Shape is an objective characteristic of an object. A boundary separates a physical object from its surroundings. It defines the shape and regulates energy flux into and from an object. Visual ...perception of a definite shape (geometry) of physical objects is an abstraction. While the perceived geometry at an object's sharp interface (macro) creates a Euclidian illusion of actual shape, the notion of diffuse interfaces (micro) allows an understanding of the realistic form of objects. Here, we formulate a dimensionless geometric entropy of plant leaves (SL) by a 2-D description of a phase-field function. We applied this method to 112 tropical plant leaf images. SL was estimated from the leaf perimeter (P) and leaf area (A). It correlates positively with a fractal dimensional measure of leaf complexity, viz., segmental fractal complexity. Leaves with a higher P: A ratio have higher SL and possess complex morphology. The univariate cluster analysis of SL reveals the taxonomic relationship among the leaf shapes at the genus level. An increase in SL of plant leaves could be an evolutionary strategy. The results of morphological complexity presented in this paper will trigger discussion on the causal links between leaf adaptive stability/efficiency and complexity. We present SL as a derived plant trait to describe plant leaf complexity and adaptive stability. Integrating SL into other leaf physiological measures will help to understand the dynamics of energy flow between plants and their environment.
Anthrophony is an important determinant of habitat quality in the Anthropocene. Acoustic adaptation of birds at lower levels of anthrophony is known. However, threshold anthrophony, beyond which ...biophony starts decreasing, is less explored. Here, we present empirical results of the relationship between anthrophony and biophony in four terrestrial soundscapes. The constancy of the predicted threshold vector normalised anthropogenic power spectral density (~ 0.40 Watts/Hz) at all the study sites is intriguing. We propose the threshold value of anthropogenic power spectral density as an indicator of the avian acoustic tolerance level in the study sites. The findings pave the way to determine permissible sound levels within protected landscapes and directly contribute to conservation planning.
Abstract
More precise measurements of the complexity of leaf shapes can open new pathways to understanding plant adaptation and resilience in the face of global changes. We present a method to ...measure the complexity of plant leaf shapes by relating their fractal dimension to topological entropy. Our method relies on ‘segmental fractal complexity’ and stems from a fractal-thermodynamic system analogy. The complexity of plant leaf shapes is an algebraic combination of the fractal dimension of the components, leaf lamina, background, and leaf edge. We applied this method to leaf forms of 42 tropical plant species. Segmental fractal complexity is an improvement over the leaf dissection index because of its ability to capture the spatial positioning of a leaf’s lamina, edge, and background. It is also an advancement over conventional geometric and fractal dimension-based measures of leaf complexity because it does not entail information loss due to the pre-processing and is perceptibly simple.
•Plant leaves are considered as natural fractals.•Self-similar patterns in plant leaves are absent over the complete range of scales.•Traditional box-counting fractal analysis is area dependent and ...fails to capture the lacunarity.•The study makes plant scientists aware of the uncertainties in plant leaves' traditional box-counting fractal analysis.
Fractal-based measures have widespread applications in the characterization of complex biological structures. Box-counting is one of the most widely used methods of fractal analysis. However, the utility of traditional box-counting fractal analysis in complexity studies is limited. We discuss the shortfalls of traditional fractal dimension (D) approaches in leaf complexity studies. Mature and healthy flat leaves of 61 plant species were collected from Trivandrum, Kerala, India. Digital images of these leaves were analyzed using the ImageJ software. No significant variations in D were seen in the results that could differentiate the leaf forms. We present the limitations and biases affecting accurate D analysis. Fractal properties of plant leaves are restricted over a limited scale, causing the failure of the linear regression-based D estimates. Arbitrary grid placement and miscounting the boxes of a specific size to cover the leaves are also subject to quantization errors. Since traditional fractal analysis depends on the bulk and boundary of the leaves, some D errors result from the potential bias of this area dependency. The traditional box-counting analysis also fails to capture the lacunarity observed in leaf images. Hence an accurate estimation of D is challenging using conventional methods. Considering the broad utility of fractal methods, plant researchers must be sensitized about the uncertainties in traditional box-counting approaches in complexity studies.
The evolutionary success of a species is linked to its ability to communicate. Auditory, optic and olfactory systems are biological communication channels. Compared to the latter two, auditory ...systems are less impeded by physical obstructions. Successful species have effectively articulated this to their advantage. Decoding the acoustic dynamics of a landscape can ingeniously be crafted as a rapid tool to assess biological diversity. Here, we present results of the acoustic analysis carried out in three contrasting soundscapes in Kerala, India. Representative sound samples were recorded at Ernakulam, Kerala, India using Marantz PMD 661 III sonic recorder from 6.00 a.m. to 6.00 p.m. (IST) from an urban park Hill Palace Museum (L1), a sacred grove Iringole Kavu (L2), and a legally protected area Salim Ali Bird Sanctuary (L3). Acoustic characteristics of these sites expressed as Acoustic Complexity Index (ACI), Acoustic Diversity Index (ADI), Acoustic Evenness Index (AEI), Bioacoustic Index (BI) and Normalized Difference Soundscape Index (NDSI) were related to corresponding avian diversity. The objective finding reveals the distinctiveness of sonic characteristics and the status of diversity in each soundscape. Rapid assessment of biodiversity using acoustic indices is a prospective option that can be adopted as a means to generate biodiversity indicators of Sustainable Develeopment Goals (SDGs).
