Upland Afforestation Research Articles

The impact of upstream land use land cover change on downstream flooding: A case of Kuttanad and Meenachil River Basin, Kerala, India

The outcome of a conventional planning process is often a spatial plan which integrates the physical and fiscal development proposals prepared based on an administrative boundary that is entirely arbitrary. Due to its obvious demerits, this study therefore attempts to establish the significance of the ecological boundary-based planning approach which could address most of the environmental problems of consideration. Accordingly, the Kuttanad Wetland System in Kerala, India, is taken a case study for detailed analysis and exploration of the concept. The study demonstrates the correlation between the elevation profile of the area and the flood water pattern and signified how elevation profile impacts the accumulation of floodwaters. It was followed by the land use land cover (LULC) change analyses under five scenarios during 2005, 2011, 2015, 2025 (projected), and a regulated condition (idealistic case). The hydrologic modeling using SWAT and HEC-RAS substantiated that the increasing built-up and wasteland with the reduction in vegetation would accelerate the surface runoff rate.11Surface runoff is precipitation runoff over the landscape (USGS, 2020). Runoff rate means the volume rate of movement or quantity of stormwater flowing past a given point for time, expressed in cubic feet per second or gallons per minute (Runoff Rate, 2021).The projected LULC map of 2025 signified that the intensity of floods increased when the percentage built-up and wasteland increased. Similarly, the sprawl when curbed along with upland afforestation and floodplain restoration, lowered the intensity of floods. The study concludes by putting planning recommendations and policies showcasing the significance of ‘eco-urban and regional planning’, as a new concept and a framework that must be pursued at the earliest.

Is afforestation a driver of change in italian rivers within the Anthropocene era?

For eight rivers situated from northern to southern Italy, the evolutionary trajectories since the middle 19th century and the key controlling factors of channel adjustments were reconstructed using a combined diachronous-synchronous approach, integrating data from catchment- to reach-scale. The analysis takes advantage of multi-temporal GIS analysis of maps, aerial photographs, and orthophotos, and data from literature, archives, and official surveys of population and agrarian censuses. The main aims were to link historical channel responses to human and climate disturbances evidencing regional scale similarities and dissimilarities and to explain the role of upland and floodplain land use changes in the interpretation of channel adjustments.From the middle 19th century to the 1950s, both channel widening and narrowing were observed. These processes were related to land use disturbances (e.g., afforestation versus deforestation) acting at both reach and catchment scales. From the 1950s to 1970s, channel narrowing in some rivers accelerated simultaneously with forests encroachment on fluvial corridors and human abandonment of intense floodplain uses, before the action of any other factors. In southern Italian rivers, channel adjustments were more intense and occurred later than in northern ones, but they remained more active once adjustment ended. Even though these rivers underwent a rural decline, their floodplains were little colonized by mature forests, probably because of drier climatic conditions exacerbated by dewatering due to channel incision. This also means that upland afforestation, with its effects on bedload delivery, was a more critical driver in controlling narrowing than floodplain afforestation, as in this southern context we do not observe floodplain afforestation but grazing expansion. When forest can establish along the channel, as seen on the Volturno River, narrowing is even more important. River widening in the early 2000s–2010s did not compensate for longer term narrowing, demonstrating a shift in river responsiveness that was partly due to upland and floodplain afforestation inducing higher channel resistance to bank erosion and bedload deficit. Such morphological evolution was also observed in Southeastern France, but occurred a bit earlier, with stronger similarities with northern Italy and the Apennines. These drivers of change must not be underestimated in geomorphic diagnosis, even if they are more difficult to assess.

