Modelling Determinants of Tree Planting and Retention on Farm for Improvement of Forest Cover in Central Kenya

Farm forestry has proved to be an important enterprise for small- and large-scale farmers worldwide. It has the potential of improving forest/tree cover across the globe. In Kenya, the forest cover is less than 2%. The country envisions achieving 10% forest cover over the next decade through promotion of farm forestry. However, the decision to plant trees on farmers’ land could be difficult. The study aimed to analyze the determinants of tree retention on farm for improvement of forest cover. Stratified and simple random sampling techniques were used in selecting 209 farmers. The results showed that sites, land size, age, education level, monthly income, tree management, extension services, availability of markets, harvesting regulation, and aesthetic and environmental motivation were significant determinants of tree retention. In particular, the chances of farmers who had gained technical skills in tree management were about 2.2 times higher to retain trees as compared to those who had not acquired such skills. Similarly, chances of farmers motivated to plant trees for environmental conservation were about 3.5 times higher to retain trees as compared to the group of farmers planting trees as a source of livelihood. These determinants would be instrumental in strengthening the current policies and reforms in forestry and agricultural sectors to enable Kenya to achieve 10% of forest cover.

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Assessing the Importance of Tree Cover Threshold for Forest Cover Mapping Derived from Global Forest Cover in Myanmar

Forests ◽

10.3390/f10121062 ◽

2019 ◽

Vol 10 (12) ◽

pp. 1062 ◽

Cited By ~ 2

Author(s):

Kay Khaing Lwin ◽

Tetsuji Ota ◽

Katsuto Shimizu ◽

Nobuya Mizoue

Keyword(s):

Large Scale ◽

Forest Cover ◽

Remote Sensing Data ◽

Tree Cover ◽

Tropical Rainforests ◽

Forest Change ◽

Tropical Regions ◽

Ecological Zones ◽

Optimal Tree ◽

Forest Cover Mapping

Comprehensive forest cover mapping is essential for making policy and management decisions. However, creating a forest cover map from raw remote sensing data is a barrier for many users. Here, we investigated the effects of different tree cover thresholds on the accuracy of forest cover maps derived from the Global Forest Change Dataset (GFCD) across different ecological zones in a country-scale evaluation of Myanmar. To understand the effect of different thresholds on map accuracy, nine forest cover maps having thresholds ranging from 10% to 90% were created from the GFCD. The accuracy of the forest cover maps within each ecological zone and at the national scale was assessed. The overall accuracies of ecological zones other than tropical rainforest were highest when the threshold for tree cover was less than 50%. The appropriate threshold for tropical rainforests was 80%. Therefore, different optimal tree cover thresholds were required to achieve the highest overall accuracy depending on ecological zones. However, in the unique case of Myanmar, we were able to determine the threshold across the whole country. We concluded that the threshold for tree cover for creating a forest cover map should be determined according to the areal ratio of ecological zones determined from large-scale monitoring. Our results are applicable to tropical regions having similar ecological zones.

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Ecologies of the colonial present: Pathological forestry from the taux de boisement to civilized plantations

Environment and Planning E Nature and Space ◽

10.1177/2514848618812029 ◽

2018 ◽

Vol 1 (4) ◽

pp. 447-469 ◽

Cited By ~ 4

Author(s):

Diana K Davis ◽

Paul Robbins

Keyword(s):

