Identifying germination opportunities for threatened plant species in episodic ecosystems by linking germination profiles with historic rainfall events

2019 ◽  
Vol 67 (3) ◽  
pp. 256 ◽  
Author(s):  
Carole P. Elliott ◽  
Wolfgang Lewandrowski ◽  
Ben P. Miller ◽  
Matthew Barrett ◽  
Shane R. Turner

Dynamic processes of seed germination, influenced by niche–climate interactions, underpin successful seedling establishment. For threatened species with niches restricted to specific landforms, such as Banded Ironstone Formations (BIF), understanding germination opportunities in relation to long-term rainfall patterns can be critical for management. We quantified germination profiles (germinating fraction and speed with varying dormancy states) from six taxonomically diverse threatened species that are endemic to BIF in Western Australia, and related this to historic rainfall patterns and events. The upper limit of the germination profiles (i.e. for dormancy-alleviated seed) was 1.2–60 times higher (germinating fraction; Gmax) and 1.1–4 times faster (T10) than the lower profile limit (i.e. dormancy not alleviated) in the physiologically dormant species studied (Tetratheca paynterae Alford subsp. paynterae and T. erubescens J.P.Bull; Ricinocarpos brevis R.J.F.Hend. & Mollemans; Darwinia masonii C.A.Gardner; Lepidosperma gibsonii R.L.Barrett). Seeds of Banksia arborea (C.A.Gardner) A.R.Mast & K.R.Thiele are non-dormant and had a germination profile similar to this upper limit. The minimum period of moisture required for germination was less than eight consecutive days and our simple moisture model, based on historic rainfall patterns for their localities, indicated that these periods have likely occurred 16 times in the last 100 years. We suggest that these BIF species are likely committing to germination during heightened rainfall periods, despite these periods being infrequent and irregular. Understanding the germination profiles of range-restricted species provides important insights into the environmental filters regulating recruitment and supports the development of more effective management and conservation approaches for protecting these species.

Oryx ◽  
2019 ◽  
Vol 53 (3) ◽  
pp. 429-435 ◽  
Author(s):  
Juan C. Álvarez-Yépiz ◽  
Alberto Búrquez ◽  
Angelina Martínez-Yrízar ◽  
Martin Dovciak

AbstractTraditionally the vulnerability of threatened species to extinction has been assessed by studying their environment, genetics and population dynamics. A more comprehensive understanding of the factors promoting or limiting the long-term persistence of threatened species could be achieved by conducting an analysis of their functional responses to changing environments, their ecological interactions, and their role in ecosystem functioning. These less traditional research areas can be unified in a trait-based approach, a recent methodological advance in ecology that is being used to link individual-level functions to species, community and ecosystem processes to provide mechanistic explanations of observed patterns, particularly in changing environments. We illustrate how trait-based information can be translated into well-defined conservation strategies, using the example of Dioon sonorense, an Endangered cycad endemic to north-western Mexico. Scientific information yielded by trait-based research, coupled with existing knowledge derived from well-established traditional approaches, could facilitate the development of more integrative conservation strategies to promote the long-term persistence of individual threatened species. A comprehensive database of functional traits of threatened species would be of value in assisting the implementation of the trait-based approach.


Author(s):  
Mostafa A. Mohamed ◽  
Mohamed El-Sayed El-Mahdy

Abstract The relation between sunspots and rainfall patterns is still obscure in Africa, especially for Sudan and South Sudan. This research explores the response of rainfall to solar activity in eastern regions of Africa, with a case study in Sudan and South Sudan. Rainfall varies with time; therefore, skillful monitoring, predicting, and early warning of rainfall events is indispensable. Severe climatic events, such as droughts and floods, are critical factors in planning and managing all socioeconomic activities. Similar trends for the sunspot activity (sunspot number and sunspot groups) changes and rainfall variations for different stations in East Africa during the years 1910–2018 were not found. Correlation analysis carried out for the above period indicated a weak negative correlation between the total rainfall and the average number of sunspots over the long-term scale for selected stations in Sudan and South Sudan. The overall result of the paper indicated no significant relationship between sunspot numbers and rainfall in temporal and spatial scales in Sudan and South Sudan.