Riparian and Upland Afforestation: Improving Success by Excluding Deer from Small Areas with Low Fencing

We propose that small patches of land protected by low (1.2-m tall) fence is a viable approach for restoring and/or conserving forests in riparian or upland areas with high white-tailed deer (Odocoileus virginianus Zimmerman) populations. We also propose that this new approach may be advantageous because, unlike tree shelters, fenced areas protect shrubs just as well as trees in afforestation projects. Multi-year field experiments were performed involving deer exclosures where fence height and fenced area were manipulated in upland and lowland pasture and forest settings. Results show that low fencing significantly increased seedling survival and growth relative to unfenced areas when fenced areas were small (i.e., less than or equal to ∼100 m2). Moreover, tall fencing (1.8 or 2.3 m) did not provide significantly greater protection than shorter (1.2-m) fencing when the fenced areas were kept small. We propose that creating small patches of deer-free pasture or forest habitat will greatly support new approaches to afforestation such as applied nucleation. Finally, we show that low-stature fencing may also have application for protecting larger areas (≥0.8 ha) if the fencing is deployed around the perimeter as two low fences erected in parallel and with a small (3-m) space between them. We conclude that low fencing can result in levels of survival and growth of both trees and shrubs suitable to meet the success criteria for afforestation projects funded by the US federal government.

Simulating a century of soil erosion for agricultural catchment management

AbstractAgricultural land management requires strategies to reduce impacts on soil and water resources while maintaining food production. Models that capture the effects of agricultural and conservation practices on soil erosion and sediment delivery can help to address this challenge. Historic records of climatic variability and agricultural change over the last century also offer valuable information for establishing extended baselines against which to evaluate management scenarios. Here, we present an approach that combines centennial‐scale reconstructions of climate and agricultural land cover with modelling across four lake catchments in the UK where radiometric dating provides a record of lake sedimentation. We compare simulations using MMF‐TWI, a catchment‐scale model developed for humid agricultural landscapes that incorporates representation of seasonal variability in vegetation cover, soil water balance, runoff and sediment contributing areas. MMF‐TWI produced mean annual sediment exports within 9–20% of sediment core‐based records without calibration and using guide parameter values to represent vegetation cover. Simulations of land management scenarios compare upland afforestation and lowland field‐scale conservation measures to reconstructed historic baselines. Oak woodland versus conifer afforestation showed similar reductions in mean annual surface runoff (8–16%) compared to current moorland vegetation but a larger reduction in sediment exports (26–46 versus 4–30%). Riparian woodland buffers reduced upland sediment yields by 15–41%, depending on understorey cover levels, but had only minor effect on surface runoff. Planting of winter cover crops in the lowland arable catchment halved historic sediment exports. Permanent grass margins applied to sets of arable fields across 15% or more of the catchment led to further significant reduction in exports. Our findings show the potential for reducing sediment delivery at the catchment scale with land management interventions. We also demonstrate how MMF‐TWI can support hydrologically‐informed decision making to better target conservation measures in humid agricultural environments. Copyright © 2018 John Wiley & Sons, Ltd.

Migration, land use and forest change in St. Lucia, West Indies

Migration is a central feature of Caribbean societies, yet its consequences for land use and forest change have been little studied. This paper reviews the general history of human migration in the West Indies and its relationship to land use. It examines the case of post-war St. Lucia, in particular, focusing on the relationship between migration, land use change and forests in two watersheds. Out-migration to the UK and North America from 1950s–1970s contributed to reduced farming and increased upland afforestation. In the 1990s and early 2000s, a huge wave of farmland abandonment and ensuing afforestation swept across the island, triggered by WTO rulings that sharply eroded existing export markets for bananas, the country’s dominant crop. These effects were compounded by growing shortages of agricultural labor as men and women departed the countryside to work in the fast-growing, domestic construction, tourism and related service sectors. Since the late 1980s, a kind of ‘boomerang urbanization’ has occurred in which the return of earlier cohorts of out-migrants (who had departed rural areas to overseas urban centers in the 1950s, 60s and 70s) has fueled a residential home construction boom back home that is transforming extensive lowland agricultural lands and natural forests near the coast to peri-urban suburbs, while contributing to upland afforestation by drawing labor out of farming. This dramatic shift of environmental impacts away from the uplands to the lowlands and coasts appears widespread within the island Caribbean, but policy makers have been slow to acknowledge and respond to it.

