Lake Superior ARC Research Habitat Loss 1

Habitat Loss

Browse Research	John Muir Trust study: Impacts of Wind Farms on Upland Habitats
Commentary	Consequences of Habitat Fragmentation Explained through a Simple Experiment
Effects of Habitat Fragmentation on Birds and Mammals in Landscapes with Different Proportions of Suitable Habitat: A Review	Effects of Habitat Fragementation on Biodiversity
Habitat Fragmentation Effects on Birds in Grasslands and Wetlands: A Critique of Our Knowledge (full article)	Diverse and Contrasting Effects of Habitat Fragmentation
Sounding the Depths II: (PDF) The Rising Toll of Sonar, Shipping and Industrial Ocean Noise on Marine Life	Long Point Waterfowl: Importance of the Lower Great Lakes for Waterfowl and the potential impact of Wind Turbine Development. (This is a 9.8MB file so please be patient :-) ) Long Point Waterfowl site Long Point Waterfowl Blog
Low-frequency sounds induce acoustic trauma in cephalopods, Andre et al 2011 View Abstract online View Article online Download PDF	Species–area relationships always overestimate extinction rates from habitat loss

Impacts of Wind Farms on Upland Habitats:
The Environmental Cost of Scotland’s Renewable
Revolution

Commentary

What is Habitat? Habitat, is the natural environment in which an organism lives and evolved in or has adapted to, and the physical environment that surrounds (influences and is utilized by) a species population. While some species range widely through their environment, many have very localized habitats. It is often convenient for those who would exploit the Environment to limit their consideration of a species' or organism's habitat to such a geographically restricted locale. However this ignores the wider influences and dependencies between a habitat and the environment around it, whose existence both influences and buffers it.

For example, a developer who wishes to build a Wind Generating Station in a forested wetland area where Braun's Holly Fern or Oval-leaved Bilberry is found, will be required to protect the immediate surroundings of these plants as they are considered rare and hence a protected species. However, will even a 120 meter setback from development protect these plants when the surrounding forest and watershed is severely disrupted and the drying effect of Industrial Wind Turbines coupled with increased erosion and increased light penetration due to deforestation are significant factors changing the micro climate in the larger surroundings?

The Developer, and the Consultants he pays, will naturally assert that none of these impacts are significant and that there is no danger to the plants. They will even sometimes emplace monitoring and mitigation protocols at the request of the MOE or the MNR.

However the very fact that one has to consider a monitoring protocol implies that there is no certainty at all in their assertions. The adoption of an a priori mitigation strategy is planning for failure. While seemingly sensible and responsible these measures are actually an exercise in avoidance of liability. They can point to these measure and claim that they have done all that a reasonable person (a legal test of liability) could be expected to do.

In that they are only plants or animals or a small ecology, and given the MOE's and MNR's mandates to exploit our natural heritage as efficiently as possible, the developer will be excused as 'it was unforseeable' and allowed to continue with business as usual. We see this exact scenario playing out at Wolfe Island where thousands of birds & bats have been killed by the IWT there. The MNR is 'surprised' and 'concerned' and have accepted the developer's recommendation to 'mitigate' the problem - by studying it further...

It is a carefully orchestrated performance with lots of smoke and mirrors, but it carefully ignores considering one thing: a reasonable person would have foreseen that erecting 132 Industrial Wind Turbines across a major North American migratory bird route would kill thousands of birds. Wind Generating Stations have been killing birds for over 30 years, so I wonder at their surprise.

The same 'planning' and 'stringent environmental protection' is being demonstrated by the MNR and MOE as they approve the Ostrander Point and White Pines Wind Generating Stations which will also be on major bird migratory routes. No doubt they will be 'surprised' and 'concerned' when even more raptors, songbirds and bats are killed at these projects, and tell us, with a straight face, that no one could have forseen the problem.

This calculation of liability and tacit collusion with Government bureaucracies is not new, car companies have done it with gas tanks that explode, vehicles that accelerate rapidly on their own etc... If even 1/10th of the deaths occuring at these IWT were human, the willful blindness to the obvious would be swept away in a tide of indignation and recrimination. However these are only animals and human societies have always exploited and killed those weaker than themselves, especially when it is safe to do so.

The MOE and MNR make grandiose statements about environmental protection, and are quite happy to prosecute private individuals and farmers, but seem less anxious to enforce environmental protection laws and treaties when it would inconvenience big business, especially with the Ontario Government backing Wind Power at all costs.

