Land use affects the soil C sequestration in alpine environment, NE Italy

Soil carbon sequestration is strongly affected by soil properties, climate, and anthropogenic activities. Assessing these drivers is key to understanding the effect of land use on soil organic matter stabilization. We evaluated land use and soil depth influencing patterns of soil organic matter stabilization in three types of soil profiles located under the same pedogenetic matrix and alpine conditions but with different vegetation cover. The stock in soil organic carbon in the mean 0–20 cm layer increased from prairie (31.9 t ha−1) to prairie in natural reforestation (42 t ha−1) to forest (120 t ha−1), corresponding to increments of 1.3-fold prairie, for prairie in natural reforestation, and of 3.8-fold prairie for forest. The forest showed the highest humic carbon (21.7 g kg−1), which was 2.8 times greater than the prairie in natural reforestation and 4 times higher than the prairie. 13C-NMR spectroscopic measurements suggested a different C pattern. The prairie in natural reforestation and the prairie were characterized by a higher content in O,N-alkyl C with respect to the forest. Alkyl C and aromatic C in the prairie in natural reforestation and prairie did not show relevant differences while they decreased with respect to the forest. Carboxyl and phenolic C groups were markedly higher in forest and prairie than prairie in natural reforestation. Alkyl C, carboxyl C, and phenolic C prevailed in the Ah horizons whereas aromatic C and O,N-alkyl C were dominant in the B horizons. Overall, the marked distribution of O,N-alkyl C and alkyl C in humic substances (HS) indicates a low degree of humification. Nevertheless, in forest, the relatively high presence of aromatic C designated HS endowed with a relatively high humification degree. Thus, our results might suggest that in the alpine environment of NE Italy differences in soil organic matter (SOM) stocks and characteristics are affected by land use and anthropic activities

The Evolution of Reforestation in Brazil

This paper analyzes the evolution of reforestation in Brazil and makes an evaluation of federal government policies used to stimulate that activity. Despite the huge increase of reforestation areas in Brazil since the 1970s, what put up Brazil as the sixth large country with reforested areas, a scarcity of roundwood from reforested areas is happing in that country during the first decade of the 21st century. Federal government implemented three programs to foster the reforestation in Brazil during the 1960s, 1970s and 1980s. However, nothing was implemented during the 1990s, when demand of roundwood increased, but not its production. This paper analyzes those programs, using a traditional cost-benefit approach. The results of that evaluation are used to suggest new federal government policies to foster the enlargement of reforestation in segments where price mechanism has not working well.

Evaluation of artificial reforestation efforts in the ribbon forest zone of Altai Krai

The ribbon forest zone of Altai Krai is located in the Kulunda Steppe and on the Priobskoye Plateau. The climate of this region is characterized by extreme aridity. Due to the harsh climate and the importance of the ribbon forests for the environmental sustainability of the region, artificial reforestation is an integral part of the regional forest management. Forest stands of artificial origin currently occupy a large area within the ribbon forest zone, as evidenced by forest inventory data. However, due to the fact that surveys are not conducted simultaneously on the whole territory of Altai Krai, and that they miss some of the forest management units, forest inventory data do not provide an up-to-date assessment of artificial reforestation efforts. Our project attempted to update the existing data of forest resource assessments and evaluate the results of artificial reforestation efforts in the ribbon forest zone of Altai Krai. This article presents data on the distribution of the artificially reforested area by predominant species and type of growing conditions, and the distribution of the growing stock of the artificially established stands by age and type of forest growing conditions. © 2019 IOP Publishing Ltd. All rights reserved

Giving credit to reforestation for water quality benefits.

While there is a general belief that reforesting marginal, often unprofitable, croplands can result in water quality benefits, to date there have been very few studies that have attempted to quantify the magnitude of the reductions in nutrient (N and P) and sediment export. In order to determine the magnitude of a credit for water quality trading, there is a need to develop quantitative approaches to estimate the benefits from forest planting in terms of load reductions. Here we first evaluate the availability of marginal croplands (i.e. those with low infiltration capacity and high slopes) within a large section of the Ohio River Basin (ORB) to assess the magnitude of the land that could be reforested. Next, we employ the Nutrient Tracking Tool (NTT) to study the reduction in N, P and sediment losses from converting corn or corn/soy rotations to forested lands, first in a case study and then for a large region within the ORB. We find that after reforestation, N losses can decrease by 40 to 80 kg/ha-yr (95-97% reduction), while P losses decrease by 1 to 4 kg/ha-yr (96-99% reduction). There is a significant influence of local conditions (soils, previous crop management practices, meteorology), which can be considered with NTT and must be taken into consideration for specific projects. There is also considerable interannual and monthly variability, which highlights the need to take the longer view into account in nutrient credit considerations for water quality trading, as well as in monitoring programs. Overall, there is the potential for avoiding 60 million kg N and 2 million kg P from reaching the streams and rivers of the northern ORB as a result of conversion of marginal farmland to tree planting, which is on the order of 12% decrease for TN and 5% for TP, for the entire basin. Accounting for attenuation, this represents a significant fraction of the goal of the USEPA Gulf of Mexico Hypoxia Task Force to reduce TN and TP reaching the dead zone in the Gulf of Mexico, the second largest dead zone in the world. More broadly, the potential for targeted forest planting to reduce nutrient loading demonstrated in this study suggests further consideration of this approach for managing water quality in waterways throughout the world. The study was conducted using computational models and there is a need to evaluate the results with empirical observations