45 years of non-stationary hydrology over a forest plantation growth cycle, Coalburn catchment, Northern England

Summary The Coalburn research catchment (1.5 km 2 ) in Kielder Forest, Northern England, is a long-term project to study the effect of upland afforestation on hydrology. There is now a unique 45-year record; making it Britain’s longest running forest hydrology research catchment. The site was instrumented in 1967, ploughed and planted in 1972/73 and the trees have now reached maturity. Hourly meteorological data have been measured since 1993 and these have enabled hydrological simulations to be carried out using the Shetran model for the period 1993–2011. The results from this work show that after ploughing there was an increase of around 50–100 mm in annual streamflow compared with the original upland grassland vegetation. However, the mature trees now show a decrease of around 250–300 mm in the annual streamflow compared with the original vegetation and a decrease of around 350 mm in the annual streamflow compared with when the site was ploughed. The simulation results show very clearly the non-stationary nature of the catchment during 1993–2011 with an annual increase in intercepted evaporation and a decrease in discharge as the trees grow. Simulation results also show that peak discharges are higher for a cover of smaller trees compared with taller trees. However, the results suggest that the bigger the event the smaller is the difference, i.e. there is absolute convergence for the two different tree scenarios at higher discharges. The study shows how modelling can compensate for data deficiencies, to maximise outcomes. As a rare example of long-term analysis of non-stationary catchment behaviour it also provides real evidence of change that would otherwise have had to be inferred theoretically.

CATCHMENT BEHAVIOR AND COUNTER-CYCLICAL WATER TRADE: AN INTEGRATED MODEL

ABSTRACT. Murray Basin water resources are under increasing pressure to satisfy often conflicting environmental and economic objectives. Governments, as the “environmental steward,” have several management options including water trading and banking water until it can be used to greatest effect and occasionally selling water back to irrigators. This is sometimes known as counter-cyclic trading. To examine the potential of the above options, a model of water trading and banking in a simple market is developed. The model combines a catchment hydrology model with economic information that drives land use practice and demand for water. Simulations are used to explore these options at a strategic level. The potential impacts of increased upland afforestation and climate change on catchment hydrology in the presence of a pro-active environmental steward are considered. It is concluded that in a system where entitlements are capped it is likely that the most cost-effective management system will involve counter-cyclic trading.

An assessment of the impact of upland afforestation on lowland river reaches: the Afon Trannon, mid-Wales

Upland afforestation in the UK was the largest rural land-use change last century. As a consequence, the bed load yields of upland catchments increased substantially. Circumstantial evidence suggests that, when this increased load reaches the lowland catchment, it is deposited, triggering flow diversion and channel instability. However, despite the widespread adoption of this theory, it remains to be properly tested. This paper uses aerial photograph analysis and contemporary channel digital terrain models (DTMs) to assess this concept on the Afon Trannon, mid-Wales, the upper catchment of which was afforested between 1948 and 1978. Construction of a sediment budget demonstrates that upland catchment bed load yields are only equivalent to localized inputs of gravel from bank erosion and are therefore unlikely to be totally responsible for producing the high rates of channel change observed in some lowland reaches. Channel instability appears to be more related to the nature of the local bank input as those reaches where gravel is not present in the bank material are stable. Additionally, flood magnitude and frequency are shown to have increased since 1988, a factor of at least equal importance to that of bed load yields from either upland catchments or local bank erosion. It is concluded that, in contrast to previous work, afforestation in the uplands has only a minor influence on downstream reaches of the Afon Trannon. Situations where upland afforestation may have a greater impact on downstream reaches are discussed and the implications for best management practice explored.

Scale effects on the hydrological impact of upland afforestation and drainage using indices of flow variability: the River Irthing, England

Abstract. Frequent assertions by river users that rivers in northern England now rise and fall more quickly than in the past, have never been validated by analysis on catchments of more than 10 km2. The method using indices of flow variability provides a basis for making direct measurements of the annual number and duration of pulses, i.e. rises above a given flow, and for comparing catchments of different sizes. A comparison is made between the small afforested headwater Coalburn catchment (1.5 km2) and the larger River Irthing catchment (335 km2) on which the afforested area comprises 19%. A simple but effective means is provided for decoupling the effect of climatic variability from the effects of land use. The analysis shows that major changes have occurred on the small catchment, first with rising pulse numbers after pre-afforestation drainage, then with a much greater progressive decrease in pulse number accompanied with increasing pulse duration. In contrast, the larger catchment shows little change in variability indices from the beginning of its record in 1968 until the late 1980s after which the pattern of change mirrors that at Coalburn but the proportional change is much smaller. The direction of change is the opposite of that asserted by river users. Keywords: hydrology, flow variability, land-use impacts, forests, scale effects

