Natural Forest Cover Research Articles

Nest-site selection by Slender-billed Parakeets in a Chilean agricultural-forest mosaic

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Landscape-level comparison of genetic diversity and differentiation in a small mammal inhabiting different fragmented landscapes of the Brazilian Atlantic Forest

Habitat loss and fragmentation can have detrimental effects on all levels of biodiversity, including genetic variation. Most studies that investigate genetic effects of habitat loss and fragmentation focus on analysing genetic data from a single landscape. However, our understanding of habitat loss effects on landscape-wide patterns of biodiversity would benefit from studies that are based on quantitative comparisons among multiple study landscapes. Here, we use such a landscape-level study design to compare genetic variation in the forest-specialist marsupial Marmosops incanus from four 10,000-hectare Atlantic forest landscapes which differ in the amount of their remaining native forest cover (86, 49, 31, 11 %). Additionally, we used a model selection framework to evaluate the influence of patch characteristics on genetic variation within each landscape. We genotyped 529 individuals with 12 microsatellites to statistically compare estimates of genetic diversity and genetic differentiation in populations inhabiting different forest patches within the landscapes. Our study indicates that before the extinction of the specialist species (here in the 11 % landscape) genetic diversity is significantly reduced in the 31 % landscape, while genetic differentiation is significantly higher in the 49 and 31 % landscapes compared to the 86 % landscape. Results further provide evidence for non-proportional responses of genetic diversity and differentiation to increasing habitat loss, and suggest that local patch isolation impacts gene flow and genetic connectivity only in the 31 % landscape. These results have high relevance for analysing landscape genetic relationships and emphasize the importance of landscape-level study designs for understanding habitat loss effects on all levels of biodiversity.

Understanding species persistence for defining conservation actions: A management landscape for jaguars in the Atlantic Forest

Habitat models constitute useful instruments for understanding species-habitat interactions and can constitute helpful conservation tools. The Upper Paraná Atlantic Forest (UPAF) of South America still holds the world’s southernmost jaguar (Panthera onca) population. Our aims were: (i) to test several a priori hypotheses on the factors affecting jaguar persistence in this region, (ii) to map habitat suitability and identify areas with potentially conflicting habitat conditions, and (iii) to identify priority areas for management and improve the conservation initiatives for jaguars and the UPAF. Following an information-theoretic approach, we used presence records of jaguars and pseudo-absences in generalized linear models. We structured hypotheses into two groups which demand different management actions: land cover and human persecution. The best model of each group was used to develop a two-dimensional habitat model. Jaguar persistence was favoured by current and historical native forest cover, and hindered by human land uses. Protection favoured jaguar presence whereas human accessibility and high human population density had negative effects. The two-dimensional model suggests that <8% (20,670km2) of the landscape represents potential core areas for jaguars (good land-cover characteristics and low human persecution) and 11.8% (32,563km2) stands as potentially attractive sinks where good land-cover conditions conflict with high human persecution. Reduction of human persecution is urgently needed to increase the core areas for jaguars in this region, but improvement of land-cover conditions is important for sustaining the connectivity among jaguar populations that seem to be isolated in different areas of the UPAF.

Curve Numbers for Low-Compaction Steep-Sloped Reclaimed Mine Lands in the Southern Appalachians

In the coal-mining region of the Appalachians, the Forestry Reclamation Approach (FRA) is currently promoted by the U.S. Dept. of Interior, Office of Surface Mining (OSM). FRA’s goal in establishing native forest cover on reclamation sites requires the use of loose spoils rather than traditionally compacted spoils during hillslope reconstruction. Loose spoils improve tree planting survival and enhance overall forest growth. Although FRA has been shown to be successful on low-gradient slopes without excessive runoff leading to erosion, rainfall-runoff relationships have not been studied on steep slopes (>20°) where most surface-mine reclamation typically occurs. A curve number (CN) range representing low-compaction steep-sloped conditions was needed for Appalachian FRA sites. Three active surface-mine sites in East Tennessee were monitored during a 1-year period (June 2009–July 2010) for rainfall (5-min intervals) and runoff hydrology (discharge volume, peak discharge) using a unique Pinson-type collection system. CNs were estimated by the traditional NEH-4 (Part 630) method and two asymptotic, frequency-matching techniques. It was found that an initial abstraction (λ) of 0.2 best fits the data. CNs generated by the NEH-4 method among all three mining sites were not significantly different suggesting common shale-based loose spoils on steep slopes have similar runoff behavior. The CN determined by the asymptotic method provided an estimate with a practical range between 58.5 and 60. This CN range is lower than one would expect from surface-mine sites, suggesting infiltration influenced the measured rainfall-runoff relationships. Further research is needed to investigate the influence of slope and infiltration on runoff behavior at surface-mine sites applying FRA.

