Palaeogeography, Palaeoclimatology, Palaeoecology, In Press
Authors: Camilla Calò, Paul D. Henne, B. Brandon Curry, Michel Magny, Elisa Vescovi, Tommaso La Mantia, Salvatore Pasta, Boris Vannière, Willy Tinner

Few examples of natural forest remain near the Mediterranean coast. Therefore, it is difficult to study how coastal... more Few examples of natural forest remain near the Mediterranean coast. Therefore, it is difficult to study how coastal forests respond to climatic change or their resilience to human impact. We developed a new sedimentary record of Holocene vegetation and fire history at Lago Preola, a coastal lake in southwestern Sicily (Italy). In order to verify the existence of forest at large scale on the coast, we compare pollen from Lago Preola, a medium-sized lake (33 ha), to Gorgo Basso, a small lake (3 ha) located nearby with the aim of separating local from extra-local vegetation dynamics through time using pollen percentages and influx. We then compare Lago Preola pollen to the record from Biviere di Gela, a large lagoon (120 ha) situated 160 km to the east in southern Sicily, to examine differences in vegetation dynamics between the two coastal areas during the Holocene. Lake-level reconstructions and ostracode analyses from Lago Preola provide vegetation-independent evidence of climate change, and help to disentangle human and climatic impacts on vegetation. Pollen data indicate Pistacia-dominated shrublands replaced open grasslands in the region surrounding Lago Preola by 9500 cal yr BP. This change coincided with rising lake levels and the development of an ostracode fauna typical of fresh waters. Evergreen forest dominated by Quercus ilex and Olea europaea started to expand by 7000 cal BP and consolidated at 6500 cal yr BP, when lake levels were near their Holocene high. Similarities between pollen from Lago Preola and Gorgo Basso demonstrate that forest was the dominant vegetation type in coastal Sicily during the middle Holocene at both regional and local scales, and even developed in the drier climatic setting around Biviere di Gela. Lake levels fell at Lago Preola after 7000 cal yr BP, with a strong decline accompanied by increasing salinity after 4500 cal yr BP. However, no transition in vegetation matched these inferred hydrological changes. Instead, forests persisted in the surrounding region until 2200 cal BP when human disturbance intensified. We propose that different climatic factors control lake levels and vegetation in coastal Mediterranean ecosystems. Whereas lake levels are most sensitive to the abundance of winter precipitation, coastal forests depend on spring precipitation and are limited by the length of summer drought. Moisture availability remained suitable for evergreen forests in coastal Sicily during the late Holocene, and humans, not a drier climate drove the regional forest decline.

Modeling annual production and carbon fluxes of a large managed temperate forest using forest inventories, satellite data and field measurements

by hendrik davi

We evaluated annual productivity and carbon fluxes over the Fontainebleau forest, a large heterogeneous forest region... more We evaluated annual productivity and carbon fluxes over the Fontainebleau forest, a large heterogeneous forest region of 17,000 ha, in terms of species composition, canopy structure, stand age, soil type and water and mineral resources. The model is a physiological process-based forest ecosystem model coupled with an allocation model and a soil model. The simulations were done stand by stand, i.e., 2992 forest management units of simulation. Some input parameters that are spatially variable and to which the model is sensitive were calculated for each stand from forest inventory attributes, a network of 8800 soil pits, satellite data and field measurements. These parameters are: (1) vegetation attributes: species, age, height, maximal leaf area index of the year, aboveground biomass and foliar nitrogen content; and (2) soil attributes: available soil water capacity, soil depth and soil carbon content. Main outputs of the simulations are wood production and carbon fluxes on a daily to yearly basis. Results showed that the forest is a carbon sink, with a net ecosystem exchange of 371 g C m−2 year−1. Net primary productivity is estimated at 630 g C m−2 year−1 over the entire forest. Reasonably good agreement was found between simulated trunk relative growth rate (2.74%) and regional production estimated from the National Forest Inventory (IFN) (2.52%), as well as between simulated and measured annual wood production at the forest scale (about 71,000 and 68,000 m3 year−1, respectively). Results are discussed species by species.