The use of indices of flow variability in assessing the hydrological and instream habitat impacts of upland afforestation and drainage

Although the impact of plantation forestry and ground-preparation drainage on headwater runoff response has been widely studied, there are remaining uncertainties concerning the time scale of changes, scale effects of catchment size and impacts on flow variability. Flow variability, along with changes in sediment loads and water quality, is likely to be a defining element of the overall instream habitat quality of headwater catchments. In this paper a method is described for the characterisation of flow variability using 15-min data on the 1.5 km 2 Coalburn catchment, from 1967 to 1998, over a period of change from natural moorland to closed canopy coniferous forest. The method is based on annual number, and average and total duration of pulses above selected threshold flows but decouples the effects of variable annual rainfall. The number of pulses increased from pre- to post-drainage but pulse number has declined steadily and pulse duration increased with forest growth—the catchment has become more, then less ‘flashy’. The method provides a comprehensive, continuous and quantitative picture of changes in hydrological regime that is relevant to current assessments of instream physical habitat and ‘environmentally acceptable flows’. It is possible that low invertebrate numbers and low levels of fish recruitment in the Coalburn channel may be in part attributable to changes in flow regime.

Changing headwater suspended sediment yields in the LOIS catchments over the last century: a paleolimnological approach

This paper describes the methods used to reconstruct suspended sediment yields over the last century, based on 210Pb and 137Cs dated bottom sediments in nine lake and/or reservoir catchments. Magnetic susceptibility and dry bulk density are used to correlate between multiple cores taken from each lake/reservoir basin in order to estimate sediment influx through time and reconstruct sediment yield histories. The catchments represent a range of morphological and land use systems, including upland moorland, upland forestry and upland and lowland agricultural systems. The reconstruction provides some background information on pre-20th century sediment yields and permits an evaluation of the effect of 20th century land management systems, especially upland afforestation and agriculture, on changing suspended sediment yields. Reconstructed sediment yields over the last century range from c. 7 to 86 t km−2 yr−1. Average post-1953 yields from pasture, arable, moorland and forested catchments are 13, 31, 29 and 13 t km−2 yr−1, respectively. The history of human disturbance in individual catchments is clearly recorded in the reconstructed sediment yields. Short-lived disturbance, such as afforestation, produces high yields (over 40 t km−2 yr−1) for up to a decade after planting, but yields subsequently decline to pre-planting levels (c. 12 t km−2 yr−1). Sustained increases in sediment yield are associated with arable, mixed agricultural and, to a lesser extent, grazing systems. While the strong controls exerted on sediment yield by human disturbance mask the potential effect of regional contrasts in runoff and topography between catchments, there is some evidence to suggest that a long-term climate change signal is recorded in the temporal trends in sediment yield from an analysis of Lamb weather types. Copyright © 1999 John Wiley & Sons, Ltd.

Effects of Upland Afforestation on Some Birds of the Adjacent Moorlands

(1) This study examined the possibility that upland forestry plantations may affect the numbers of birds on adjacent unplanted moorlands. (2) Bird numbers were estimated on areas adjacent to conifer plantations at sixty-two sites, each of 640 ha, in three areas of northern Scotland. 1 (3) The results varied between study areas, but some bird species and some vegetation types differed in abundance with distance from the forest edge in some study areas. (4) When the effects of vegetation differences were statistically removed, there were no major effects of forest proximity on the numbers of curlew, red grouse, dunlin and golden plover. (5) Differences in vegetation at different distances from plantations, and adjacent to plantations of different ages, might be caused by the growth of trees or changes in management next to afforested land. However, map-derived habitat measures, which cannot have been affected by either tree-planting or management, also differed with plantation age and proximity. (6) The results suggest that there are no edge effects, either positive or negative, of conservation importance for birds around forestry plantations in northern Scotland.

