生态预报: 生态学的一个前沿领域

生态预报对于资源,环境的决策和管理将起着越来越重要的作用。计算机科学和定量分析的进步,生态学理论的发展以及新技术的应用增加了人类预测生态系统变化的能力。本文介绍了有关生态预报的内涵,相关研究进展及案例,提出生态预报是生态学的一个重要前沿领域,也将是今后生态学研究的一个重要努力方向。     

Using ecological networks to answer questions in global biogeography and ecology

Ecological networks have classically been studied at site and landscape scales, yet recent efforts have been made to collate these data into global repositories. This offers an opportunity to integrate and upscale knowledge about ecological interactions from local to global scales to gain enhanced insights from the mechanistic information provided by these data. By drawing on existing research investigating patterns in ecological interactions at continental to global scales, we show how data on ecological networks, collected at appropriate scales, can be used to generate an improved understanding of many aspects of ecology and biogeography—for example, species distribution modelling, restoration ecology and conservation. We argue that by understanding the patterns in the structure and function of ecological networks across scales, it is possible to enhance our understanding of the natural world.     

Managing data locally to answer questions globally: The role of collaborative science in ecology

Ecologists are increasingly asking large‐scale and/or broad‐scope questions that require vast datasets. In response, various top‐down efforts and incentives have been implemented to encourage data sharing and integration. However, despite general consensus on the critical need for more open ecological data, several roadblocks still discourage compliance and participation in these projects; as a result, ecological data remain largely unavailable. Grassroots initiatives (i.e. efforts initiated and led by cohesive groups of scientists focused on specific goals) have thus far been overlooked as a powerful means to meet these challenges. These bottom‐up collaborative data integration projects can play a crucial role in making high quality datasets available because they tackle the heterogeneity of ecological data at a scale where it is still manageable, all the while offering the support and structure to do so. These initiatives foster best practices in data management and provide tangible rewards to researchers who choose to invest time in sound data stewardship. By maintaining proximity between data generators and data users, grassroots initiatives improve data interpretation and ensure high‐quality data integration while providing fair acknowledgement to data generators. We encourage researchers to formalize existing collaborations and to engage in local activities that improve the availability and distribution of ecological data. By fostering communication and interaction among scientists, we are convinced that grassroots initiatives can significantly support the development of global‐scale data repositories. In doing so, these projects help address important ecological questions and support policy decisions.     

Renewable fuels from algae: An answer to debatable land based fuels

This article reviews the utilization of first and second-generation biofuels as the suitable alternatives to depleting fossil fuels. Then the concern has been presented over a debate on most serious problem arising from the production of these biofuels; which is the increase of food market prices because of the increased use of arable land for the cultivation of biomass used for the production of first and second-generation biofuels. The solution to this debate has been suggested with the use of non-arable land for the cultivation of algal biomass for the generation of third generation biofuels. The recent research and developments in the cultivation of algal biomass and their use for biofuel production have been discussed.     

An answer to a complex problem: cloning the mouse t-complex responder

The t-complex is maintained in wild mouse populations by its high transmission (up to 99%) from heterozygous males and provides an example of ``meiotic drive'. Its molecular basis has remained obscure despite long and intensive study. In a major advance, the t-complex responder gene, thought to be the key gene on which several distorters act, has now been cloned. Received: 14 April 2000 / Accepted: 4 May 2000     

Honeyeater ecology: An introduction

Abstract

Nectar-feeding birds are often used for testing quantitative models but most of this work has been done on groups in the Northern Hemisphere and only recently have workers turned their attention to honeyeaters (Meliphagidae). Predictions of upper size limits derived from North America appear inappropriate and possible reasons for this are discussed. One; the suggested evolutionary links between nectar-feeding birds and their flowers, may not be as close for honeyeaters but further work is needed. Other aspects such as research on community and social relationships among honeyeaters appears rewarding but little is known.

We caution workers on expecting agreement with wide generalisations in any topic because of known variability in movements and diet in different areas and for different individuals.     

