Kimberly E. Medley

Ecosystem processes along an urban-to-rural gradient

In order to understand the effect of urban development on the functioning of forest ecosystems during the past decade we have been studying red oak stands located on similar soil along an urban-rural gradient running from New York City ro rural Litchfield County, Connecticut. This paper summarizes the results of this work. Field measurements, controlled laboratory experiments, and reciprocal transplants documented soil pollution, soil hydrophobicity, litter decomposition rates, total soil carbon, potential nitrogen mineralization, nitrification, fungal biomass, and earthworm populations in forests along the 140 × 20 km study transect. The results revealed a complex urban-rural environmental gradient. The urban forests exhibit unique ecosystem structure and function in relation to the suburban and rural forest stands; these are likely linked to stresses of the urban environment such as air pollution, which has also resulted in elevated levels of heavy metals in the soil, the positive effects of the heat island phenomenon, and the presence of earthworms. The data suggest a working model to guide mechanistic work on the ecology of forests along urban-to-rural gradients, and for comparison of different metropolitan areas.

Landscape change with agricultural intensification in a rural watershed, southwestern Ohio, U.S.A.

Specialized cash grain production, emergent in the midwestern United States during the post-WWII era, typifies the Upper Four Mile Creek watershed in southwestern Ohio. This style of agriculture intensifies cropland use, with consequent increases in soil erosion and stream sedimentation - a serious problem in the lower reservoir, Acton Lake. Agricultural statistics and aerial photographs compiled between 1934 and 1984 were used to quantify agricultural dynamics and landscape change in the watershed, including land-use apportionment, diversity, and the structural configuration of forest, woodland, and old-field/brushland patches and corridors. A questionnaire sent to all land owners in the basin documented farm-level characteristics and factors that influence management decisions. Crop diversity (H′) in Preble County, Ohio decreased from 1.42 in 1934 to 1.17 in 1982, as corn and soybeans dominated the landscape mosaic. Yields rose, but net profits were reduced by declining prices per bushel and increases in fertilizer and petroleum-based subsidies. Landuse diversity in the county also declined (H′ = 1.37 in 1934 tot 0.80 in 1982) in response to cropland expansion, whereas forest land in the watershed increased from 1605 to 2603 ha. Fragmentation declined and the landscape became polarized after 1956, with a concentration of agricultural patches in the upper watershed and forest-patch coalescence in stream gullies and state park land in the lower watershed. The questionnaire (~ 29% return) further supported, at the farm-level, observed regional trends toward expansion (farm coalescence and lease contracts) and specialization (conversion toward corn and soybeans). The most important factors influencing farm size and management were better equipment and family traditions. Thus, cultural and technological factors that operate at the farm-level, coupled with meso-scale variation in the physical conditions of a catchment basin, tend to influence landscape-level patterns more than regional socioeconomics and governmental policies.

Landscape analysis of jaguar ( Panthera onca ) habitat using sighting records in the Sierra de Tamaulipas, Mexico

The Sierra de Tamaulipas is a biogeographically isolated mountain system in Northern Mexico, where habitat fragmentation by land-management practices is a possible threat to wildlife conservation. As a case example, we used GIS analyses to evaluate how human activities influence the landscape structure of jaguar (Panthera onca) habitat in the region. The study: (I) ranked potential habitat based on associations between environmental attributes (topography, streams and vegetation) and the frequency distribution of jaguar sighting records; (2) classified current land cover from a 1990 Landsat-TM image and mapped the landscape structure of high potential habitat; and (3) compared the degree to which mature natural vegetation is fragmented by different types of owners. Jaguar sites showed significant associations with tropical deciduous and oak forests, and low, west or south-east slopes, between 400 and 900 m. About 52% of the high potential habitat was mapped as mature natural vegetation, which was distributed as two large patches (28% of the land area) and many small forest patches (98% at < 80 ha). The number and size-class distribution of high-potential habitat patches varied little amongst four ownership types, but the dispersed distribution of more subsistence and commercial-based owners across the landscape suggests the need for collaborative participation in a conservation plan. From our study the need to scale up from managing individual land parcels is substantiated and areas that promote regional contiguity of jaguar habitat in the Sierra de Tamaulipas are identified.