1984 ◽  
Vol 16 (8-9) ◽  
pp. 131-138 ◽  
Author(s):  
Johannes Brummer

Problems in the construction of design storms are expressed in mathematical terms. Introduced here is a concept for approximating natural peak flow values by means of the distribution of typical rainfall patterns. A comparison demonstrates the quality of this concept and the competency of some well-known design storms for the adequate evaluation of peak flows.


Polar Record ◽  
2021 ◽  
Vol 57 ◽  
Author(s):  
Frigga Kruse ◽  
Gary R. Nobles ◽  
Martha de Jong ◽  
Rosanne M. K. van Bodegom ◽  
G. J. M. (Gert) van Oortmerssen ◽  
...  

Abstract Arctic mining has a bad reputation because the extractive industry is often responsible for a suite of environmental problems. Yet, few studies explore the gap between untouched tundra and messy megaproject from a historical perspective. Our paper focuses on Advent City as a case study of the emergence of coal mining in Svalbard (Norway) coupled with the onset of mining-related environmental change. After short but intensive human activity (1904–1908), the ecosystem had a century to respond, and we observe a lasting impact on the flora in particular. With interdisciplinary contributions from historical archaeology, archaeozoology, archaeobotany and botany, supplemented by stable isotope analysis, we examine 1) which human activities initially asserted pressure on the Arctic environment, 2) whether the miners at Advent City were “eco-conscious,” for example whether they showed concern for the environment and 3) how the local ecosystem reacted after mine closure and site abandonment. Among the remains of typical mining infrastructure, we prioritised localities that revealed the subtleties of long-term anthropogenic impact. Significant pressure resulted from landscape modifications, the import of non-native animals and plants, hunting and fowling, and the indiscriminate disposal of waste material. Where it was possible to identify individual inhabitants, these shared an economic attitude of waste not, want not, but they did not hold the environment in high regard. Ground clearances, animal dung and waste dumps continue to have an effect after a hundred years. The anthropogenic interference with the fell field led to habitat creation, especially for vascular plants. The vegetation cover and biodiversity were high, but we recorded no exotic or threatened plant species. Impacted localities generally showed a reduction of the natural patchiness of plant communities, and highly eutrophic conditions were unsuitable for liverworts and lichens. Supplementary isotopic analysis of animal bones added data to the marine reservoir offset in Svalbard underlining the far-reaching potential of our multi-proxy approach. We conclude that although damaging human–environment interactions formerly took place at Advent City, these were limited and primarily left the visual impact of the ruins. The fell field is such a dynamic area that the subtle anthropogenic effects on the local tundra may soon be lost. The fauna and flora may not recover to what they were before the miners arrived, but they will continue to respond to new post-industrial circumstances.


2011 ◽  
Vol 24 (7) ◽  
pp. 1913-1921 ◽  
Author(s):  
Mateus da Silva Teixeira ◽  
Prakki Satyamurty

Abstract A new approach to define heavy and extreme rainfall events based on cluster analysis and area-average rainfall series is presented. The annual frequency of the heavy and extreme rainfall events is obtained for the southeastern and southern Brazil regions. In the 1960–2004 period, 510 (98) and 466 (77) heavy (extreme) rainfall events are identified in the two regions. Monthly distributions of the events closely follow the monthly climatological rainfall in the two regions. In both regions, annual heavy and extreme rainfall event frequencies present increasing trends in the 45-yr period. However, only in southern Brazil is the trend statistically significant. Although longer time series are necessary to ensure the existence of long-term trends, the positive trends are somewhat alarming since they indicate that climate changes, in terms of rainfall regimes, are possibly under way in Brazil.


2002 ◽  
Vol 50 (1) ◽  
pp. 1 ◽  
Author(s):  
Mark A. Burgman

Despite the fact that the most changes in lists of threatened species reflect changes in knowledge rather than changes in conservation status, the lists continue to provide social and legal mandates for conservation; they are used to report on the state of the environment and to guide the allocation of scarce resources. There is a substantial under-representation of non-vascular species in threatened plant lists, reflected in an absence of documented extinctions among fungi and algae. Turnover in the composition of extinct flora lists in Australia suggests that the lists of threatened species may not be sufficiently reliable to form the basis for reporting on the state of the environment. They are of limited use in distinguishing between levels of threat and may not be a reliable guide for the allocation of scarce conservation resources among plant species. Systems for listing threatened species create a feedback loop, responsive to the subjective preferences of scientists, largely unresponsive to underlying true threats, self-perpetuating and accentuating bias with each iteration. Other tools, including formal decision approaches and the acquisition of new kinds of data, are needed to fill the roles.