Effects of urbanization on Song Sparrow (Melospiza melodia) population connectivity

Urbanization may affect genetic differentiation among animal populations because it converts native vegetation to novel land cover types that can affect population connectivity. The effect of land cover change on genetic differentiation may vary among taxa; mobile birds may be least affected. Regardless, genetic differentiation between populations should be best predicted by measures of distance that incorporate the effect of land cover on movement. We studied the relationship between land cover and genetic differentiation in Song Sparrows (Melospiza melodia) at eighteen sites in the Seattle metropolitan region. We generated a series of hypothetical “resistance surfaces” based on land cover and development age, calculated “resistance distances” between pairs of sampling sites, and related them to pairwise genetic differentiation. Genetic differentiation was best described by a multiple regression model where resistance to gene flow (1) linearly increased with age of development and (2) was greater in high- and medium-density urbanization than in native forest land cover types (R 2 = 0.15; p = 0.003). The single variable with the highest correlation with genetic differentiation was derived from a linear relationship between development age and resistance (R 2 = 0.08; p = 0.007). Our results thus suggested that urban development reduced population connectivity for Song Sparrows. However, the relation of development age to genetic differentiation suggested that equilibrium was not yet reached. Hence, the effects of lost connectivity will increase. Our understanding of the landscape genetics of this recently anthropogenically modified landscape benefited from considering population history.

Simulating Forest Cover Changes of Bannerghatta National Park Based on a CA-Markov Model: A Remote Sensing Approach

Establishment of protected areas (PA) has been one of the leading tools in biodiversity conservation. Globally, these kinds of conservation interventions have given rise to an increase in PAs as well as the need to empirically evaluate the impact of these PAs on forest cover. Few of these empirical evaluations have been geared towards comparison of pre and post policy intervention landscapes. This paper provides a method to empirically evaluate such pre and post policy interventions by using a cellular automata-Markov model. This method is tested using remotely sensed data of Bannerghatta National park (BNP) and its surrounding, which have experienced various national level policy interventions (Indian National Forest Policy of 1988) and rapid land cover change between 1973 and 2007. The model constructs a hypothetical land cover scenario of BNP and its surroundings (1999 and 2007) in the absence of any policy intervention, when in reality there has been a significant potential policy intervention effect. The models predicted a decline in native forest cover and an increase in non forest cover post 1992 whereas the actual observed landscape experienced the reverse trend where after an initial decline from 1973 to 1992, the forest cover in BNP is towards recovery post 1992. Furthermore, the models show a higher deforestation and lower reforestation than the observed deforestation and reforestation patterns for BNP post 1992. Our results not only show the implication of national level policy changes on forest cover but also show the usefulness of our method in evaluating such conservation efforts.

Hydrology, forests and precipitation recycling: a reply to van der Ent et al

DAVID ELLISON*†,MARTYNN.FUTTER‡ and KEVIN BISHOP‡§*Institute for World Economics, Research Centre for Economic and Regional Studies, Hungarian Academy of Sciences, Budapest,Hungary, †Department of Forest Ecology and Management, Swedish University of Agricultural Sciences, Umea˚, Sweden,‡Department of Aquatic Sciences and Assessment, Swedish University of Agricultural Sciences, Uppsala, Sweden, §Department ofEarth Sciences, Uppsala University, Uppsala, Sweden