Environmental Governance ◽

Forest Cover ◽

Forest Tree ◽

Tree Planting ◽

Tree Cover ◽

British India ◽

Early 19Th Century ◽

Forest Policies ◽

French Colonial ◽

The Government

Tree-planting has long been an obsession of postcolonial environmental governance. Never innocent of its imperial history, the practice persists in global regimes of forestry today. For over two centuries, afforestation has been viewed as a panacea for a variety of ills including civilizational decline, diminished precipitation, warming temperatures, soil erosion, and decreasing biodiversity. As a result, tree plantations, despite their demonstrated failings in many environments, have flourished as an art of environmental governance that we term arboreal biopolitics. We trace some of the origins and importance of the taux de boisement in such plantation efforts, typically understood as a percentage of “appropriately” wooded land within a territory. Likely first developed in France by the early 19th century, this notion was operationalized in colonial territories assumed to be massively deforested. Targets of 30–33% forest cover, the minimum assumed for European civilization, were built into French forest training and policy and exported globally. Indeed, we demonstrate here that these French colonial policies and influences were as significant in many regions as those of better documented German forestry traditions, especially in African colonial territories and in British India. We further analyze the implications of these policies, and the degree to which the concept of a taux de boisement appears to have traveled to colonial forestry in India, further shaping forest policies of the postindependence era. We provide the example of the “National Mission for a Green India,” an effort by the Government of India to increase forest/tree cover by 5 million hectares and improve quality of forest cover on another 5 million hectares of forest/nonforest lands. Ostensibly aimed at improving forest-based livelihoods, the initiative has all the qualities of past forestry efforts in India, which have historically performed a reverse role: disinheriting forest-rooted populations. Colonial forestry, we therefore conclude, continues to haunt contemporary policy, contributing pathological ecologies, especially in the drylands, often with pernicious effects on local people.

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Progressive Midlatitude Afforestation: Impacts on Clouds, Global Energy Transport, and Precipitation

Journal of Climate ◽

10.1175/jcli-d-15-0748.1 ◽

2016 ◽

Vol 29 (15) ◽

pp. 5561-5573 ◽

Cited By ~ 18

Author(s):

Marysa M. Laguë ◽

Abigail L. S. Swann

Keyword(s):

Vegetation Cover ◽

Land Surface ◽

Large Scale ◽

Forest Cover ◽

Energy Transport ◽

Climate Impacts ◽

Heat Fluxes ◽

Tree Cover ◽

Climate Response ◽

Cloud Feedbacks

Abstract Vegetation influences the atmosphere in complex and nonlinear ways, such that large-scale changes in vegetation cover can drive changes in climate on both local and global scales. Large-scale land surface changes have been shown to introduce excess energy to one hemisphere, causing a shift in atmospheric circulation on a global scale. However, past work has not quantified how the climate response scales with the area of vegetation. Here, the response of climate to linearly increasing the area of forest cover in the northern midlatitudes is systematically evaluated. This study shows that the magnitude of afforestation of the northern midlatitudes determines the local climate response in a nonlinear fashion, and the authors identify a threshold in vegetation-induced cloud feedbacks—a concept not previously addressed by large-scale vegetation manipulation experiments. Small increases in tree cover drive compensating cloud feedbacks, while latent heat fluxes reach a threshold after sufficiently large increases in tree cover, causing the troposphere to warm and dry, subsequently reducing cloud cover. Increased absorption of solar radiation at the surface is driven by both surface albedo changes and cloud feedbacks. This study shows how atmospheric cross-equatorial energy transport changes as the area of afforestation is incrementally increased. The results highlight the importance of considering both local and remote climate effects of large-scale vegetation change and explore the scaling relationship between changes in vegetation cover and resulting climate impacts.

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Classifying Chimpanzee (Pan troglodytes) Landscapes Across Large-Scale Environmental Gradients in Africa

International Journal of Primatology ◽

10.1007/s10764-020-00164-5 ◽

2020 ◽

Vol 41 (6) ◽

pp. 800-821 ◽

Cited By ~ 6

Author(s):

Kelly L. van Leeuwen ◽

Ross A. Hill ◽

Amanda H. Korstjens

Keyword(s):

