Landscape‐specific thresholds in the relationship between species richness and natural land cover

Abstract Context : Biodiversity models postulate that the relationship between richness and the proportion of natural land cover (pNLC i.e., not dominated by human uses) is: 1) monotonic positive, 2) reasonably strong , 3) consistent in different geographic areas . Earlier work examining 100-km 2 human-dominated landcover in Ontario, Canada, observed that surveyed avian species richness is a peaked function of pNLC. Objective : We tested whether the same relationship between avian species richness and pNLC is also observed in an independent geographic area that has similar biomes. We also tested whether the peaked relations might be caused by temperature gradients, gradients in the size of species pools, grain size in the analyses, and landscape heterogeneity. Methods : Using breeding bird atlases of Ontario (Canada) and New York State (USA), we estimated species richness in landscapes varying from 25 to 900 km 2 . We related richness to the pNLC in each landscape and examined the same relationships after controlling for temperature, habitat heterogeneity, and species pool size. Results : Landscape-level species richness is a peaked, and not very strong function of pNLC. The relationship is not an artefact of temperature gradients, species pool size, or land cover heterogeneity. Conclusions : The proposition that increased amounts of natural land cover promotes species richness is clearly true at the limit, in landscapes with relatively little (<30%) natural cover. In landscapes with higher amounts of natural cover, a certain amount of human-modified land covers can provide habitat for species that prefer open habitats.

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Would conserving natural land cover in landscapes conserve biodiversity?

10.1101/436410 ◽

2018 ◽

Author(s):

Rafael X. De Camargo ◽

David J. Currie

Keyword(s):

New York ◽

Species Richness ◽

Land Cover ◽

Habitat Loss ◽

New York State ◽

Avian Species ◽

Distribution Data ◽

Species Loss ◽

York State ◽

Natural Land

ABSTRACTIt is generally accepted that protecting natural land cover would protect biodiversity. This would only be true as a general statement if the relationship between richness and natural land cover were monotonic positive and scale- and method-independent. Assertions about habitat loss causing species losses often come from broad-scale assessment of richness (e.g., from range maps) combined with patterns of natural habitat conversion. Yet, the evidence about species loss following habitat loss or fragmentation typically comes from fine-scale experiments. Here, we test whether broad-extent relationships between avian species richness and natural land cover are independent of: 1) whether species distribution data come from systematic censuses (atlases) versus range maps, and 2) the grain size of the analysis. We regressed census-based and range map-based avian species richness against the proportion of natural land cover and temperature. Censused richness at the landscape level was obtained from Breeding Bird Atlases of Ontario and New York State. Range-map richness derived from BirdLife International range maps. Comparisons were made across different spatial grains: 25-km2, 100-km2, and 900-km2. Over regional extents, range-map richness relates strongly to temperature, irrespective of spatial grain. Censused species richness relates to temperature less strongly. Range-map richness is a negative function of the proportion of natural land cover, while realized richness is a peaked function. The two measures of richness are not monotonically related to each other. In conclusion, the data do not indicate that, in practice, landscapes with greater natural land cover in southern Ontario or in New York State have higher species richness. Moreover, different data types can lead to dramatically different relationships between richness and natural land cover. We argue that the argument that habitat loss is the main driver of species loss has become a panchreston. It may be misguiding conservation biology strategies by focusing on a threat that is too general to be usefully predictive.

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Roadkill-Data-Based Identification and Ranking of Mammal Habitats

Land ◽

10.3390/land10050477 ◽

2021 ◽

Vol 10 (5) ◽

pp. 477

Author(s):

Andrius Kučas ◽

Linas Balčiauskas

Keyword(s):

Species Richness ◽

Land Cover ◽

Decision Support Techniques ◽

Mitigation Measures ◽

Spatial Decision Support ◽

Vehicle Collisions ◽

Vehicle Collision ◽

Ecological Corridor ◽

As Species ◽

The Relationship

Wildlife–vehicle collisions, as well as environmental factors that affect collisions and mitigation measures, are usually modelled and analysed in the vicinity of or within roads, while habitat attractiveness to wildlife along with risk to drivers remain mostly underestimated. The main goal of this study was the identification, characterisation, and ranking of mammalian habitats in Lithuania in relation to 2002–2017 roadkill data. We identified habitat patches as areas (varying from 1 to 1488 square kilometres) isolated by neighbouring roads characterised by at least one wildlife–vehicle collision hotspot. We ranked all identified habitats on the basis of land cover, the presence of an ecological corridor, a mammalian pathway, and roadkill hotspot data. A ranking scenario describing both habitat attractiveness to wildlife and the risk to drivers was defined and applied. Ranks for each habitat were calculated using multiple criteria spatial decision support techniques. Multiple regression analyses were used to identify the relationship between habitat ranks, species richness, and land cover classes. Strong relationships were identified and are discussed between the habitat patch ranks in five (out of 28) land cover classes and in eight (out of 28) species (97% of all mammal road kills). We conclude that, along with conventional roadkill hotspot identification, roadkill-based habitat identification and characterisation as well as species richness analysis should be used in road safety infrastructure planning.

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Land cover drives large scale productivity-diversity relationships in Irish vascular plants

PeerJ ◽

10.7717/peerj.7035 ◽

2019 ◽

Vol 7 ◽

pp. e7035 ◽

Cited By ~ 1

Author(s):

Hannah J. White ◽

Willson Gaul ◽

Dinara Sadykova ◽

Lupe León-Sánchez ◽

Paul Caplat ◽

...

