-
Dettmers, Randy
-
I work on conservation planning (biological foundation and landscape design) for birds of conservation concern, with a focus on landbirds, as well as designing and implementing monitoring programs to track population status of such species and evaluate the success of conservation actions for these species.
Located in
Expertise Search
-
Domesticated Nature: Shaping Landscapes and Ecosystems for Human Welfare
-
Like all species, humans have exercised their impulse to perpetuate and propagate themselves. In doing so, we have domesticated landscapes and ecosystems in ways that enhance our food supplies, reduce exposure to predators and natural dangers, and promote commerce. On average, the net benefits to humankind of domesticated nature have been positive. We have, of course, made mistakes, causing unforeseen changes in ecosystem attributes, while leaving few, if any, truly wild places on Earth. Going into the future, scientists can help humanity to domesticate nature more wisely by quantifying the tradeoffs among ecosystem services, such as how increasing the provision of one service may decrease ecosystem resilience and the provision of other services.
Located in
Resources
/
Climate Science Documents
-
Ecologists Report Huge Storm Losses in China’s Forests
-
From delicate orchids and magnolias to rare Chinese yews and Kwangtung pines, the flora of Guangdong
Nanling National Nature Reserve is considered so precious that ecologists call the reserve “a treasure trove of species.” But winter storms have reduced the biological hot spot to a splintered ruin. Snow, sleet, and ice laid waste to 90% of the 58,000- hectare reserve’s forests, says He Kejun, director of Guangdong Forestry
Located in
Resources
/
Climate Science Documents
-
Effects of Climatic Variability and Change on Forest Ecosystems: General Technical Report PNW-GTR-870 December 2012
-
This report is a scientific assessment of the current condition and likely future condition of forest resources in the United States relative to climatic variability and change. It serves as the U.S. Forest Service forest sector technical report for the National Climate Assessment and includes descriptions of key regional issues and examples of a risk-based framework for assessing climate-change effects. By the end of the 21st century, forest ecosystems in the United States will differ from those of today as a result of changing climate. Although increases in temperature, changes in precipitation, higher atmospheric concentrations of carbon dioxide (CO2), and higher nitrogen (N) deposition may change ecosystem structure and function, the most rapidly visible and most significant short-term effects on forest ecosystems will be caused by altered disturbance regimes. For example, wildfires, insect infestations, pulses of erosion and flooding, and drought-induced tree mortality are all expected to increase during the 21st century. These direct and indirect climate-change effects are likely to cause losses of ecosystem services in some areas, but may also improve and expand ecosystem services in others. Some areas may be particularly vulnerable because current infrastructure and resource production are based on past climate and steady-state conditions. The ability of communities with resource-based economies to adapt to climate change is linked to their direct exposure to these changes, as well as to the social and institutional structures present in each environment. Human communities that have diverse economies and are resilient to change today will also be prepared for future climatic stresses.
Located in
Resources
/
Climate Science Documents
-
Effects of Flow Regulation on Shallow-Water Habitat Dynamics and Floodplain Connectivity
-
Our study examined the effects of flow regulation on the spatiotemporal availability of shallow habitat patches with slow current velocity (SSCV patches) and floodplain inundation in the unregulated Yellowstone River and the regulated Missouri River in Montana and North Dakota. We mapped representative sites and used hydraulic models and hydrograph data to describe the frequency and extent of floodplain inundation and the availability of SSCV habitat over time during different water years. In the Yellowstone River the distribution, location, and size of SSCV patches varied but followed an annual pattern that was tied to the snowmelt runoff hydrograph. There was less variation in patch distribution in the Missouri River, and the pattern of habitat availability was influenced by flow regulation. Regulated flows and their effects on channel mor- phology and patterns of vegetation establishment resulted in 3.0–3.5 times less area of inundated woody vegetation during normal and dry years in the Missouri River compared with the Yellow- stone River. The differences we observed in SSCV patch dynamics between rivers may have implications for fish populations and community structure through affecting the survival of early life stages. At a larger scale, the smaller area of vegetation inundated in the Missouri River suggests that nutrient cycling and the ecological benefits associated with a moving littoral zone are reduced by the altered flow and sediment regime in that river. Accurate assessments of the effects of flow alteration and successful efforts to restore riverine ecosystems will require consideration of physical and biotic processes that operate at multiple spatial and temporal scales.