Pan Troglodytes ◽

Environmental Variables ◽

Large Scale ◽

Forest Cover ◽

Environmental Gradients ◽

Environmental Data ◽

Tree Cover ◽

Precipitation Seasonality ◽

Forest Mosaic ◽

Study Sites

AbstractPrimates are sometimes categorized in terms of their habitat. Although such categorization can be oversimplistic, there are scientific benefits from the clarity and consistency that habitat categorization can bring. Chimpanzees (Pan troglodytes) inhabit various environments, but researchers often refer to “forest” or “savanna” chimpanzees. Despite the wide use of this forest–savanna distinction, clear definitions of these landscapes for chimpanzees, based on environmental variables at study sites or determined in relation to existing bioclimatic classifications, are lacking. The robustness of the forest–savanna distinction thus remains to be assessed. We review 43 chimpanzee study sites to assess how the landscape classifications of researchers fit with the environmental characteristics of study sites and with three bioclimatic classifications. We use scatterplots and principal components analysis to assess the distribution of chimpanzee field sites along gradients of environmental variables (temperature, rainfall, precipitation seasonality, forest cover, and satellite-derived Hansen tree cover). This revealed an environmental continuum of chimpanzee study sites from savanna to dense forest, with a rarely acknowledged forest mosaic category in between, but with no natural separation into these three classes and inconsistencies with the bioclimatic classifications assessed. The current forest–savanna dichotomy therefore masks a progression of environmental adaptation for chimpanzees, and we propose that recognizing an additional, intermediate “forest mosaic” category is more meaningful than focusing on the ends of this environmental gradient only. Future studies should acknowledge this habitat continuum, place their study sites on the forest–savanna gradient, and include detailed environmental data to support further attempts at quantification.

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Rebuilding Tree Cover in Deforested Cocoa Landscapes in Côte d’Ivoire: Factors Affecting the Choice of Species Planted

Forests ◽

10.3390/f12020198 ◽

2021 ◽

Vol 12 (2) ◽

pp. 198

Author(s):

Alain R. Atangana ◽

Juvenal Zahoui Gnangoh ◽

Allegra Kouassi Yao ◽

Thomas d’Aquin Kouakou ◽

Anatole Mian Ndri Nda ◽

...

Keyword(s):

Cote D'ivoire ◽

Tree Species ◽

Forest Cover ◽

Côte D’Ivoire ◽

Tree Planting ◽

Tree Cover ◽

Cote D’Ivoire ◽

Côte D'ivoire ◽

Cocoa Production ◽

Expected Benefits

Intensive cocoa production in Côte d’Ivoire, the world’s leading cocoa producer, has grown at the expense of forest cover. To reverse this trend, the country has adopted a “zero deforestation” agricultural policy and committed to rehabilitating its forest cover through the planting of high-value tree species in cocoa landscapes using a participatory approach. However, little is known regarding the factors influencing farmers’ introduction of high-value tree species to cocoa landscapes. We tested the hypothesis that ten previously reported factors to influence agroforestry system adoption to predict the number and choice of tree species that farmers introduce to cocoa farms. We interviewed 683 households in the cocoa-producing zone of Côte d’Ivoire and counted tree species on their cocoa farms. On average, two tree species were recorded per surveyed farm. Generalized Poisson regression models revealed that, in the cocoa production area, experience in tree planting and expected benefits, including income and food, influence tree species introduction through planting or “retention” when clearing land for cocoa establishment. The age of the farmer also influenced (p = 0.017) farmers’ tree species planting on cocoa farms. Fewer tree species were introduced into current intensive cocoa-production areas than in “old cocoa-loops” and forested areas. The number of tree species introduced to cocoa farms increased with expected benefits and experience in tree planting. The number of planted tree species also increased with farmers’ age. Tree species were mostly selected for the provision of shade to cocoa, production of useful tree products (38%), and income from the sale of these products (7%). Fruit tree species were the most planted, while timber tree species were mostly spared when clearing land for cocoa production.

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ON-FARM FORESTRY DEVELOPMENT OPTIONS FOR NORTHLAND

Proceedings of the New Zealand Grassland Association ◽

10.33584/jnzg.1986.47.1762 ◽

1986 ◽

pp. 27-32

Author(s):

J.S. Clark

Keyword(s):

Joint Ventures ◽

Low Fertility ◽

High Fertility ◽

Financial Returns ◽

Farm Forestry ◽

Hill Country ◽

Financial Position ◽

On Farm

Agroforests and woodlots offer Northland hill country farmers investment and diversification opportunities. Agroforests have less effect on the "whole farm" financial position than woodlots, especially where a progressive planting regime is adopted and where no further borrowing is required. Establishment and tending costs for agro-forests are lower, and returns come much sooner. The proven opportunity for continued grazing under trees established in this manner, apart from a short post-planting period, further enhances the agroforesty option. Even where there is reluctance on a farmer's part to plant trees on high fertility land, the expected financial returns from agroforests on low and medium fertility land will increase the overall long-term profitability and flexibility of the whole farming operation. Woodlots may be more appropriate on low fertility areas where weed reversion is likely. Joint ventures may be worth considering where farm finances are a limited factor. Keywords: On-farm forestry development, Northland hill country, agroforestry, woodlots, diversification, joint ventures, progressive planting regimes, grazing availability.

