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Whitton 1984.pdf
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WAT-WIL
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Why a collapse of global civilization will be avoided: a comment on Ehrlich & Ehrlich
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1st paragraph: Ehrlich FRS & Ehrlich [1] claim that over-population, over-consumption and the future climate mean that ‘preventing a global collapse of civilization is perhaps the foremost challenge confronting humanity’. What is missing from the well- referenced perspective of the potential downsides for the future of humanity is any balancing assessment of the progress being made on these three chal- lenges (and the many others they cite by way of detail) that suggests that the problems are being dealt with in a way that will not require a major disruption to the human condition or society. Earlier dire predictions have been made in the same mode by Malthus FRS [2] on food security, Jevons FRS [3] on coal exhaustion, King FRS & Murray [4] on peak oil, and by many others. They have all been overcome by the exercise of human ingenuity just as the doom was being prophesied with the deployment of steam engines to greatly improve agricultural efficiency, and the discoveries of oil and of fracking oil and gas, respectively, for the three examples given. It is incumbent on those who would continue to predict gloom to learn from history and make a comprehen- sive review of human progress before coming to their conclusions. The problems as perceived today by Ehrlich FRS and Ehrlich will be similarly seen off by work in progress by scientists and engineers. My comment is intended to summarize and reference the potential upsides being produced by today’s human ingenuity, and I leave the reader to weigh the balance for the future, taking into account the lessons of recent history.
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WHY FORESTS ARE PIVOTAL IN PLANNING FOR CLIMATE CHANGE
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17 slides show carbon-forest relationships including logging and carbon in US forests
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Why Is Climate Sensitivity So Unpredictable?
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Uncertainties in projections of future climate change have not lessened substantially in past
decades. Both models and observations yield broad probability distributions for long-term
increases in global mean temperature expected from the doubling of atmospheric carbon dioxide,
with small but finite probabilities of very large increases. We show that the shape of these
probability distributions is an inevitable and general consequence of the nature of the climate
system, and we derive a simple analytic form for the shape that fits recent published distributions
very well. We show that the breadth of the distribution and, in particular, the probability of
large temperature increases are relatively insensitive to decreases in uncertainties associated with
the underlying climate processes.
VOL 318 26 OCTOBER 2007
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Why Landscape Conservation Planning
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An overview on the major environmental challenges of today and the need to shift conservation towards a larger, more comprehensive scale that protects species, habitats and ecosystems in interconnected landscapes through strategic conservation planning.
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Overview: Science Investments
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Why Landscape Planning & Design Approach?
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Overview: Science Investments
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Widespread crown condition decline, food web disruption, and amplified tree mortality with increased climate change-type drought
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Climate change is progressively increasing severe drought events in the Northern Hemisphere, causing regional tree die-off events and contributing to the global reduction of the carbon sink efficiency of forests. There is a critical lack of integrated community- wide assessments of drought-induced responses in forests at the macroecological scale, including defoliation, mortality, and food web responses. Here we report a generalized increase in crown defoliation in southern European forests occurring during 1987– 2007. Forest tree species have consistently and significantly altered their crown leaf structures, with increased percentages of defolia- tion in the drier parts of their distributions in response to increased water deficit. We assessed the demographic responses of trees associated with increased defoliation in southern European forests, specifically in the Iberian Peninsula region. We found that defolia- tion trends are paralleled by significant increases in tree mortality rates in drier areas that are related to tree density and temperature effects. Furthermore, we show that severe drought impacts are associated with sudden changes in insect and fungal defoliation dynamics, creating long-term disruptive effects of drought on food webs. Our results reveal a complex geographical mosaic of species- specific responses to climate change–driven drought pressures on the Iberian Peninsula, with an overwhelmingly predominant trend toward increased drought damage.
extreme events | earth system feedbacks | ecological networks | global change | Mediterranean biome
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Widlak 1987.pdf
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WAT-WIL
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Widlak 1993.pdf
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Wild Pollinators Enhance Fruit Set of Crops Regardless of Honey Bee Abundance
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The diversity and abundance of wild insect pollinators have declined in many agricultural landscapes. Whether such declines reduce crop yields, or are mitigated by managed pollinators such as honey bees, is unclear. We found universally positive associations of fruit set with flower visitation by wild insects in 41 crop systems worldwide. In contrast, fruit set increased significantly with flower visitation by honey bees in only 14% of the systems surveyed. Overall, wild insects pollinated crops more effectively; an increase in wild insect visitation enhanced fruit set by twice as much as an equivalent increase in honey bee visitation. Visitation by wild insects and honey bees promoted fruit set independently, so pollination by managed honey bees supplemented, rather than substituted for, pollination by wild insects. Our results suggest that new practices for integrated management of both honey bees and diverse wild insect assemblages will enhance global crop yields.
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