Pre‐Columbian deforestation as an amplifier of drought in Mesoamerica

Droughts in pre‐Columbian Mesoamerica caused significant societal disruptions during the Late Classic and Post‐Classic Periods. While the primary causes of these droughts are still debated, it has been speculated that they may be linked to extensive deforestation associated with high population densities during these intervals. Here we show that pre‐Columbian deforestation would have biased the climate in Mesoamerica towards a drier mean state, amplifying drought in the region. In climate model simulations using a pre‐Columbian land cover reconstruction, annual precipitation decreases by 5%–15% throughout southern Mexico and the Yucatán compared to simulations using either natural forest cover or forest regrowth associated with population declines after 1500 C.E. These changes are driven primarily by large reductions (10%–20%) in precipitation during the late summer wet season (August–September). When compared to precipitation changes estimated to have occurred during the Maya collapse, our results suggest that deforestation could account for up to sixty percent of the mean drying during this interval. Many regions previously deforested in the pre‐Columbian era are now under dense forest cover, indicating potential future climate impacts should tropical deforestation of these areas accelerate.

Forest cover, socioeconomics, and reported flood frequency in developing countries

In this paper, we analyze the determinants of the number of large floods reported since 1990. Using the same sample of countries as Bradshaw et al. (2007), and, like them, omitting socioeconomic characteristics from the analysis, we found that a reduction in natural forest cover is associated with an increase in the reported count of large floods. This result does not hold in any of three new analyses we perform. First, we expand the sample to include all the developing countries and all countries for which data were available but were omitted in their study. Second, and more importantly, since forest management is just one possible channel through which humans can influence reported flood frequency, we account for other important human–flood interactions. People are typically responsible for deforestation, but they are also responsible for other land use changes (e.g., urbanization), for floodplain and flood emergency management, and for reporting the floods. Thus, in our analysis we account for population, urban population growth, income, and corruption. Third, we exploit the panel nature of the data to control for unobserved country and time heterogeneity. We conclude that not only is the link between forest cover and reported flood frequency at the country level not robust, it also seems to be driven by sample selection and omitted variable bias. The human impact on the reported frequency of large floods at the country level is not through deforestation.

Hybrid poplar yields in Québec: Implications for a sustainable forest zoning management system

In the province of Québec, approximately 12 000 ha of fast-growing poplar plantations are managed by industrials, while small private landowners have planted only 1000 ha. Most of these poplar plantations are established on clearcut forest sites (approx. 11 000 ha). What are the yields of these hybrid poplar plantations? In this article, available yield data are presented and discussed in the context of a sustainable forest zoning management system. In southern Québec, three factors are highly correlated to yield for clones of various parentages: NO3supply rate in riparian soils, elevation (or climate) and soil P availability in abandoned farmland soils. Many Québec forest sites, particularly in the boreal shield ecozone, have acidic soils and harsh climate, with low mineralization rates. They generally cannot fulfill the very high nutrient requirements of hybrid poplars. Within a forest zoning management system, hybrid poplar plantations and agroforestry should be located in priority in southern Québec landscapes, with low remaining natural forest cover, and where intensive agriculture is the dominant land-use. This strategy will increase biodiversity and the provision of ecosystem services. Elsewhere, intensive trembling aspen regeneration silviculture could be a sustainable alternative to forest conversion into hybrid poplar plantations.

Forest cover change in Sri Lanka: The role of small scale farmers

Forest cover in Sri Lanka has decreased rapidly during the last century and only fragments of the once widespread natural forest cover remain. This paper analyzes forest cover change and small scale farmers' relation to natural forests around two protected forest areas in Sri Lanka; Kanneliya Forest Reserve and Knuckles Conservation Forest. Methods used are spatial analysis to observe changes in forest cover from the 1980s until 2010, interviews with small scale farmers and key informants as well as field observations. In Kanneliya Forest Reserve, a decrease in forest cover is observed, particularly due to population increase and expanding tea plantations. In Knuckles Conservation Forest on the other hand, we find an overall increase in forest cover due to expansion of tree plantations, a ban on shifting cultivation and emigration from the area followed by natural forest regeneration. Agriculture is the most common source of income in both study areas and there is a clear link between conversions of forests to agricultural expansion. The profits from agricultural activities are in general insufficient to sustain small scale farmers' needs and the most common alternative source of income is achieved through resources extracted from the forest. Since 2001, demarcation of forest boundaries around the two forest reserves has reduced encroachment and illegal felling of timber. However, this policy has simultaneously threatened the livelihoods of peripheral communities in the forest buffer zones, especially in the investigated villages around Knuckles Conservation Forest. Despite successful attempts to reduce deforestation rates through governmental interventions, further incorporation of local people into the management of forests as stipulated in the current forest policy should be continued.