Government bureaucracies in Canada have a very poor record when it comes to managing ennvironmental protection in the face of Government pressure to facilitate commercial exploitation of a resource. The DFO and the Cod fishery is a perfect example. The same scenario is playing out on the West coast with the Salmon. The MNR's claim to protect bio-diversity is problematic. The MNR doesn't appear to recognize Significant Wildlife Habitat and bio-diversity until it has been reduced to tiny checkerboard enclaves surrounded by development. Here on the Shore of Lake Superior, despite a long history of logging and mining the environment is still largely intact. Yet now the MNR encourages the checkerboarding of this landscape with Wind Generating Stations.

Bio-diversity is impossible to maintain in the face of habitat fragementation. Habitat fragmentation has been shown to lead to the extirpation or extinction of 40% or more of the species that lived in the intact environment. This is not cutting edge science, this is well established and well known to biologists and other natural scientists.

So why are we disturbed about a few dead birds, bats or plants?

Apart from the fact that the creatures we share this planet with have as much right to exist as we do, it is entirely possible that the ecology which supports our existence may well lose its human carrying capacity as a result of losing too many species, not all of which are charismatic mega-fauna.

Even so, the loss of so many species, of places that will henceforth only exist in Group of Seven paintings will surely diminish us.

Consequences of Habitat Fragmentation explained through a simple experiment

Ackerly - The geography of climate change/ implications for conservation biogeography 23 MAR 2010 (Word Document)

Ackerly Climate Change Data Supporting Document (PDF)

Effects of Habitat Fragmentation on Birds and Mammals in Landscapes with Different Proportions of Suitable Habitat: A Review
Henrik Andrén
Oikos
Vol. 71, No. 3 (Dec., 1994), pp. 355-366
(article consists of 12 pages)
Published by: Blackwell Publishing on behalf of Nordic Society Oikos

Abstract
Habitat fragmentation implies a loss of habitat, reduced patch size and an increasing distance between patches, but also an increase of new habitat. Simulations of patterns and geometry of landscapes with decreasing proportion of the suitable habitat give rise to the prediction that the effect of habitat fragmentation on e.g. population size of a species would be primarily through habitat loss in landscape with a high proportion of suitable habitat. However, as the proportion of suitable habitat decreases in the landscape, area and isolation effects start influencing the population size of the species. Hence, the relative importance of pure habitat loss, patch size and isolation are expected to differ at different degrees of habitat fragmentation. This conclusion was supported by a review of studies on birds and mammals in habitat patches in landscapes with different proportions of suitable habitat: the random sample hypothesis was a good predictor of the effects of habitat fragmentation in landscapes with more than 30% of suitable habitat. In these landscapes, habitat fragmentation is primarily habitat loss. However, in landscapes with highly fragmented habitat, patch size and isolation will complement the effect of habitat loss and the loss of species or decline in population size will be greater than expected from habitat loss alone. Habitat patches are parts of the landscape mosaic and the presence of a species in a patch may be a function not only of patch size and isolation, but also of the neighbouring habitat. Habitat generalists may survive in very small patches because they can also utilize resources in the surroundings. Furthermore, the total species diversity across habitats in a given landscape may increase when new patches of habitat are created within the continuous habitat, since new species may be found in these new habitats, even if they are human-made.

EFFECTS OF HABITAT FRAGMENTATION ON BIODIVERSITY
Annual Review of Ecology, Evolution, and Systematics
Vol. 34: 487-515 (Volume publication date November 2003)
First published online as a Review in Advance on August 14, 2003
DOI: 10.1146/annurev.ecolsys.34.011802.132419
Lenore Fahrig
Ottawa-Carleton Institute of Biology, Carleton University, Ottawa, Ontario, Canada K1S 5B6