Current rural land-use issues in Scotland: an overview

ABSTRACT Land use in Scotland's countryside is currently an issue of major public concern, largely because of a sea-change in agricultural policy which seemslikely to lead to the withdrawal of some land from agricultural use. In addition, there has been concern about the scale of upland afforestation, about land availability for housebuilding, and about claims on land for conservation and for rural development. This article provides an overview of these current landuse issues in Scotland.

Buzzard breeding distribution and abundance in Britain and Northern Ireland in 1983

The British breeding range of Buzzards contracted in the nineteenth century, due mainly to persecution by gamekeepers. A partial recovery occurred after the First World War, but the species remained more or less restricted to western Britain. A survey was conducted in 1983 to see whether the Buzzard had re-colonized any more of its former range since the 1968–72 Breeding Atlas. The survey showed that there had been some improvement, especially in Northern Ireland, but that east and northeast Scotland was an obvious exception to this trend, due (apparently) to continued persecution there. Elsewhere, recolonization has occurred mainly along the edges of the Buzzard's range, but largely through infilling, with little sign of eastwards expansion since 1968–72. Within the Buzzard's main range along the western side of Britain, mean densities of soaring birds were higher in England and Wales than in Scotland. The population may now be in the order of 12 000–15 000 territorial pairs. Factors which currently influence the range and abundance of Buzzards are discussed; these include upland afforestation and human persecution.

On the acceptability of afforestation schemes

Upland afforestation has caused major conflicts with conservation interests in the UK, nowhere more so than in the national parks of England and Wales. This article reviews the responses made by the national park authorities to the 250 afforestation proposals made in the ten parks between 1974 and 1984. It apparently mattered little who made the proposal nor in which park the proposal was located. Responses were, however, greatly affected by proposal size, with park authorities more likely to react adversely to larger proposals. This finding is discussed in relation to the future of forestry in upland and lowland Britain.

Upland afforestation: influences on stream hydrology and chemistry

. Afforestation in the British uplands can lead to changes in the hydrology, sediment load and chemistry of streams. These changes may affect water resource management costs, stream biota and the health of fisheries. Some of the changes can be related to specific phases of the forest management cycle, e.g. site preparation, fertilization, felling; modifications in management practice can limit their impact. Other changes in water yield and chemistry seem to have complex origins in forest-atmosphere and forest-soil interactions; these are more difficult to counteract.

Agricultural and afforestation controls: Conservation and ideology

Agriculture and upland afforestation have caused major changes to the landscapes of the UK as well as severe damage to nature conservation interests since the second world war. The major task now is to secure greater influence over the activities of farmers and foresters. This article reviews the calls that have been made over the last 25 years by national environmental bodies for the extension of planning controls to agricultural operations and to afforestation. The advocacy of controls is now a party political issue and the implications of this are considered.

FORESTRY'S GREAT ESCAPE

Summary Few will be surprised at the Government's rejection of the Countryside Commission's recent recommendation that the larger upland afforestation schemes be subject to planning control. And yet the calls for afforestation controls which grew within the rural amenity lobby through the sixties and seventies attracted Conservative support and Labour opposition. That pattern changed in the early eighties when Labour adopted, in advance of any national environmental organisation, a policy of agricultural controls. The politically more important agricultural issue now dominates and today Labour advocates planning control of agriculture and afforestation, whilst the Tories reject controls of agriculture and afforestation. Arguably, the foresters' (and the farmers') best strategy now is to use what time remains under Tory administrations to so develop an effective co-operative system that the calls for control disappear.

The Effects on Song-Bird Populations of Upland Afforestation with Spruce

The Effects on Song-Bird Populations of Upland Afforestation with Spruce

Thomas Johnes (1748–1816)— Pioneer of Upland Afforestation in Wales

Thomas Johnes (1748–1816)— Pioneer of Upland Afforestation in Wales