CARBON FOOTPRINT OF AN ORGANIZATION: A CASE STUDY, FACULTY OF AGRICULTURE, UNIVERSITY OF RUHUNA

In order to identify the organizational impact on global warming, an analysis was carried out using planned CO2 inventory with setting organizational and operational boundary under three scopes, according to GHG protocol. Carbon Footprint was calculated by using emission factors, obtained from 2006 IPCC Guidelines for National Greenhouse Gas Inventories. Most relevant and appropriate emission factors for Sri Lankan conditions were selected by using assumptions to increase the transparency of the study. Results show that total CFP of the Faculty is 418.5 t CO2-e/yr. Average CFP per person in the Faculty is 0.571 tCO2- e/yr. Transportation accounts for highest percentage, 37%, followed by electricity consumption having 27%, handling of farm animals with 22% and waste disposal is 11% of the total CFP. Other sources and activities show small portion of the total, such as stationary combustion sources accounts 2%, water consumption from outside water plants having 1% and rice cultivated area with 0.04%. It is concluded that calculated CFP is low compared to the estimates available worldwide. Net CFP of Faculty may be less than calculated value, as Faculty has further contributed to reduce and offset its CFP through adapting to the eco friendly activities and available natural forest cover with in the Faculty.

Can mixed species stands enhance arthropod diversity in plantation forests?

Tree species composition is a key driver of forest biodiversity, influencing structural components of the environment from soil and litter to vegetation layers and the canopy, and ecosystem processes, such as nutrient cycling. Single species stands, particularly intensively managed monoculture plantations, are typically more homogenous in habitat structure and the biotic communities supported, than mixed stands. Thus, international forest policy increasingly promotes the establishment of mixed stands as an alternative to enhance biodiversity in plantations. Forests represent around 10% of the land area of Ireland, with most being monocultures of non-native conifers. By contrast, natural forest cover, primarily comprised of deciduous species, is just 1%. In recent years there has been an increase in mixed plantations; however, optimum tree species combinations, which aim to promote biodiversity under sustainable forest management, have yet to be established. Arthropods (ground-dwelling spiders and Carabid beetles, and night-flying macrolepidoptera) were examined in twenty mixed and monoculture plantations in Ireland (Norway spruce–oak mix, Norway spruce–Scots pine mix, Norway spruce monoculture). Both oak and Scots pine were secondary mix components, comprising between 15% and 40% of stems. Spiders and Carabid beetles were sampled using pitfall traps during summer 2008 and moths using light traps during summer and autumn 2008 and spring 2009.There was no evidence for an influence of oak or Scots pine on the arthropod fauna when they were a secondary component in a mix. Overall, arthropod communities were similar in species richness, assemblage structure and habitat specialists among the forest types. Furthermore, the mixed stands exhibited similar environmental conditions to monocultures in terms of stand structure, vegetation and litter cover. This suggests that there is limited biodiversity value from an additional canopy species comprising 15–40% of the mix, at least for the taxa and tree species studied here. This has implications for forest policy, where recommendations are often based on the proportion of each mix component, at least in terms of the potential biodiversity value of additional canopy species. Further research is required to determine the proportion at which oak or Scots pine begin to influence the arthropod fauna.

