Journal of Applied Ecology
SCIE-ISI SCOPUS (1968,1973-2023)
0021-8901
1365-2664
Anh Quốc
Cơ quản chủ quản: Wiley-Blackwell Publishing Ltd , WILEY
Lĩnh vực:
Ecology
Các bài báo tiêu biểu
Assessing the accuracy of species distribution models: prevalence, kappa and the true skill statistic (TSS)Summary
In recent years the use of species distribution models by ecologists and conservation managers has increased considerably, along with an awareness of the need to provide accuracy assessment for predictions of such models. The kappa statistic is the most widely used measure for the performance of models generating presence–absence predictions, but several studies have criticized it for being inherently dependent on prevalence, and argued that this dependency introduces statistical artefacts to estimates of predictive accuracy. This criticism has been supported recently by computer simulations showing that kappa responds to the prevalence of the modelled species in a unimodal fashion. In this paper we provide a theoretical explanation for the observed dependence of kappa on prevalence, and introduce into ecology an alternative measure of accuracy, the true skill statistic (TSS), which corrects for this dependence while still keeping all the advantages of kappa. We also compare the responses of kappa and TSS to prevalence using empirical data, by modelling distribution patterns of 128 species of woody plant in Israel. The theoretical analysis shows that kappa responds in a unimodal fashion to variation in prevalence and that the level of prevalence that maximizes kappa depends on the ratio between sensitivity (the proportion of correctly predicted presences) and specificity (the proportion of correctly predicted absences). In contrast, TSS is independent of prevalence. When the two measures of accuracy were compared using empirical data, kappa showed a unimodal response to prevalence, in agreement with the theoretical analysis. TSS showed a decreasing linear response to prevalence, a result we interpret as reflecting true ecological phenomena rather than a statistical artefact. This interpretation is supported by the fact that a similar pattern was found for the area under the ROC curve, a measure known to be independent of prevalence. Synthesis and applications . Our results provide theoretical and empirical evidence that kappa, one of the most widely used measures of model performance in ecology, has serious limitations that make it unsuitable for such applications. The alternative we suggest, TSS, compensates for the shortcomings of kappa while keeping all of its advantages. We therefore recommend the TSS as a simple and intuitive measure for the performance of species distribution models when predictions are expressed as presence–absence maps.
Tập 43 Số 6 - Trang 1223-1232 - 2006
Trade, transport and trouble: managing invasive species pathways in an era of globalizationSummary
Humans have traded and transported alien species for millennia with two notable step‐changes: the end of the Middle Ages and beginning of the Industrial Revolution. However, in recent decades the world has entered a new phase in the magnitude and diversity of biological invasions: the Era of Globalization. This Special Profile reviews the links between the main drivers of globalization and biological invasions and examines state‐of‐the‐art approaches to pathway risk assessment to illustrate new opportunities for managing invasive species. Income growth is a primary driver of globalization and a clear association exists between Gross Domestic Product and the richness of alien floras and faunas for many regions of the world. In many cases, the exposure of these economies to trade is highlighted by the significant role of merchandise imports in biological invasions, especially for island ecosystems. Post‐1950, technical and logistic improvements have accelerated the ease with which commodities are transported across the globe and hindered the traceability of goods and the ease of intercepting pests. New sea, land and air links in international trade and human transport have established novel pathways for the spread of alien species. Increasingly, the science advances underpinning invasive species management must move at the speed of commerce. Increasing transport networks and demand for commodities have led to pathway risk assessments becoming the frontline in the prevention of biological invasions. The diverse routes of introduction arising from contaminant, stowaway, corridor and unaided pathways, in both aquatic and terrestrial biomes are complex. Nevertheless, common features enable comparable approaches to risk assessment. By bringing together spatial data on climate suitability, habitat availability and points of entry, as well a demographic models that include species dispersal (both natural and human‐mediated) and measures of propagule pressure, it is possible to generate risk maps highlighting potential invasion hotspots that can inform prevention strategies. Synthesis and applications . To date, most attempts to model pathways have focused on describing the likelihood of invader establishment. Few have modelled explicit management strategies such as optimal detection and inspection strategies and assessments of the effectiveness of different management measures. A future focus in these areas will ensure research informs response.
