Housing growth,forests, and public lands in Northern Wisconsin from 1940 to 2000

Rural, forested areas throughout the United States are experiencing strong housing growth with potentially detrimental impacts on the environment. In this paper, we quantify housing growth in Northern Wisconsin over the last sixty years to determine if growth rates were higher near public lands, which may represent an important recreational amenity. We used data from the U.S. Census to produce decadal housing density estimates, “backcasts,” from 1940 to 2000 for northern Wisconsin to examine “rural sprawl” in northern Wisconsin and its relationship to forested areas and public lands. We integrated housing density estimates with the 1992/1993 National Land Cover Dataset to examine the relationship between rural sprawl and land cover, especially forests. Between 1940 and 2000, private land with <2 housing units/km² decreased from 47% to 21% of the total landscape. Most importantly, housing growth was concentrated along the boundaries of public lands. In 14 of the 19 counties that we studied, housing growth rates within 1 km of a public land boundary exceeded growth rates in the remainder of the county, and three of the five counties that did not exhibit this pattern, were the ones with the least amount of public land. Future growth can be expected in areas with abundant natural amenities, highlighting the critical need for additional research and effective natural resource management and regional planning to address these challenges.     

Grassland Plant Composition Alters Vehicular Disturbance Effects in Kansas,USA

Many “natural” areas are exposed to military or recreational off-road vehicles. The interactive effects of different types of vehicular disturbance on vegetation have rarely been examined, and it has been proposed that some vegetation types are less susceptible to vehicular disturbance than others. At Fort Riley, Kansas, we experimentally tested how different plant community types changed after disturbance from an M1A1 Abrams tank driven at different speeds and turning angles during different seasons. The greatest vegetation change was observed because of driving in the spring in wet soils and the interaction of turning while driving fast (vegetation change was measured with Bray-Curtis dissimilarity). We found that less vegetation change occurred in communities with high amounts of native prairie vegetation than in communities with high amounts of introduced C₃ grasses, which is the first experimental evidence we are aware of that suggests plant communities dominated by introduced C₃ grasses changed more because of vehicular disturbance than communities dominated by native prairie grasses. We also found that vegetation changed linearly with vehicular disturbance intensity, suggesting that at least initially there was no catastrophic shift in vegetation beyond a certain disturbance intensity threshold. Overall, the intensity of vehicular disturbance appeared to play the greatest role in vegetation change, but the plant community type also played a strong role and this should be considered in land use planning. The reasons for greater vegetation change in introduced C₃ grass dominated areas deserve further study.     

矿山废弃地的生态恢复

本文通过对矿山废弃地及其恢复情况调查,分析了我国矿山废弃地生态恢复的方向及蕴藏的产业机遇。     

Wildfire Policy and Public Lands: Integrating Scientific Understanding with Social Concerns across Landscapes

Abstract:  Efforts to suppress wildfires have become increasingly problematic in recent years as costs have risen, threats to firefighter safety have escalated, and detrimental impacts to ecosystems have multiplied. Wildfires that escape initial suppression often expand into large, high-intensity summer blazes. Lost is the legacy of smaller fires that likely burned outside extreme weather and fuel conditions and resulted in less severe impacts. Despite the recognized need for modifications to existing policies and practices, resource agencies have been slow to respond. The spread of exotic species, climate change, and increasing human development in wildlands further complicates the issue. New policies are needed that integrate social and ecological needs across administrative boundaries and broad landscapes. These policies should promote a continuum of treatments with active management and reduction of fuel hazard in wildland-urban interface zones and reintroduction of fire in wildlands. Management goals should focus on restoration of the long-term ecological health of the land. Projects that reduce fuel loads but compromise the integrity of soil, water supplies, or watersheds will do more harm than good in the long run. Despite significant ecological concerns, learning to live with fire remains primarily a social issue that will require greater political leadership, agency innovation, public involvement, and community responsibility.     