Forest connectivity restoration through reforestation: an integrated methodology for prioritizing agricultural lands and selecting reforestation species

Forest connectivity restoration is a major goal in natural resource planning. Given the high amount of abandoned cultivated lands, setting efficient methods for the reforestation of agricultural lands offers a good opportunity to face this issue. However, reforestations must be carefully planned, which poses two main challenges. In first place, to determine those agricultural lands that, once reforested, would meet more effectively the planning goals. As a further step, in order to grant the success of the activity, it is fairly advisable to select those tree species that are more adapted to each particular environment. Here we intend to give response to both requirements by proposing a sequential and integrated methodology that has been implemented in two Spanish forest districts, which are formed by several landscape types that were previously defined and characterized. Using the software Conefor Sensinode, a powerful tool for quantifying habitat availability that is based on graph theory concepts, we determined the landscapes where forest planning should have connectivity as a major concern and, afterwards, we detected the agricultural patches that would contribute most to enhance connectivity if they were reforested. The subsequent reforestation species assessment was performed within these priority patches. Using penalized logistic regressions we fitted ecological niche models for the Spanish native tree species. The models were trained with species distribution data from the Spanish Forest Map and used climatic and lithological variables as predictors. Model predictions were used to build ordered lists of suitable species for each priority patch. The lists include dominant and non dominant tree species and allow adding biodiversity goals to the reforestation planning. The result of this combined methodology is a map of agricultural patches that would contribute most to uphold forest connectivity if they were reforested and a list of suitable tree species for each patch ordered by occurrence probability. Therefore the proposed methodology may be useful for suitable and efficient forest planning and landscape designing

A direct test of socially desirable responding in contingent valuation interviews

--environmental valuation,contingent valuation method,socially desirable responding,loss aversion,reforestation

Boom and Bust Carbon-Nitrogen Dynamics during Reforestation

Legacies of historical land use strongly shape contemporary ecosystem dynamics. In old-field secondary forests, tree growth embodies a legacy of soil changes affected by previous cultivation. Three patterns of biomass accumulation during reforestation have been hypothesized previously, including monotonic to steady state, non-monotonic with a single peak then decay to steady state, and multiple oscillations around the steady state. In this paper, the conditions leading to the emergence of these patterns is analyzed. Using observations and models, we demonstrate that divergent reforestation patterns can be explained by contrasting time-scales in ecosystem carbon-nitrogen cycles that are influenced by land use legacies. Model analyses characterize non-monotonic plant-soil trajectories as either single peaks or multiple oscillations during an initial transient phase controlled by soil carbon-nitrogen conditions at the time of planting. Oscillations in plant and soil pools appear in modeled systems with rapid tree growth and low initial soil nitrogen, which stimulate nitrogen competition between trees and decomposers and lead the forest into a state of acute nitrogen deficiency. High initial soil nitrogen dampens oscillations, but enhances the magnitude of the tree biomass peak. These model results are supported by data derived from the long-running Calhoun Long-Term Soil-Ecosystem Experiment from 1957 to 2007. Observed carbon and nitrogen pools reveal distinct tree growth and decay phases, coincident with soil nitrogen depletion and partial re-accumulation. Further, contemporary tree biomass loss decreases with the legacy soil C:N ratio. These results support the idea that non-monotonic reforestation trajectories may result from initial transients in the plant-soil system affected by initial conditions derived from soil changes associated with land-use history

Deer and reforestation in the Pacific Northwest

Deer and reforestation interact mainly during regeneration after wildfire or logging. In interior forests, browsing by mule deer often damages conifer seedlings planted on winter or transitional ranges. In the Douglas-fir region, numbers of blacktailed deer increase dramatically after forests are logged or burned, in response to improved forage supplies. Here, browsing on planted stock in clearcuts lowers forest productivity by reducing growth rates and occasionally contributes to plantation failures. Browsing damage can be controlled by fences or cages, but costs are prohibitive. Amelioration of damage by black-tailed deer could be achieved through long-range planning for concurrent deer and timber harvests, with hunting pressure directed to areas where logging promotes more deer. Thus, more deer can be made available to hunters and browsing damage to reforestation lessened. Such programs would require complete cooperation among resource managers and an intensive, well-planned effort to sell them to both customers and critics

Respondent incentives in contingent valuation: The role of reciprocity

--public expenditures,environmental valuation,cost-benefit analysis,contingent valuation method,respondent incentives,reciprocity,reforestation