Abstract
The literature on effects of habitat fragmentation on biodiversity is huge. It is also very diverse, with different authors measuring fragmentation in different ways and, as a consequence, drawing different conclusions regarding both the magnitude and direction of its effects. Habitat fragmentation is usually defined as a landscape-scale process involving both habitat loss and the breaking apart of habitat. Results of empirical studies of habitat fragmentation are often difficult to interpret because (a) many researchers measure fragmentation at the patch scale, not the landscape scale and (b) most researchers measure fragmentation in ways that do not distinguish between habitat loss and habitat fragmentation per se, i.e., the breaking apart of habitat after controlling for habitat loss. Empirical studies to date suggest that habitat loss has large, consistently negative effects on biodiversity. Habitat fragmentation per se has much weaker effects on biodiversity that are at least as likely to be positive as negative. Therefore, to correctly interpret the influence of habitat fragmentation on biodiversity, the effects of these two components of fragmentation must be measured independently. More studies of the independent effects of habitat loss and fragmentation per se are needed to determine the factors that lead to positive versus negative effects of fragmentation per se. I suggest that the term "fragmentation" should be reserved for the breaking apart of habitat, independent of habitat loss.

Habitat Fragmentation Effects on Birds in Grasslands and Wetlands: A Critique of Our Knowledge (full article)
Douglas H. Johnson

Abstract
Habitat fragmentation exacerbates the problem of habitat loss for grassland and wetland birds. Remaining patches of grasslands and wetlands may be too small, too isolated, and too influenced by edge effects to maintain viable populations of some breeding birds. Knowledge of the effects of fragmentation on bird populations is critically important for decisions about reserve design, grassland and wetland management, and implementation of cropland set-aside programs that benefit wildlife. In my review of research that has been conducted on habitat fragmentation, I found at least five common problems in the methodology used. The results of many studies are compromised by these problems: passive sampling (sampling larger areas in larger patches), confounding effects of habitat heterogeneity, consequences of inappropriate pooling of data from different species, artifacts associated with artificial nest data, and definition of actual habitat patches. As expected, some large-bodied birds with large territorial requirements, such as the northern harrier (Circus cyaneus), appear area sensitive. In addition, some small species of grassland birds favor patches of habitat far in excess of their territory size, including the Savannah (Passerculus sandwichensis), grasshopper (Ammodramus savannarum) and Henslow's (A. henslowii) sparrows, and the bobolink (Dolichonyx oryzivorus). Other species may be area sensitive as well, but the data are ambiguous. Area sensitivity among wetland birds remains unknown since virtually no studies have been based on solid methodologies. We need further research on grassland bird response to habitat that distinguishes supportable conclusions from those that may be artifactual.

Key Words: birds, fragmentation, grasslands, habitat, wetlands, wildlife

Diverse and Contrasting Effects of Habitat Fragmentation

    George R. Robinson,
    Robert D. Holt,
    Michael S. Gaines,
    Steven P. Hamburg,
    Michael L. Johnson,
    Henry S. Fitch and
    Edward A. Martinko

    Department of Biological Sciences, Rutgers University, Piscataway, NJ 08855
    Department of Systematics and Ecology and Museum of Natural History, University of Kansas, Lawrence, KS 66045
    Department of Systematics and Ecology, University of Kansas, Lawrence, KS 66045
    Department of Systematics and Ecology and Environmental Studies Program, University of Kansas, Lawrence, KS 66045

Science 24 July 1992:
Vol. 257 no. 5069 pp. 524-526
DOI: 10.1126/science.257.5069.524

Abstract
Different components of an ecosystem can respond in very different ways to habitat fragmentation. An archipelago of patches, representing different levels of fragmentation, was arrayed within a successional field and studied over a period of 6 years. Ecosystem processes (soil mineralization and plant succession) did not vary with the degree of subdivision, nor did most measures of plant and animal community diversity. However, fragmentation affected vertebrate population dynamics and distributional patterns as well as the population persistence of clonal plant species. The results highlight the dangers of relying on broad community measures in lieu of detailed population analyses in studies of fragmented habitats.

DEMOGRAPHIC EFFECTS OF HABITAT FRAGMENTATION ON A TROPICAL HERB: LIFE-TABLE RESPONSE EXPERIMENTS

Emilio M. Bruna^1,2 and Madan K. Oli¹

1 Department of Wildlife Ecology and Conservation, University of Florida, Gainesville, Florida 32611-0430 USA
2 Tropical Conservation and Development Program, Center for Latin American Studies, University of Florida, Gainesville, Florida 32611-5530 USA

Ecology 86:1816–1824. [doi:10.1890/04-1716]