Dependable Water Supplies from Valley Alluvium in Arid Regions

Reliable sources of high-quality water for domestic use are much needed in arid regions. Valley alluvium, coarse sand and gravel deposited by streams and rivers, provides an ideal storage medium for water in many regions of the world. However, river sediments will not accumulate in a valley without a natural or artificial barrier to slow the water. Sediments will deposit upstream of a barrier dam and form an alluvial deposit of relatively well-sorted material. The alluvium then acts as both an underground water-supply reservoir and a water filter, yielding a constant flow of high-quality water. Trap dams that store water in alluvial sediments and slowly release the filtered water represent an appropriate and inexpensive technology for combating desertification and mitigating the effects of drought at the community level. Small trap dams may be built as a community project using local materials and local labor.     

Complementary benefits of tourism and hunting to communal conservancies in Namibia

Tourism and hunting both generate substantial revenues for communities and private operators in Africa, but few studies have quantitatively examined the trade‐offs and synergies that may result from these two activities. We evaluated financial and in‐kind benefit streams from tourism and hunting on 77 communal conservancies in Namibia from 1998 to 2013, where community‐based wildlife conservation has been promoted as a land‐use that complements traditional subsistence agriculture. We used data collected annually for all communal conservancies to characterize whether benefits were derived from hunting or tourism. We classified these benefits into 3 broad classes and examined how benefits flowed to stakeholders within communities under the status quo and under a simulated ban on hunting. Across all conservancies, total benefits from hunting and tourism increased at roughly the same rate, although conservancies typically started generating benefits from hunting within 3 years of formation as opposed to after 6 years for tourism. Disaggregation of data revealed that the main benefits from hunting were income for conservancy management and food in the form of meat for the community at large. The majority of tourism benefits were salaried jobs at lodges. A simulated ban on trophy hunting significantly reduced the number of conservancies that could cover their operating costs, whereas eliminating income from tourism did not have as severe an effect. Given that the benefits generated from hunting and tourism typically begin at different times in a conservancy's life‐span (earlier vs. later, respectively) and flow to different segments of local communities, these 2 activities together may provide the greatest incentives for conservation on communal lands in Namibia. A singular focus on either hunting or tourism would reduce the value of wildlife as a competitive land‐use option and have grave repercussions for the viability of community‐based conservation efforts in Namibia, and possibly other parts of Africa.     

Post-frontier governance up in smoke? Free-for-all frontier imaginations encourage illegal deforestation and appropriation of public lands in the Brazilian Amazon

ABSTRACT

Post-frontier governance in the Brazilian Amazon highlights the interaction of regulatory technologies, institutions and practices to combat illegal deforestation and appropriation of public lands. While the Amazon fires received tremendous media coverage in 2019, the dismantlement of environmental laws and regulatory agencies has supported the rise in deforestation as early as 2012. We discuss the impact of post-frontier governance in Southwest-Pará by analyzing the spatial distribution of deforestation, territorial management, law enforcement, and environmental regularization from 2000 to 2018. The integration of spatial analysis with qualitative field surveys in the blacklisted municipality Novo Progresso shows that deforestation control largely fails, specifically in undesignated public lands. While land tenure security remains the biggest challenge in the region, the persistent imagination of free-for-all frontier spaces encourages the uncontrolled appropriation of and speculation with public lands. Here, the Rural Environmental Registry (CAR) has been identified as a key instrument to secure land claims.     

Devising Appropriate Policies and Instruments in Support of Private Conservation Areas: Lessons Learned from the Klein Karoo,South Africa

Abstract: The amount of privately conserved land is increasing worldwide. The potential of these areas to contribute to the global conservation of biodiversity is significant, given that statutory protected areas alone will not suffice. Nevertheless, there is still inadequate support for private conservation areas, and further research on appropriate, flexible, and generally applicable incentive measures is necessary. We conducted 25 semistructured interviews with the owners of private conservation areas in the Little Karoo, South Africa, to examine landowner opinions of existing conservation policies and their relationships with the local conservation authority. We also assessed landowner preferences regarding conservation incentive measures. Landowners doubted the conservation authority's capacity to implement its stewardship program and were also discouraged by the bureaucracy of the program. The conservation authority was often viewed negatively, except where landowners had experienced personal contact from conservation staff or where strong social capital had formed among landowners. Landowners did not desire financial rewards for their conservation efforts, but sought recognition of their stewardship role and greater involvement from the conservation authority through personal contact. We conclude that conservation policies for private lands could benefit from the provision of extension services to landowners, promotion of formation of groups of landowners and other stakeholders, and public acknowledgment of the contributions private conservation areas make.     