Holocene anthropogenic landscapes in the Balkans: the palaeobotanical evidence from southwestern Bulgaria

Palaeoecological reconstructions from the region of southwestern Bulgaria were used for inferring the human impact on the vegetation and landscape during the last 8 millennia. They are based on data from pollen analyses of lakes and peat-bogs, plant macrofossils, archaeobotanical finds and radiocarbon dating. During the early Holocene, after 7900 cal. b.p. (5950 cal. b.c.) the climate changed to cooler summers, milder winters and higher precipitation resulting in the formation of a coniferous belt dominated by Pinus sp. and Abies alba. These favorable environmental pre-conditions had a positive influence on the Neolithisation of the Balkans after the 8200 cal. b.p. (6250 cal. b.c.) cold event, which caused drought in the Eastern Mediterranean. Direct evidence from wood charcoal records from the Neolithic settlement layers in the study area shows a slight modification of the surrounding woodlands and an increase of the light-demanding components, probably expressed through larger forest border zones and thinning out of the wood stands. The increase in the number of settlements in the valleys of southwestern Bulgaria intensified the human activity visible in the palaeobotanical record from 6950 cal. b.p. (5000 cal. b.c.) onwards. Between ca. 5700–5100 cal. b.p. (3800–3200 cal. b.c.) signs of anthropogenic influence on the vegetation are virtually absent. The intensity of human impact increased notably after 3200 cal. b.p. (1400–1250 cal. b.c., approx. Late Bronze Age), documented by a rise of pollen anthropogenic indicators. The final transformations in the natural forest cover after 2750 cal. b.p. (800 cal. b.c. onset of the Iron Age) marked the reduction of the coniferous forests dominated by Abies alba and Pinus sp. and the expansion of Fagus sylvatica and Picea abies. These vegetation changes are contemporaneous with increase of the palaeofire activities and the next peak of anthropogenic indicators. The changes in the landscape during the Roman period and the medieval period reflect regional environmental features and were forced by the diversification of anthropogenic activity.

Evaluating the suitability of planted forests for African forest monkeys: a case study from Kakamega forest, Kenya

As natural forest cover declines, planted forests have come to occupy an increasing percentage of the earth's surface, yet we know little about their suitability as alternative habitat for wildlife. Although some primate species use planted forests, few studies have compared primate populations in natural and nearby planted forests. From March 2006 to July 2010, we conducted line transect surveys and assessed group sizes and compositions in natural and nearby 60-70 year old mixed indigenous planted forest to determine the densities of diurnal primate species (Colobus guereza, Cercopithecus mitis, C. ascanius) in these two forest types at Isecheno, Kakamega Forest, Kenya. Line transect data were analyzed using the Encounter Rate, Whitesides, and Distance sampling methods, which all provided broadly consistent results. We found that all three diurnal primate species occupy both natural and planted forest at Isecheno. However, group densities of the two Cercopithecus species were 42-46% lower in planted than in natural forest. Colobus guereza achieved comparable group densities in the two forest types, although the species is found in smaller groups, and thus at lower (35%) individual density, in planted than in natural forest. Following a logging episode in the planted forest mid-way through our study, Cercopithecus ascanius group densities fell by 60% while C. mitis and Colobus guereza group densities remained stable over the next two years. Overall, our results suggest that while primate species vary in their response to habitat disturbance, planted forest has the potential to contribute to the conservation of some African monkey species. Even for the relatively flexible taxa in our study, however, 60-70 year old mixed indigenous planted forest failed to support densities comparable to those in nearby natural forest. From the perspective of Kakamega's primates, planted forests may supplement natural forest, but are not an adequate replacement for it.

The Effect of Growth Rate on the Wood Quality of Fast Grown Hardwood Plantation Species in Sri Lanka

In the past when most of the country was covered by natural forests, logs of various natural species flowedinto the market. However, now that natural high canopy forest cover has reduced, and restrictions on fellingand transport of timber, supplies from natural forests are limited. The domestic forest industries are dependenton the supply of wood from sources other than natural forests. Forest plantations play major role in supply oftimber. State forest plantations established earlier and several private sector plantations, which are now beingestablished, will produce main share of commercial timber in Sri Lanka in the future. Many private forestcompanies claims to produce fast-grown timber in very short rotations such as 15- 25 years. Forestersnormally decide the age of felling based on the tree growth, (culminate point of MAI and CAI), but(Ruwanpathirana, 2002) suggested that maturation of different wood properties should also be consideredin deciding the rotation age.In this paper wood quality of fast grown plantation species are reviewed generally, with special referenceto three key commercial hardwood species, which will make major share of future timber supplies in SriLanka: Eucalyptus (Eucalyptus grandis, Mahogany (Swietenia macrophylla) and Teak (Tectonagrandis).

