Skip to main content

page search

Issuesland managementLandLibrary Resource
Displaying 4141 - 4152 of 6741

Image interpreter tool: An ArcGIS tool for estimating vegetation cover from high-resolution imagery

Journal Articles & Books
December, 2011

Land managers need increased temporal and spatial resolution of rangeland assessment and monitoring data. However, with flat or declining land management and monitoring agency budgets, such increases in sampling intensity are unlikely unless new methods can be developed that capture data of key rangeland indicators at a lower cost. Remote sensing techniques have shown promise for collecting plant community composition and ground cover data efficiently. However, many image analysis techniques require software and expertise not always available to field offices.

Effects of management regimes and extreme climatic events on plant population viability in Eryngium alpinum

Journal Articles & Books
December, 2012

Extreme climatic events like the 2003 summer heatwave and inappropriate land management can threaten the existence of rare plants. We studied the response of Eryngium alpinum, a vulnerable species, to this extreme climatic event and different agricultural practices. A demographic study was conducted in seven field sites between 2001 and 2010. Stage-specific vital rates were used to parameterize matrix population models and perform stochastic projections to calculate population growth rates and estimate extinction probabilities.

Occurrence of native and exotic invasive trees in burned pine and eucalypt plantations: Implications for post-fire forest conversion

Journal Articles & Books
December, 2013
Portugal

Post-fire management objectives for monospecific forest plantations may include conversion to native broadleaved or mixed forests for purposes of diversification of forestry production, enhancing biodiversity and cultural value, or reducing biotic and abiotic hazards. Thus, the potential for post-fire conversion needs to be assessed as a first step in planning such conversion. On the other hand, fire occurrence may foster invasion by exotic species and this equally needs to be assessed when planning post-fire management.

Metal content in the waters of the upper Sanna River catchment (SE Poland): condition associated with drilling of a shale gas exploration wellbore

Journal Articles & Books
December, 2015

Detailed research on the content of heavy metals in ground and surface waters in the upper Sanna River catchment was initiated in 2013. The investigations were conducted in one of the most promising areas of potential shale gas extraction, in which the Frampol 1 test wellbore was drilled in 2012 (SE Poland, Roztocze Region). In the area of the wellbore, hydrochemical analyses of the waters of the river drainage zone were performed. Water was sampled from six objects representing soil water, porous groundwater, fissure-layer groundwater, and river water.

Current and Historical Variation in Wiregrass (Aristida stricta) Abundance and Distribution Is Not Detectable from Soil δ13C Measurements in Longleaf Pine (Pinus palustris) Savannas

Journal Articles & Books
December, 2013

Plant species distributions and transitions between vegetation types are determined by numerous factors, including disturbances such as fire. Documentation of past changes in the distribution and structure of fire-dependent ecosystems is necessary to assess the success of land management in maintaining historic vegetation types. In our study system—longleaf pine (Pinus palustris)-wiregrass (Aristida stricta) savannas and embedded wetlands (i.e., pocosins)—wiregrass is dependent on frequent burning.

Coronilla juncea is both a nutritive fodder shrub and useful in the rehabilitation of abandoned Mediterranean marginal farmland

Journal Articles & Books
December, 2002
Spain

Coronilla juncea is a leguminous shrub native to semi-arid regions of the Mediterranean Basin, particularly south-eastern Spain, and is browsed by livestock such as sheep and goats. We provide here information about this source of forage: allometric regression equations (phytovolume vs. total and forage phytomass), nutritive value and seed germination. The regression equations calculated were highly significant (r2= 0·86 for volume/total phytomass and 0·93 for volume/forage phytomass, p

stochastic movement simulator improves estimates of landscape connectivity

Journal Articles & Books
December, 2015

Conservation actions often focus on restoration or creation of natural areas designed to facilitate the movements of organisms among populations. To be efficient, these actions need to be based on reliable estimates or predictions of landscape connectivity. While circuit theory and least‐cost paths (LCPs) are increasingly being used to estimate connectivity, these methods also have proven limitations. We compared their performance in predicting genetic connectivity with that of an alternative approach based on a simple, individual‐based “stochastic movement simulator” (SMS).

Do Overlapping Land Rights Reduce Agricultural Investment? Evidence from Uganda

Journal Articles & Books
December, 2008
Uganda
Africa

While the need for land-related investment for sustainable land management and increased productivity is well recognized, quantitative evidence on agricultural productivity effects of secure property rights in Africa is scant. Within-household analysis of investments by owner-cum-occupants in Uganda points toward significant and quantitatively large investment effects of full ownership. Registration is estimated to have no investment effects, whereas measures to strengthen occupancy rights attenuate investment disincentives.

carbon balance of Norway: terrestrial and aquatic carbon fluxes

Journal Articles & Books
December, 2015
Norway

Northern landscapes accumulate carbon in vegetation and soils while rivers transport significant amounts of land-derived carbon to coastal areas. Here, we quantify carbon sources and sinks in main ecosystems (forests, peatlands, mountains, agricultural areas, lakes) in Norway for 1990–2008, and compare riverine carbon transport with terrestrial carbon accumulation in Norway’s four major discharge areas. Mean annual carbon accumulation (6.0 ± 0.9 Tg C; 19 g C m⁻²) in terrestrial ecosystems balanced 40 % of national greenhouse gas emissions.