DISTRIBUTION OF THE NON-NATIVE SHRUB LONICERA MAACKII IN KRAMER WOODS, OHIO

This study examined the distribution of Lonicera maackii (Amur honey-suckle) in a 5.2-ha old-regrowth deciduous forest in southwestern Ohio, and focused on its associations with: (1) forest-edge and internal-forest conditions; and (2) composition and structure of the native flora. Fine-scale vegetation patterns were measured in 60 nested plots and mapped with a geographic information system. L. maackii accounted for 24% of the relative importance of understory trees and shrubs based on its density (3361/ha), frequency (95%), and basal area (1.89m2/ha). Within-patch densities correlated significantly with edge attributes, but stem-basal areas were best explained by a covariate model that coupled edge conditions with internal topographic settings. Detrended correspondence analysis identified spatial patterns of community diversity in the understory native flora, and honeysuckle abundances were highest in small discontinuous community patches. Species richness and densities of native shrubs (Lindera benzoin ...

Extractive forest resources of the Tana River national primate reserve, Kenya

Plant uses by the Pokomo and their influence on riverine forest structure and composition are examined in the Tana River National Primate Reserve, Kenya. Of a total 98 plant species identified with one or more uses, 15 are used as food, 34 for construction material, 43 for technology, 23 for remedy, 2 for commerce, and 20 for other uses. The mean basal area of cut wood is 3.21 m2/ha, mostly from palms (1.96 m2/ha) and understory trees (1.20 m2/ha). Measured impacts on forest structure include the loss of large trees for canoes or beehives, lowered palm heights, and tree coppicing. Accessibility explains much of the spatial pattern of use. Extraction activities do not reduce forest area, and causal effects on productivity are complicated by the heterogeneous environment and past disturbances. In view of regional pressures on forests and cultural traditions, limited resource extraction offers incentives for local stewardship of a unique ecosystem.RésuméSe examinan el uso de las plantas por los Pokono, y la influencia de estos en la estructura y composición de bosque de galería de la Reserva Nacional para Primates Ró Tana, Kenya. Del total de 98 especies identificadas con uno o más usos, 15 son usadas como aliemento, 34 para materiales de construcción, 23 para remedio, 2 para comercio y 20 tienen otros usos. El área basal promedio de la modern en rodal es 3.21 m2/ha, la mayoría proviene depalmas (1.96 m2/ha) ye de árboles del sotobosque (1.20 m2/ha). Los impactos medidos en la estructura del bosque incluyen, a péridida de árboles de gran altura para construcción de canoas o de colmenares, la baja en estatura de las palmas y los rebrotes múltiples de los arboles cortados. La accesibilidad explica en mucho, el patrón espacial de uso. La actividad extractiva no reduce el area de bosque, no obstante, los efectos de causa en la productividad se vuelven complejos debido a la heterogeneidad ambiental y a disturbios previos. En vista de las presiones regionales ejercidas sobre los bosques y las tradiciones culturales, la extracción limitada de recursos ofrece incentivos para la administración local de un ecosistema sin igual (el bosque de galería).

Historical Changes in Forest Cover and Land Ownership in a Midwestern U.S. Landscape

Abstract Environmental history in the Midwestern Corn Belt includes changes through time in landowners and their consequent effect on agricultural and uncultivated land resources. We examined these changes in Israel Township, southwestern Ohio, using archival accounts from the mid 1800s, land-cover maps compiled from 1935, 1956, and 1984 aerial images, and land-ownership records from 1912, 1940, 1968, 1974, 1983, and 1989 parcel maps. Historical records document the clearing of beech-maple forests for agriculture and show the economic contributions of forests to early settlement. Between 1935 and 1984, agricultural lands declined from 84 percent to 78 percent and forests increased from 10 percent to 19 percent. These are slight changes in comparison with the more than 90 percent of the uncultivated lands that experienced transitions among land uses. We document a decline in land-cover diversity, with losses in successional lands and most forest growth localized to lower stream valleys and Hueston Woods State Park. The amount of land in farms (≥3-ha tracts) declined slightly, from 99 percent to 88 percent, but 79 percent of the land showed two to three changes in landowners and 16 percent showed four to five changes over the study period. Parcels with low turnover had the greatest percent of their land in forest, larger mean forest-patch sizes, and the greatest percent gains in forest area. Our results support coordinated efforts focused on factors that influence stable farm ownership and promote a diversity of environmental and economic gains from forests in the rural landscape.