Wetlands for human well-being Ramachandra, T V; Asulabha, K S; Sincy, V ...
Journal of environmental biology,
03/2024, Letnik:
45, Številka:
2
Journal Article
Wetlands, transitional lands bridging the gap between terrestrial and aquatic ecosystems, are among the most diverse and productive ecosystems, with biophysical interactions that provide numerous ...ecological, economic, and social benefits for human wellbeing. These vital ecosystems sustain ecological processes to provide services such as nutrient cycling, water purification, reducing pollution, carbon sequestration, groundwater recharge, flood reduction, erosion control, habitats for aquatic biota, education opportunities, aesthetics, and recreation. Here, Ramachandra et al discuss the importance of wetlands.
Deforestation, fragmentation and fires are habitat transformers and responsible for loss of biodiversity. This study attempts to evaluate threat status of forest ecosystems by determining ...regional-level hot spots of deforestation, fragmentation and fires in Myanmar. The states of Ayeyarwady, Mandalay and Nay Pyi Taw have the highest annual rate of deforestation from 2005 to 2016. There is a significant reduction in spatial extent of large core forest. Mandalay and Nay Pyi Taw had shown more than 20% of loss in large core forest from 2005 to 2016. Geospatial analysis indicates all the major forest types were affected by fires during 2003 to 2017. The study found that dry deciduous forests were highly affected by fires. More than 60% of the forest area of Magway, Mandalay, Chin, Kayah, Kayin and Shan had found to be under forest fire hot spot. Comparative spatial assessment was carried out on fire hot spots, deforested and fragmented landscapes to provide overview of priority conservation areas. The study identified five states in Myanmar affected by multiple threats and categorised as Conservation Priority Hot Spot I, eight states as Conservation Priority Hot Spot II and two states as low-risk areas categorised as Conservation Priority Hot Spot III. The analysis of hot spots of deforestation, fragmentation and fires provides a consistent way of ecosystem monitoring and biodiversity conservation in Myanmar. The study demonstrates repeatable earth observations as an important prerequisite for sustainable forest management in Myanmar.
Spatially explicit approach is essential to prioritise the ecosystems for biodiversity conservation. In the present study, the conservation status of 20 protected areas of the Western Ghats of ...Kerala, India, was analysed based on long-term changes in forests (1975–1985–1995–2005–2013), landscape level changes in fragmentation and forest fires (2005–2015). This study has shown that a significant forest loss occurred in protected areas before declaration. Idukki is one of the major protected areas which showed a drastic reduction (18.83%) in its forest cover. During 1985–1995, Periyar tiger reserve had lost 24.19 km
2
core 3 forest area followed by Peppara (18.54 km
2
), Parambikulam (17.93 km
2
), Chimmony (17.71 km
2
), Peechi-Vazhani (12.31 km
2
) and Neyyar (11.67 km
2
). An area of 71.33 km
2
of the protected area was affected by fires in 2014. Overall protected area-wise decadal analysis indicates Periyar has the highest number of fire incidences followed by Wayanad, Kurinjimala, Silent Valley and Eravikulam. Disturbances in the form of fires and fragmentation still exist and may have significant conservation threat to flora and fauna. Among protected areas, many are having a probability to go under threat or dynamic stage. Chinnar, Thattekkad and Kurinjimala sanctuaries are representing high levels of vulnerability, or they are near to decline stage. Habitat level monitoring of the anthropogenic disturbances can be efficiently useful for the strategic conservation planning. The present study has provided geospatial database on spatial patterns of deforestation, fragmentation and forest fires in protected areas of Kerala. Conservation prioritization approach based on these parameters will be useful for the strategic planning in the state of Kerala.
•Explicate surrogacy of acoustic indices for rapid assessment of avian diversity.•Compares pre and post flood avian diversity using acoustic indices.•Acoustic estimation of biodiversity act as a ...travellator to realize conservation goals.
Biodiversity assessment, in the aftermath of a natural disaster, remains a challenge. Sonic (acoustic) analysis is increasingly gaining acceptance as a means of rapid assessment of biodiversity. However, its utility in the immediate aftermath of natural disasters is unreported. We compare pre-flood, flood-period and post-flood acoustic indices of Salim Ali Bird Sanctuary, Kerala, India, to illustrate their utility in assessing avian biodiversity. The temporal dynamics of acoustic indices capture the spectre of floods on avian diversity and its resurgence with time in the sanctuary.
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