Circumventing structural uncertainty: A Bayesian perspective on nonlinear forecasting for ecology

As a consequence of the complexity of ecosystems and context-dependence of species interactions, structural uncertainty is pervasive in ecological modeling. This is particularly problematic when ecological models are used to make conservation and management plans whose outcomes may depend strongly on model formulation. Nonlinear time series approaches allow us to circumvent this issue by using the observed dynamics of the system to guide policy development. However, these methods typically require long time series from stationary systems, which are rarely available in ecological settings. Here we present a Bayesian approach to nonlinear forecasting based on Gaussian processes that readily integrates information from several short time series and allows for nonstationary dynamics. We demonstrate the utility of our modeling methods on simulated from a wide range of ecological scenarios. We expect that these models will extend the range of ecological systems to which nonlinear forecasting methods can be usefully applied.     

The grand challenges of migration ecology that radar aeroecology can help answer

Many migratory species have experienced substantial declines that resulted from rapid and massive expansions of human structures and activities, habitat alterations and climate change. Migrants are also recognized as an integral component of biodiversity and provide a multitude of services and disservices that are relevant to human agriculture, economy and health. The plethora of recently published studies reflects the need for better fundamental knowledge on migrations and for better management of their ecological and human‐relevant effects. Yet, where are we in providing answers to fundamental questions and societal challenges? Engaging a broad network of researchers worldwide, we used a horizon‐scan approach to identify the most important challenges which need to be overcome in order to gain a fuller understanding of migration ecology, and which could be addressed using radar aeroecological and macroecological approaches. The top challenges include both long‐standing and novel topics, ranging from fundamental information on migration routes and phenology, orientation and navigation strategies, and the multitude of effects migrants may have on resident communities, to societal challenges, such as protecting or preventing migrant services and disservices, and the conservation of migrants in the face of environmental changes. We outline these challenges, identify the urgency of addressing them and the primary stakeholders – researchers, policy makers and practitioners, or funders of research.     

Biology of cancer: some questions to answer

Though great advances in cancer biology have taken place through these years, some fundamental questions are still to be explained. Some observations in this regard are discussed in the present paper. In the course of experimental studies on hormonal stimulation of target cells, it was observed that goat granulosa cells showed differential proliferative response to sustained stimulation by oLH and hCG in culture. oLH caused cells to proliferate whereas hCG failed to stimulate the cells though both the gonadotropins have common receptors on the target cell. Further studies might throw some light on the mechanism of signal transduction in cell biology and neoplasia. A question is also posed as to how to interpret thermodynamically the sustained growth of cancer vis-a-vis the host.     

Some theoretical considerations: From landscape ecology to waterscape ecology

Being inspired in the process of teaching and studying on tourism geography and heritage landscapes, the author attempts to broaden the scope of traditional studies in landscape ecology. Upon reviewing the progress, limitations and boundaries of landscape ecology, he criticizes the negligence of waterscapes by academics. The author further examines some waterscape conservation policy programs practiced by different nations. These include 10 National Seashores, 4 National Lakeshores, 4 National Rivers, 13 National Marine Sanctuaries and 1 Marine National Monument in USA, 13 Marine National Parks, 11 Marine Sanctuaries and 4 multiple use Marine Reserves in the State of Victoria, Australia, 3 Marine Nature Reserves and 43 Heritage Coasts in UK, and 272 National Water Parks in China. Based on these explorations, the author proposes a few hypotheses on waterscape ecology. Finally, he concludes that as one among many sub-disciplines of applied ecology, waterscape ecology can only achieve its full-fledged growth through concerted efforts among academics, and the supports from both governments and non-government organizations. Meanwhile, the site-specific policy practices with the rapid increasing social needs will likely facilitate the development of this infant school. Hopefully, the birth and development of waterscape ecology will contribute to the prosperity of global academics and the maintenance of earth level environmental health.     