Abstract
Habitat fragmentation is a leading cause of extinction, with effects that may be particularly pronounced in tropical ecosystems. However, little is known regarding the demographic mechanisms underlying changes in abundance in fragmented landscapes. Using six years of demographic data collected from >6600 individuals of the Amazonian understory herb Heliconia acuminata, we calculated population growth rate (λ) in experimentally isolated 10-ha forest fragments, 1-ha forest fragments, and continuous forest. We then used life-table response experiment analyses to elucidate the mechanisms responsible for observed differences in λ. On average, λ ≈ 1.05 in continuous forest, while λ ≈ 1 in both 1-ha and 10-ha fragments. However, while the differences in λ between 10-ha fragments and continuous forest were largely attributable to the negative contribution of stage-specific fertility rates, reduced λ in 1-ha fragments was due to both reductions in reproductive rates and changes in the rate of plant growth. Our results show that similar reductions in λ in fragments of different sizes can be driven by distinct demographic mechanisms. Without comprehensive demographic data, attempts to mitigate the decline of populations in fragmented landscapes could be unsuccessful because they might be focusing on inappropriate demographic targets.

Keywords: Amazon, deforestation, Heliconia acuminata, Heliconiaceae, life table response experiment, LTRE, matrix models, population growth rate, lambda, sensitivity analysis

Received: November 14, 2004; Revised: November 30, 2004; Accepted: December 1, 2004

SOUNDING THE DEPTHS II: (PDF)
The Rising Toll of Sonar, Shipping and Industrial Ocean Noise on Marine Life
Principal Author
Michael Jasny
Coauthors
Joel Reynolds Cara Horowitz Andrew Wetzler
Project Director
Joel Reynold

Species–area relationships always overestimate extinction rates from habitat loss                     (Read AFP article about the study)

    Fangliang He1, 2
    Stephen P. Hubbell3, 4

    Nature 473, 368–371
    (19 May 2011)
    doi:10.1038/nature09985

Received
    21 December 2010
Accepted
    08 March 2011
Published online
    18 May 2011

Extinction from habitat loss is the signature conservation problem of the twenty-first century1. Despite its importance, estimating extinction rates is still highly uncertain because no proven direct methods or reliable data exist for verifying extinctions. The most widely used indirect method is to estimate extinction rates by reversing the species–area accumulation curve, extrapolating backwards to smaller areas to calculate expected species loss. Estimates of extinction rates based on this method are almost always much higher than those actually observed2, 3, 4, 5. This discrepancy gave rise to the concept of an ‘extinction debt’, referring to species ‘committed to extinction’ owing to habitat loss and reduced population size but not yet extinct during a non-equilibrium period6, 7. Here we show that the extinction debt as currently defined is largely a sampling artefact due to an unrecognized difference between the underlying sampling problems when constructing a species–area relationship (SAR) and when extrapolating species extinction from habitat loss. The key mathematical result is that the area required to remove the last individual of a species (extinction) is larger, almost always much larger, than the sample area needed to encounter the first individual of a species, irrespective of species distribution and spatial scale. We illustrate these results with data from a global network of large, mapped forest plots and ranges of passerine bird species in the continental USA; and we show that overestimation can be greater than 160%. Although we conclude that extinctions caused by habitat loss require greater loss of habitat than previously thought, our results must not lead to complacency about extinction due to habitat loss, which is a real and growing threat.
Subject terms:

Figures at a glance

    Figure 1: Sampling differences for SAR and EAR.

Range distribution of a species (blue area), and an arbitrary starting sample point, indicated by +. Regardless of the starting location, a sampling frame of arbitrary shape (here circular) with an area of a size sufficient to contact the species for the first time is always less than the sample area needed to encompass the entire range of the species. The SAR (species accumulation) is constructed from sample areas of first contact, and the EAR (species extinction) is constructed from areas of last contact.
Figure 2: Species– and endemics–area curves for six of the nine data sets in Table 1.

The second and fourth columns are the plots on a log–log scale. The upper and lower blue curves are the fits of the power-law SAR and EAR (equation (3)), respectively. The upper and lower red curves are the predictions of the random placement SAR (equation (1)) and EAR (equation (2)), respectively. Unlike for the other data sets, the red curve for US passerine data (cell size 0.48° latitude × 0.48° longitude) is the fit of equation (3) because the abundances of the passerine species are not known (so equation (2) cannot be used). The cloud of points represent 100 repeated random samples of the SAR and EAR. The SAR and EAR curves for the Barro Colorado Island plot are shown in Supplementary Fig. 1.