Keyword(s):

Species Richness ◽

Land Cover ◽

Large Scale ◽

Vegetation Index ◽

Scale Effects ◽

Spatial Scales ◽

Vascular Plant ◽

Regional Scale ◽

The Impact ◽

The Relationship

The impact of productivity on species diversity is often studied at small spatial scales and without taking additional environmental factors into account. Focusing on small spatial scales removes important regional scale effects, such as the role of land cover heterogeneity. Here, we use a regional spatial scale (10 km square) to establish the relationship between productivity and vascular plant species richness across the island of Ireland that takes into account variation in land cover. We used generalized additive mixed effects models to relate species richness, estimated from biological records, to plant productivity. Productivity was quantified by the satellite-derived enhanced vegetation index. The productivity-diversity relationship was fitted for three land cover types: pasture-dominated, heterogeneous, and non-pasture-dominated landscapes. We find that species richness decreases with increasing productivity, especially at higher productivity levels. This decreasing relationship appears to be driven by pasture-dominated areas. The relationship between species richness and heterogeneity in productivity (both spatial and temporal) varies with land cover. Our results suggest that the impact of pasture on species richness extends beyond field level. The effect of human modified landscapes, therefore, is important to consider when investigating classical ecological relationships, particularly at the wider landscape scale.

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Seasonal changes in the relationship between species richness and community biomass in grassland under grazing and exclosure, Horqin Sandy Land, northern China

Sciences in Cold and Arid Regions ◽

10.3724/sp.j.1226.2013.00177 ◽

2013 ◽

Vol 5 (2) ◽

pp. 177 ◽

Cited By ~ 2

Author(s):

Zuo XiaoAn ◽

Zhao XueYong ◽

Zhang TongHui ◽

Wang ShaoKun ◽

Luo YaYong ◽

...

Keyword(s):

Species Richness ◽

Seasonal Changes ◽

Northern China ◽

Horqin Sandy Land ◽

Sandy Land ◽

Community Biomass ◽

The Relationship

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Modelling the relationship between climatic variables and land use/land cover classes in Yewa South Local Government Area of Ogun State, Nigeria

IOP Conference Series Materials Science and Engineering ◽

10.1088/1757-899x/1036/1/012003 ◽

2021 ◽

Vol 1036 (1) ◽

pp. 012003

Author(s):

S A Ojo ◽

J O Olusina ◽

B U Ngene ◽

D O Olukanni

Keyword(s):

Land Use ◽

Local Government ◽

Land Cover ◽

Local Government Area ◽

Climatic Variables ◽

Land Use Land Cover ◽

Ogun State ◽

The Relationship

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Assessment of Urban Thermal Field Variance Index and defining the relationship between land cover and surface temperature in Chattogram city: A remote sensing and statistical approach

Environmental Challenges ◽

10.1016/j.envc.2021.100107 ◽

2021 ◽

pp. 100107

Author(s):

Md. Nazmul Huda Naim ◽

Abdulla- Al Kafy

Keyword(s):

Remote Sensing ◽

Land Cover ◽

Surface Temperature ◽

Thermal Field ◽

Statistical Approach ◽

The Relationship ◽

Variance Index

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Relationships between resource availability and elevation vary between metrics creating gradients of nutritional complexity

Oecologia ◽

10.1007/s00442-020-04824-4 ◽

2021 ◽

Vol 195 (1) ◽

pp. 213-223

Author(s):

Mark A. Lee ◽

Grace Burger ◽

Emma R. Green ◽

Pepijn W. Kooij

Keyword(s):

Species Richness ◽

Plant Species ◽

Resource Availability ◽

Plant Biomass ◽

Plant Species Richness ◽

Mineral Contents ◽

Nutritive Values ◽

Animal Community ◽

Nutritional Chemistry ◽

The Relationship

AbstractPlant and animal community composition changes at higher elevations on mountains. Plant and animal species richness generally declines with elevation, but the shape of the relationship differs between taxa. There are several proposed mechanisms, including the productivity hypotheses; that declines in available plant biomass confers fewer resources to consumers, thus supporting fewer species. We investigated resource availability as we ascended three aspects of Helvellyn mountain, UK, measuring several plant nutritive metrics, plant species richness and biomass. We observed a linear decline in plant species richness as we ascended the mountain but there was a unimodal relationship between plant biomass and elevation. Generally, the highest biomass values at mid-elevations were associated with the lowest nutritive values, except mineral contents which declined with elevation. Intra-specific and inter-specific increases in nutritive values nearer the top and bottom of the mountain indicated that physiological, phenological and compositional mechanisms may have played a role. The shape of the relationship between resource availability and elevation was different depending on the metric. Many consumers actively select or avoid plants based on their nutritive values and the abundances of consumer taxa vary in their relationships with elevation. Consideration of multiple nutritive metrics and of the nutritional requirements of the consumer may provide a greater understanding of changes to plant and animal communities at higher elevations. We propose a novel hypothesis for explaining elevational diversity gradients, which warrants further study; the ‘nutritional complexity hypothesis’, where consumer species coexist due to greater variation in the nutritional chemistry of plants.

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