Calibration and validation of hyperspectral indices for the estimation of broadleaved forest leaf chlorophyll content, leaf mass per area, leaf area index and leaf canopy …

by hendrik davi

This article aims at finding efficient hyperspectral indices for the estimation of forest sun leaf chlorophyll content... more This article aims at finding efficient hyperspectral indices for the estimation of forest sun leaf chlorophyll content (CHL, µg cmleaf− 2), sun leaf mass per area (LMA, gdry matter mleaf− 2), canopy leaf area index (LAI, m2leaf msoil− 2) and leaf canopy biomass (Bleaf, gdry matter msoil− 2). These parameters are useful inputs for forest ecosystem simulations at landscape scale. The method is based on the determination of the best vegetation indices (index form and wavelengths) using the radiative transfer model PROSAIL (formed by the newly-calibrated leaf reflectance model PROSPECT coupled with the multi-layer version of the canopy radiative transfer model SAIL). The results are tested on experimental measurements at both leaf and canopy scales. At the leaf scale, it is possible to estimate CHL with high precision using a two wavelength vegetation index after a simulation based calibration. At the leaf scale, the LMA is more difficult to estimate with indices. At the canopy scale, efficient indices were determined on a generic simulated database to estimate CHL, LMA, LAI and Bleaf in a general way. These indices were then applied to two Hyperion images (50 plots) on the Fontainebleau and Fougères forests and portable spectroradiometer measurements. They showed good results with an RMSE of 8.2 µg cm− 2 for CHL, 9.1 g m− 2 for LMA, 1.7 m2 m− 2 for LAI and 50.6 g m− 2 for Bleaf. However, at the canopy scale, even if the wavelengths of the calibrated indices were accurately determined with the simulated database, the regressions between the indices and the biophysical characteristics still had to be calibrated on measurements. At the canopy scale, the best indices were: for leaf chlorophyll content: NDchl = (ρ925 − ρ710)/(ρ925 + ρ710), for leaf mass per area: NDLMA = (ρ2260 − ρ1490)/(ρ2260 + ρ1490), for leaf area index: DLAI = ρ1725 − ρ970, and for canopy leaf biomass: NDBleaf = (ρ2160 − ρ1540)/(ρ2160 + ρ1540).

Litterfall dynamics in an overcrowded mangrove Kandelia obovata (S., L.) Yong stand over five year

by Sahadev Sharma

Korcak dimension as a novel indicator of landscape fragmentation and re-forestation

by Markus Neteler

Imre, A.R., Cseh, D., Neteler, M., Rocchini, D. (2011). Korcak dimension as a novel indicator of landscape fragmentation and re-forestation. Ecological Indicators, 11: 1134–1138

In spatial ecology, habitat fragmentation is an important problem since its increase may create habitat remnants... more In spatial ecology, habitat fragmentation is an important problem since its increase may create habitat remnants threatening species survival. There are several descriptors to characterize the processes leading to fragmentation. Some of them are model-dependent, while others suffer from the combined error of the perimeter and area measurements of the fragmented patches. In this article – using a theoretical model and a worked example – we would like to show that the Korcak-plot (and the corresponding fractal dimension, the Korcak-dimension) is not only a proper way to describe patchiness, but also applicable to detect secondary processes, like re-forestation, following the primary fragmentation.

US Environmental History and Social Ecology Talk given to Yale University School of Environmental Studies and Forestry 13th April 2011

by Damian White

Talk I gave to Yale University School of Environmental Studies and Forestry, April 13th, 2011 about Murray Bookchin and US environmental history.

Tree regeneration responses to Chusquea montana bamboo die-off in a subalpine Nothofagus forest in the southern Andes

by Andrés Holz

Variation in recruitment and early demography in Pinus rigida following crown fire in the pine barrens of Long Island, New York

by Gordon Fox

Sources of variation in growth, form, and survival in dwarf and normal-stature pitch pines (Pinus rigida, Pinaceae) in long-term transplant experiments

by Gordon Fox