Some theoretical considerations: From landscape ecology to waterscape ecology

Being inspired in the process of teaching and studying on tourism geography and heritage landscapes, the author attempts to broaden the scope of traditional studies in landscape ecology. Upon reviewing the progress, limitations and boundaries of landscape ecology, he criticizes the negligence of waterscapes by academics. The author further examines some waterscape conservation policy programs practiced by different nations. These include 10 National Seashores, 4 National Lakeshores, 4 National Rivers, 13 National Marine Sanctuaries and 1 Marine National Monument in USA, 13 Marine National Parks, 11 Marine Sanctuaries and 4 multiple use Marine Reserves in the State of Victoria, Australia, 3 Marine Nature Reserves and 43 Heritage Coasts in UK, and 272 National Water Parks in China. Based on these explorations, the author proposes a few hypotheses on waterscape ecology. Finally, he concludes that as one among many sub-disciplines of applied ecology, waterscape ecology can only achieve its full-fledged growth through concerted efforts among academics, and the supports from both governments and non-government organizations. Meanwhile, the site-specific policy practices with the rapid increasing social needs will likely facilitate the development of this infant school. Hopefully, the birth and development of waterscape ecology will contribute to the prosperity of global academics and the maintenance of earth level environmental health.     

Plant physiological ecology: An essential link for integrating across disciplines and scales in plant ecology

A sizeable number of scientists and funding organisations are of the opinion that the relevance of plant physiological ecology as an important discipline has declined to the point that it is no longer considered as one of the important topics of ecological research. Plant physiological ecology is typically associated with the autecological plant research conducted during the latter portion of the 20th century or, even worse, simply with gas exchange measurements. However, taking a closer look, it becomes obvious that, by focusing on the intermediate integration levels (individuals, populations), this discipline represents an essential link between the high integration levels (communities, ecosystems, biosphere) and the disciplines at the bottom of the complexity hierarchy (physiology, molecular biology). In this paper we show that the principal question of all ongoing community and ecosystem level research – What is the mechanistic background of vegetation composition, biodiversity structure and dynamics and how is this linked to fluxes of matter at the community and higher levels of organisation? – can only be answered if the mechanism of interactions between the relevant organisms are understood. In consequence, the classical discipline of plant physiological ecology will continuously develop into a truly interdisciplinary experimental ecology of interactions and its importance will rather increase than diminish. Promising activities of this kind are already underway. Scientists needed for this new direction should have a rather broad scientific perspective, including knowledge and experience in fields outside of typical ecological research, instead of being specialists for single ecophysiological aspects.     

An approach to multi-class imbalanced problem in ecology using machine learning

Ecologists collect their data manually by visiting multiple sampling sites. Since there can be multiple species in the multiple sampling sites, manually classifying them can be a daunting task. Much work in literature has focused mostly on statistical methods for classification of single species and very few studies on classification of multiple species. In addition to looking at multiple species, we noted that classification of multiple species result in multi-class imbalanced problem. This study proposes to use machine learning approach to classify multiple species in population ecology. In particular, bagging (random forests (RF) and bagging classification trees (bagCART)) and boosting (boosting classification trees (bootCART), gradient boosting machines (GBM) and adaptive boosting classification trees (AdaBoost)) classifiers were evaluated for their performances on imbalanced multiple fish species dataset. The recall and F1-score performance metrics were used to select the best classifier for the dataset. The bagging classifiers (RF and bagCART) achieved high performances on the imbalanced dataset while the boosting classifiers (bootCART, GBM and AdaBoost) achieved lower performances on the imbalanced dataset. We found that some machine learning classifiers were sensitive to imbalanced dataset hence they require data resampling to improve their performances. After resampling, the bagging classifiers (RF and bagCART) had high performances compared to boosting classifiers (bootCART, GBM and AdaBoost). The strong performances shown by bagging classifiers (RF and bagCART) suggest that they can be used for classifying multiple species in ecological studies.     

Plant synthetic biology: One answer to global challenges

正In times of climate change, population growth and resource depletion, the future well-being of mankind will greatly depend on the ability to breed/engineer crop plants for high yield, low input and high quality.Based on the evaluation of historical yield increases, it seems that yield of major grain crops, such as rice or