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Evaluating Forest Cover and Fragmentation in Costa Rica with a Corrected Global Tree Cover Map

Remote Sensing ◽

10.3390/rs12193226 ◽

2020 ◽

Vol 12 (19) ◽

pp. 3226

Author(s):

Daniel Cunningham ◽

Paul Cunningham ◽

Matthew E. Fagan

Keyword(s):

Costa Rica ◽

Forest Cover ◽

Agricultural Land ◽

Forest Area ◽

Tree Cover ◽

Agricultural Crop ◽

Forest Change ◽

Alos Palsar ◽

Tropical Regions ◽

The Impact

Global tree cover products face challenges in accurately predicting tree cover across biophysical gradients, such as precipitation or agricultural cover. To generate a natural forest cover map for Costa Rica, biases in tree cover estimation in the most widely used tree cover product (the Global Forest Change product (GFC) were quantified and corrected, and the impact of map biases on estimates of forest cover and fragmentation was examined. First, a forest reference dataset was developed to examine how the difference between reference and GFC-predicted tree cover estimates varied along gradients of precipitation and elevation, and nonlinear statistical models were fit to predict the bias. Next, an agricultural land cover map was generated by classifying Landsat and ALOS PalSAR imagery (overall accuracy of 97%) to allow removing six common agricultural crops from estimates of tree cover. Finally, the GFC product was corrected through an integrated process using the nonlinear predictions of precipitation and elevation biases and the agricultural crop map as inputs. The accuracy of tree cover prediction increased by ≈29% over the original global forest change product (the R2 rose from 0.416 to 0.538). Using an optimized 89% tree cover threshold to create a forest/nonforest map, we found that fragmentation declined and core forest area and connectivity increased in the corrected forest cover map, especially in dry tropical forests, protected areas, and designated habitat corridors. By contrast, the core forest area decreased locally where agricultural fields were removed from estimates of natural tree cover. This research demonstrates a simple, transferable methodology to correct for observed biases in the Global Forest Change product. The use of uncorrected tree cover products may markedly over- or underestimate forest cover and fragmentation, especially in tropical regions with low precipitation, significant topography, and/or perennial agricultural production.

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India’s Commitments to Increase Tree and Forest Cover: Consequences for Water Supply and Agriculture Production within the Central Indian Highlands

Water ◽

10.3390/w13070959 ◽

2021 ◽

Vol 13 (7) ◽

pp. 959

Author(s):

Benjamin Clark ◽

Ruth DeFries ◽

Jagdish Krishnaswamy

Keyword(s):

Groundwater Recharge ◽

Forest Cover ◽

Hydrological Modeling ◽

Monsoon Season ◽

Forest Policy ◽

Central India ◽

Field Measurements ◽

Tree Cover ◽

Policy Goals ◽

The Impact

As part of its nationally determined contributions as well as national forest policy goals, India plans to boost tree cover to 33% of its land area. Land currently under other uses will require tree-plantations or reforestation to achieve this goal. This paper examines the effects of converting cropland to tree or forest cover in the Central India Highlands (CIH). The paper examines the impact of increased forest cover on groundwater infiltration and recharge, which are essential for sustainable Rabi (winter, non-monsoon) season irrigation and agricultural production. Field measurements of saturated hydraulic conductivity (Kfs) linked to hydrological modeling estimate increased forest cover impact on the CIH hydrology. Kfs tests in 118 sites demonstrate a significant land cover effect, with forest cover having a higher Kfs of 20.2 mm hr−1 than croplands (6.7mm hr−1). The spatial processes in hydrology (SPHY) model simulated forest cover from 2% to 75% and showed that each basin reacts differently, depending on the amount of agriculture under paddy. Paddy agriculture can compensate for low infiltration through increased depression storage, allowing for continuous infiltration and groundwater recharge. Expanding forest cover to 33% in the CIH would reduce groundwater recharge by 7.94 mm (−1%) when converting the average cropland and increase it by 15.38 mm (3%) if reforestation is conducted on non-paddy agriculture. Intermediate forest cover shows however shows potential for increase in net benefits.