Effects of Private‐Land Use,Livestock Management,and Human Tolerance on Diversity,Distribution, and Abundance of Large African Mammals

Successful conservation of large terrestrial mammals (wildlife) on private lands requires that landowners be empowered to manage wildlife so that benefits outweigh the costs. Laikipia County, Kenya, is predominantly unfenced, and the land uses in the area allow wide‐ranging wildlife to move freely between different management systems on private land. We used camera traps to sample large mammals associated with 4 different management systems (rhinoceros sanctuaries, no livestock; conservancies, intermediate stocking level; fenced ranches, high stocking level; and group ranches, high stocking level, no fencing, pastoralist clan ownership) to examine whether management and stocking levels affect wildlife. We deployed cameras at 522 locations across 8 properties from January 2008 through October 2010 and used the photographs taken during this period to estimate richness, occupancy, and relative abundance of species. Species richness was highest in conservancies and sanctuaries and lowest on fenced and group ranches. Occupancy estimates were, on average, 2 and 5 times higher in sanctuaries and conservancies as on fenced and group ranches, respectively. Nineteen species on fenced ranches and 25 species on group ranches were considered uncommon (occupancy < 0.1). The relative abundance of most species was highest or second highest in sanctuaries and conservancies. Lack of rights to manage and utilize wildlife and uncertain land tenure dampen many owners’ incentives to tolerate wildlife. We suggest national conservation strategies consider landscape‐level approaches to land‐use planning that aim to increase conserved areas by providing landowners with incentives to tolerate wildlife. Possible incentives include improving access to ecotourism benefits, forging agreements to maintain wildlife habitat and corridors, resolving land‐ownership conflicts, restoring degraded rangelands, expanding opportunities for grazing leases, and allowing direct benefits to landowners through wildlife harvesting. Efectos del Uso Privado de Suelo, Manejo de Ganado y la Tolerancia Humana sobre la Diversidad, Distribución y Abundancia de Mamíferos Mayores Africanos     

利用多信息源提高半干旱地区TM影像的森林类型制图精度:以北京西部山区为例

以地处半干旱地区的北京西部山区为例,利用研究区森林类型的季相特征、已有的少部分林相图、Google Earth免费影像数据等信息选择不同坡向的相同森林类型做训练样本,通过加入其他辅助数据(海拔和坡向数据),来提高Landsat TM影像的森林类型分类精度,同时对比了基于像元和面向对象方法提取森林类型的效果。结果表明:1)就半干旱山区的森林类型划分来说,TM影像的TM4、TM5、TM4-TM2及辅助数据DEM和坡向可作为TM影像森林类型划分的最佳数据源。2)单独加入海拔信息,阔叶林的提取精度提高23%,针叶林和混交林的分类精度只提高了4%~5%;单独加入坡向信息,阔叶林的提取精度只提高21%,但是针叶林和混交林的分类精度则分别提高了13%、18%,显著优于单独加入海拔信息的效果。同时加入海拔信息和坡向信息,至少可以准确区分出约70%以上的针叶林、阔叶林和混交林。3)就本研究区而言,坡向比海拔更有效地辅助提高森林分类精度。4)就混淆矩阵数据而言,面向对象的分类方法比基于像元分类结果总体精度低3%,Kappa系数低4%,但面向对象的分类结果更加符合研究区实际情况。该研究对中分辨率影像应用于半干旱山区森林类型划分具有一定的借鉴意义。