Located in
Resources
/
Climate Science Documents
-
Effects of tree mortality caused by a bark beetle outbreak on the ant community in the San Bernardino National Forest
-
Ants are used as bioindicators of the effects of disturbance on ecosystems for several reasons. First, ants are generally responsive to alteration of the biomass and diversity of the local plant community (Kalif et al., 2001) and other environmental variables (Underwood & Fisher, 2006). Second, because they occupy fixed nest locations, ants are affected by conditions on a very small scale, so that their presence and abundance are a better indicator of local conditions than are the presence or abundance of more mobile animals (Stephens & Wagner, 2006; Underwood & Fisher, 2006). Ants play important ecosystem roles and are therefore often a relevant choice for monitoring (Ho ̈lldobler & Wilson, 1990). They make up a significant percentage of the animal biomass in many ecosystems, they can be crucial to processes such as soil mixing and nutrient transport (Gentry & Stiritz, 1972), and they are important players in nutrient cycling and energy flow. Ants can also strongly influence the plant community via seed dispersal and granivory (Christian, 2001; Barrow et al., 2007). While the diversity of a given taxon is often not a reliable indicator of the diversity of other groups (Lawton et al., 1998; Bennett et al., 2009; Maleque et al., 2009; Wike et al., 2010), ant diversity is known to reflect the diversity of other invertebrates in ecosystems recovering from a disturbance in some cases (Andersen & Majer, 2004).The use of ants as bioindicators must be undertaken with caution (Underwood & Fisher, 2006). Different ant communities do not always respond to a disturbance in the same way (Arnan et al., 2009). In addition, broad measures of a bioindicator taxon, such as species richness or abundance, are potentially misleading. For instance, while it is popular to measure the species richness of bioindicator groups, the ant species richness of different habitats has been observed to respond differently to similar disturbances (Farji-Brener et al., 2002; Ratchford et al., 2005; Barrow et al., 2007), and ant species richness often does not respond at all unless disturbances are extreme (Andersen & Majer, 2004).Nonetheless, changes in the ant community can provide useful information about the responses of the ecosystem as a whole.
Located in
Resources
/
Climate Science Documents
-
Emerging Consensus Shows Climate Change Already Having Major Effects on Ecosystems and Species
-
Plant and animal species are shifting their geographic ranges and the timing of their life events – such as flowering, laying eggs or migrating – at faster rates than researchers documented just a few years ago, according to a technical report on biodiversity and ecosystems used as scientific input for the 2013 Third National Climate Assessment.
Located in
News & Events
-
Fact Sheet: Habitat - Forested Stream and/or Seepage
-
Forested stream environments are typically found in the buffer zones between forested land and stream banks, often known as riparian zones. Stream headwaters and seepage areas occur where ground water percolates to the surface through muck, mossy rock, and nettles. It can also be found under rocks, among gravel, or cobble where water has begun to percolate in areas near open water. Breeding grounds are commonly found beneath mosses growing on rocks, on logs, or soil surfaces in these types of seepage areas.
Located in
Cooperative
/
Publications & Outreach
/
Fact Sheets
-
Fact Sheet: Habitat - Forest/Woodlands
-
Forest/Woodland habitats describe large areas primarily dominated by trees, with moderate ground coverage, such as grasses and shrubs. Density, tree height, and land use may all vary, though woodland is typically used to describe lower density forests. A forest may have an open canopy, but a woodland must have an open canopy with enough sunlight to reach the ground and limited shade.
Located in
Cooperative
/
Publications & Outreach
/
Fact Sheets
-
Fact Sheet: Habitat - Meadows and Marshlands
-
Meadows are open grasslands where grass and other non-woody plants are the primary vegetation. With no tree coverage, meadows are typically open, sunny areas that attract flora and fauna that require both ample space and sunlight. These conditions allow for the growth of many wildflowers and are typically important ecosystems for pollinating insects. Marshlands are like meadows in that they typically have no tree coverage and host primarily grasses and woody plants. However, a defining characteristic of marshlands is their wetland features.
Located in
Cooperative
/
Publications & Outreach
/
Fact Sheets