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Synthesizing published knowledge of boreal forest cover change for large-scale landscape dynamics modelling

The Forestry Chronicle ◽

10.5558/tfc79132-1 ◽

2003 ◽

Vol 79 (1) ◽

pp. 132-146 ◽

Cited By ~ 3

Author(s):

Dennis Yemshanov ◽

Ajith H Perera

Keyword(s):

Boreal Forest ◽

Large Scale ◽

Forest Canopy ◽

Forest Cover ◽

Forest Succession ◽

Simulation Models ◽

Limiting Factors ◽

Sources Of Information ◽

Forest Cover Change ◽

Discrete State

We reviewed the published knowledge on forest succession in the North American boreal biome for its applicability in modelling forest cover change over large extents. At broader scales, forest succession can be viewed as forest cover change over time. Quantitative case studies of forest succession in peer-reviewed literature are reliable sources of information about changes in forest canopy composition. We reviewed the following aspects of forest succession in literature: disturbances; pathways of post-disturbance forest cover change; timing of successional steps; probabilities of post-disturbance forest cover change, and effects of geographic location and ecological site conditions on forest cover change. The results from studies in the literature, which were mostly based on sample plot observations, appeared to be sufficient to describe boreal forest cover change as a generalized discrete-state transition process, with the discrete states denoted by tree species dominance. In this paper, we outline an approach for incorporating published knowledge on forest succession into stochastic simulation models of boreal forest cover change in a standardized manner. We found that the lack of details in the literature on long-term forest succession, particularly on the influence of pre-disturbance forest cover composition, may be limiting factors in parameterizing simulation models. We suggest that the simulation models based on published information can provide a good foundation as null models, which can be further calibrated as detailed quantitative information on forest cover change becomes available. Key words: probabilistic model, transition matrix, boreal biome, landscape ecology

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Effects of Windthrows on Forest Cover, Tree Growth and Soil Characteristics in Drought-Prone Pine Plantations

Forests ◽

10.3390/f12070817 ◽

2021 ◽

Vol 12 (7) ◽

pp. 817

Author(s):

Jesús Julio Camarero ◽

Michele Colangelo ◽

Antonio Gazol ◽

Manuel Pizarro ◽

Cristina Valeriano ◽

...

Keyword(s):

Vegetation Index ◽

Forest Cover ◽

Normalized Difference Vegetation Index ◽

Pinus Halepensis ◽

Soil Characteristics ◽

Tree Cover ◽

Mediterranean Forests ◽

Soil Microbial Community Structure ◽

Soil Features ◽

Disturbance Intensity

Windstorms are forest disturbances which generate canopy gaps. However, their effects on Mediterranean forests are understudied. To fill that research gap, changes in tree, cover, growth and soil features in Pinus halepensis and Pinus sylvestris plantations affected by windthrows were quantified. In each plantation, trees and soils in closed-canopy stands and gaps created by the windthrow were sampled. Changes in tree cover and radial growth were assessed by using the Normalized Difference Vegetation Index (NDVI) and dendrochronology, respectively. Soil features including texture, nutrients concentration and soil microbial community structure were also analyzed. Windthrows reduced tree cover and enhanced growth, particularly in the P. halepensis site, which was probably more severely impacted. Soil characteristics were also more altered by the windthrow in this site: the clay percentage increased in gaps, whereas K and Mg concentrations decreased. The biomass of Gram positive bacteria and actinomycetes increased in gaps, but the biomass of Gram negative bacteria and fungi decreased. Soil gaps became less fertile and dominated by bacteria after the windthrow in the P. halepensis site. We emphasize the relevance of considering post-disturbance time recovery and disturbance intensity to assess forest resilience within a multi-scale approach.

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