An Ecological Framework for Participatory Ethnobotanical Research at Mt. Kasigau, Kenya

Vegetation changes from Commiphora-Acacia bushland, through farms and homesteads, and to woodland and evergreen forest defined an ecological gradient for investigating woody plant resources on a mountain in the Eastern Arc, southeast Kenya. The authors describe plot sampling on the composition and structure of woody plants, a corresponding floristic inventory, and qualitative methods used to compile ethnobotanical data and validate local knowledge on plant use. Participant observations, mapping exercises, and free listing increased the opportunities for discussion about plant resources. The authors also describe ways to share results with villagers and a collaborative plant guide.

Ethnobotanical Survey of 'Wild' Woody Plant Resources at Mount Kasigau, Kenya

ABSTRACT This paper focuses on the naming and use of plants by Taita who live at Mount Kasigau in Kenyas Eastern Arc Mountains. Plant vouchers and ethnobotanical data were compiled from transects and within 55 ecological plots, and during participant observations, home surveys, and semi-structured interviews with residents. Between 2002 and 2006, we recorded 338 wild woody plants in 74 families and 208 genera. Kasigau Taita named 252 of these plants and described 758 material uses or ecosystem services for 205 plants. Most plants with uses occurred in montane woodland (650–1000 m), the bushland (<650 m) comprised most of the plant uses, and <7% of the plants in evergreen forest (>1000 m) had a described use. Local residents also enriched the availability of resources around their homes and farms. Extra-local pressures for commerce posed the greatest threat to biodiversity conservation and the sustainable provision of woody plant resources for local livelihoods.

Invasion Dynamics of Nonnative Amur Honeysuckle Over 18 Years in a Southwestern Ohio Forest

Abstract A study over time provides a unique approach to investigate if landscape-environmental conditions can explain community resistance to invasion by nonnative plants in protected forest patches. This study investigated overall and intra-forest spatial patterns of change in nonnative Lonicera maackii (Amur honeysuckle) after 18 y in a 5.2 ha mature deciduous forest in southwestern Ohio. Changes in height-class abundances were measured in 60 permanent plots and mapped using GIS. Amur honeysuckle density increased from 3361 to 5472 individuals/ha (62.8%), but increases and decreases occurred at different sample plots. Greatest increases were for individuals <1 m (86.3%). A repeated measures MANOVA confirmed the significant effects of time (1992–2010) for total density, density of individuals >1 and <1 m, and mean height, but the decrease in mean height (1.44 to 1.30 m) was not significant in the univariate analysis. Morans I statistic calculations documented nonsignificant spatial autocorrelations among plots, but landscape-environmental attributes have weak and mostly non-significant relationships with the change in honeysuckle densities among the plots. Management practices can decrease propagule pressure along edges and reduce the establishment of small individuals in the interior, but Amur honeysuckle is likely to remain as a naturalized understory shrub that responds to spatially fluctuating resources in this mature forest fragment.

Landscape Mapping: Gaining “Sense of Place” for Conservation in the Manaslu Conservation Area, Nepal

Abstract Satellite mapping contributes significantly to ecological studies of landscape composition and structure but needs to better engage local populations in more culturally sensitive assessments of diversity patterns. This study examines how participatory mapping can contribute to land-cover analyses derived from satellite data of landscapes in the Manaslu Conservation Area (MCA), Nepal. Landscapes were mapped by local residents, first on paper and again on a geo-registered Landsat Thematic Mapper (TM) scene, for April 7, 2010. Local landscape knowledge from men and women was transferred from participatory maps to the classified satellite image to create an integrated landscape map for the MCA. Participatory maps added the significance of “place” to the evaluation of landscape diversity (n = 276 named places for women and 315 for men). The classification of the TM image resulted in seven land cover types with only 10% of the land classified as forests, which are highly fragmented. The final map combined local landscape knowledge (n = 43 places mapped on the TM image and n = 21 from the transect walks) with the empirical classification of land cover types, increasing the spatial understanding of MCA as a “place” of material use and cultural meaning. This integrative map, as process and outcome, promoted collaborative learning about local places and local peoples’ perspectives on their landscape, which can contribute to more adaptive landscape planning and conservation of forest and livelihood resources.