2021 ◽  
Vol 13 (13) ◽  
pp. 7193
Author(s):  
Jiyeon Choi ◽  
Baekyung Park ◽  
Jinsun Kim ◽  
Soyoung Lee ◽  
Jichul Ryu ◽  
...  

This study aimed to estimate pollutant unit loads for different landuses and pollutants that reflected long-term runoff characteristics of nonpoint source (NPS) pollutants and recent environmental changes. During 2008–2014, 2026 rainfall events were monitored. The average values of antecedent dry days, total rainfall, rainfall intensity, rainfall duration, runoff duration, and runoff coefficient for each landuse were 3.8–5.9 d, 35.2–65.0 mm, 2.9–4.1 mm/h, 12.5–20.4 h, 12.4–27.9 h, and 0.24–0.45, respectively. Uplands (UL) exhibited high suspended solids (SS, 606.2 mg/L), total nitrogen (TN, 7.38 mg/L), and total phosphorous (TP, 2.27 mg/L) levels, whereas the runoff coefficient was high in the building sites (BS), with a high impervious surface ratio. The event mean concentration (EMC) for biological oxygen demand (BOD) was the highest in BS (8.0 mg/L), while the EMC was the highest in BS (in the rainfall range <10 mm) and UL and forest land (in the rainfall range >50 mm). The unit loads for BOD (1.49–17.76 kg/km2·d), TN (1.462–10.147 kg/km2·d), TP (0.094–1.435 kg/km2·d), and SS (15.20–327.70 kg/km2·d) were calculated. The findings can be used to manage NPS pollutants and watershed environments and implement relevant associated management systems.


2021 ◽  
Author(s):  
Kathryn Powlen ◽  
Kelly W. Jones ◽  
Elva Ivonne Bustamante Moreno ◽  
Maira Abigail Ortíz Cordero ◽  
Jennifer N. Solomon ◽  
...  

Protected areas (PAs) are under immense pressure to safeguard much of the world’s remaining biodiversity and can be strained by unpredicted events such as the COVID-19 pandemic. Understanding the extent of the pandemic on PA inputs, mechanisms, and conservation outcomes is critical for recovery and future planning to buffer against these types of events. We use survey and focus group data to quantify the impact of the pandemic on Mexico’s PA network and outline the pathways that led to conservation outcomes. On average, across 62 PAs, we find substantial changes in management capacity, monitoring, and tourism, and a slight increase in non-compliant activities. Our findings highlight the need to increase short-term relief efforts and long-term livelihood diversification initiatives for communities dependent on tourism, who were most vulnerable during the pandemic. Increased management support, including technical capacity and financial resources, could also better sustain management activities in future shocks.


2017 ◽  
Vol 50 (1) ◽  
pp. 155-165 ◽  
Author(s):  
Yanyan Cheng ◽  
Guotao Cui ◽  
Jianting Zhu

Abstract Understanding infiltration into soils from rainfall events is important for many practical applications. The idea of time compression approximation (TCA) was proposed to simulate infiltration rate, which only requires the relationship between the potential infiltration rate (PIR) and potential cumulative infiltration (PCI). The TCA-based method can be used in any rainfall–runoff models since the PIR vs. PCI relationship can be developed independent of actual rainfall patterns. The main objective of this study is to establish guidelines on when this method can be adequately applied. The results based on the TCA are compared with those from the field observations and the Richards equation numerical solver for observed rainfall events and randomly generated rainfall patterns with prescribed temporal variabilities and hiatuses. For continuous rainfall with potential ponding, the maximum error of infiltration amount using the TCA-based method is less than 5%. The TCA-based method, in general, underestimates the total infiltration amount from variable rainfall events. Variance in rainfall time series does not significantly affect the errors of using the TCA-based method to determine the actual infiltration rate. The TCA-based method can produce reasonable results in simulating the actual infiltration rate for rainfall events with a short hiatus.


2017 ◽  
Vol 12 (6) ◽  
pp. 111 ◽  
Author(s):  
Adrian Wee Tiong Weng

Vietnam remains an exciting investment destination. Long term success in this East Asian country, however, requires effective management of resources including employees. This paper examines the literature and interviews with local employees in Ho Chi Minh City, Vietnam to identify cross-cultural communication and leadership issues at the international workplaces.   


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