Tập 46 Số 1 - Trang 10-18 - 2009
The Vegetation N:P Ratio: a New Tool to Detect the Nature of Nutrient Limitation
Tập 33 Số 6 - Trang 1441 - 1996
TỔNG QUAN: Một cái nhìn tổng quan về các rủi ro môi trường do thuốc trừ sâu neonicotinoid gây ra Dịch bởi AI Tóm tắt
Các loại thuốc trừ sâu neonicotinoid hiện nay là loại thuốc trừ sâu được sử dụng phổ biến nhất trên toàn thế giới. Chúng có tác dụng hệ thống, đi qua các mô thực vật và bảo vệ tất cả các phần của cây trồng, và thường được áp dụng dưới dạng hạt giống được xử lý. Là những chất độc thần kinh có độ độc cao đối với hầu hết các loài động vật không xương sống, chúng cung cấp khả năng kiểm soát dịch hại hiệu quả và có nhiều ứng dụng trong nông nghiệp canh tác và làm vườn. Tuy nhiên, việc sử dụng phòng ngừa thuốc trừ sâu phổ rộng lại đi ngược lại với những nguyên tắc đã được thiết lập từ lâu của quản lý dịch hại tích hợp (IPM ), dẫn đến những lo ngại về môi trường. Gần đây, người ta phát hiện ra rằng các loại neonicotinoid có thể tồn tại và tích tụ trong đất. Chúng hòa tan trong nước và dễ bị rửa trôi vào các nguồn nước. Vì tính hệ thống của chúng, chúng có mặt trong mật hoa và phấn hoa của các cây trồng được xử lý. Mức độ đã được báo cáo trong đất, nguồn nước, cây cối ở rìa ruộng và tài nguyên hoa có sự chồng chéo lớn với nồng độ đủ để kiểm soát dịch hại trong cây trồng, và thường vượt quá LC 50 (nồng độ gây chết 50% cá thể) cho các sinh vật có lợi. Nồng độ trong mật hoa và phấn hoa của cây trồng đủ để ảnh hưởng đáng kể đến sự sinh sản của các quần thể ong bumblebee. Mặc dù động vật có xương sống ít nhạy cảm hơn so với động vật không xương sống, việc tiêu thụ một số lượng nhỏ hạt giống đã qua xử lý cũng là nguyên nhân gây tử vong trực tiếp ở các loài chim và động vật có vú. Tổng hợp và ứng dụng . Vẫn tồn tại nhiều khoảng trống kiến thức lớn, nhưng việc sử dụng neonicotinoid hiện tại có khả năng đang tác động đến một loạt các nhóm không phải mục tiêu bao gồm các loài thụ phấn và động vật không xương sống trong đất và nước, do đó đe dọa một loạt các dịch vụ hệ sinh thái.
Tập 50 Số 4 - Trang 977-987 - 2013
Post‐war changes in arable farming and biodiversity in Great BritainSummary
Agriculture represents the dominant land use throughout much of western Europe, and a significant part of European biodiversity is associated with this habitat. We attempted to quantify the changes in agriculture and biodiversity in Britain since the 1940s. There have been widespread declines in the populations of many groups of organisms associated with farmland in Britain and north‐west Europe. The declines have been particularly marked amongst habitat specialists; many of the taxa still common on farmland are habitat generalists. Farming practices have become increasingly intensive in the post‐war period, with a dramatic reduction in landscape diversity. Since 1945, there has been a 65% decline in the number of farms, a 77% decline in farm labour and an almost fourfold increase in yield. Farms have become more specialized; the greatly increased use of machinery has made operations quicker and more efficient, but has resulted in the removal of 50% of the hedgerow stock. Autumn sowing of crops has become predominant, with winter stubbles now far less prevalent. The number and extent of chemical applications has increased greatly, but the net amount applied, and their persistence, has decreased in recent years. Intensification has had a wide range of impacts on biodiversity, but data for many taxa are too scarce to permit a detailed assessment of the factors involved. Reduction in habitat diversity was important in the 1950s and 1960s; reduction in habitat quality is probably more important now. As a case study, the declines in populations of seed‐eating birds populations were assessed in relation to changing agricultural management. Generally, the declines were likely to be caused by a reduced food supply in the non‐breeding season, although other factors may be important for particular species. Agriculture will face a number of challenges in the medium term. While research into the mechanisms underlying species and habitat associations, and their interaction with scale, will be critical in under‐pinning management, consideration of farmer attitudes and socio‐economic factors is likely to be as important. Biodiversity may benefit from integrated farming techniques but these need to incorporate environmental objectives explicitly, rather than as a fringe benefit.
Tập 39 Số 1 - Trang 157-176 - 2002
Variation in discrimination factors (Δ15N and Δ13C): the effect of diet isotopic values and applications for diet reconstruction
Tập 46 Số 2 - Trang 443-453 - 2009
A quantitative review of ecosystem service studies: approaches, shortcomings and the road ahead
Tập 48 Số 3 - Trang 630-636 - 2011