Avian conservation value of pine plantation forests in northern Vietnam

SummaryDecline of native forest cover is a worldwide concern. Recently, overall forest cover in Vietnam has increased, but most of the increase has been attributed to plantations of non-native trees. The conservation value of these plantations for birds is unknown. We compared avian species richness in pine plantations to that in second-growth and mature native forests in Tam Dao National Park, Vietnam. Bird species were classified into two categories: forest specialists or forest generalists. To account for strong heterogeneity in detection probabilities, the number of species in each category was estimated using the Pledger-Huggins estimator. We estimated total species richness and number of forest specialist species to be highest in mature forest (191; 95% CI = 96, 287, and 88; 95% CI = 47, 129 respectively), lower in second-growth forest (158; 95% CI = 87, 245 and 58; 95% CI = 18, 98 respectively), and lowest in pine plantation (106; 95% CI = 52, 158 and 49; 95% CI = 2, 97 respectively). The estimated number of forest generalist species was similar between mature forest and second-growth forest (103; 95% CI = 17, 189 and 100; 95% CI = 42, 158, respectively) and least in pine plantation (57; 95% CI = 31, 82). The maintenance of native forest types should receive priority for conservation in Vietnam and pine plantations should be managed to provide additional structure in the hope of increasing species richness.

Pérdida y fragmentación del bosque nativo en la cuenca del río Aysén (Patagonia-Chile) durante el siglo XX

This work estimates the loss and fragmentation of native forest in the watershed of the river Aysen during the 20 th century, as a result of clearance fires induced by land settlers. In order to generate the reconstruction of the native forest cover, several documentary records and GIS ArcView 3.2 were used. Different indexes of landscape changes were applied (area, density and size of the fragment, core area, euclidean distance, shape and aggregation index, and edge length) to estimate the distribution of the native forest between 1900 and 1998, which indicate that the main replacement of the forest was by prairies. A loss of approximately 23% of native forest was registered, also an increase in the number of forest fragments (<100 ha), as a result of the settlement process. Howerer, the increasing number of fragments has a high connectivity, wich was corroborated using different landscape indexes.

European Earth Observation Program: “Positive Synergy” Between Science and Society

Within the European Space Agency's (ESA) Earth Observation programs, a “positive synergy between science and society” comes across “very strongly,” according to Stephen Briggs, head of the program planning and coordination service for ESA's Directorate of Earth Observation Programmes. Briggs offered insights into the Earth Observation programs, including missions, data policy, and cooperation with other space agencies, during a 4 April town hall meeting at the European Geosciences Union's (EGU) annual meeting in Vienna, Austria. “One of the aspects that strikes everyone in Earth observation is the fact that when studying Earth science, it's not like looking at cosmology. We're looking at aspects of the Earth which inevitably have some consequence for society,” Briggs said, pointing to recent ESA satellite imagery of natural disasters, forest cover, ice sheets, and oceans.

Age of river basins in Guadeloupe impacting chemical weathering rates and land use

Abstract The Lesser Antilles have very high chemical weathering rates, with values that can reach 1290 t/km2/a. The tropical environment induces high precipitation rates, high temperature, dense vegetation, with sharp relief and thick soils. Because of volcanic activity, frequent pyroclastic flows produce very erodible and porous materials. In addition, agriculture induces important land use changes which replace existing native forest cover with banana and sugar cane plantations. Their surface can cover as much as 40% of the total area of a river basin. The aim of this study is to identify key parameters, either natural or anthropogenic, that control chemical weathering rates. Among the combined impact of all parameters (climate, runoff, slopes, vegetation etc.), basin age seems to be the control parameter: the younger the basin, the higher the weathering rate. A correlation between the chemical weathering rate and the basin age suggests that young volcanic rocks are more easily weathered than old ones: young fresh material is easily mobilized by erosion, while for older rocks with thick soil covers, chemical rates are much lower. A combined effect between the higher erodibility and a higher climate erosivity of the younger relief could be observed. Moreover, a correlation between banana plantations and the chemical weathering rates that can be explained by an increase of infiltration, due to stem flow processes is shown here. Banana plantations also have a correlation with the basin age, older basins being more favorable terrains for cultivation.