Dog feces and urine could be harming nature reserves, according to new
study

Date:
February 7, 2022
Source:
British Ecological Society
Summary:
New research finds that dogs being walked in nature reserves
contribute a significant amount of nutrients to the environment
through their feces and urine, which researchers warn could
negatively impact local biodiversity.



FULL STORY ==========================================================================
New research finds that dogs being walked in nature reserves contribute
a significant amount of nutrients to the environment through their
faeces and urine, which researchers warn could negatively impact local biodiversity. The research is published in the British Ecological Society journal, Ecological Solutions and Evidence.


========================================================================== Significant levels of fertilisation Researchers at Ghent University
have estimated that each year dog faeces and urine add an average of
11kg of nitrogen and 5kg of phosphorus per hectare to nature reserves
near the Belgian city of Ghent. The researchers say that the nutrients
added through this neglected form of fertilisation are substantial and
could be detrimental to biodiversity and ecosystem functioning.

The estimates for the amount of nitrogen being added by this previously unrecorded source are particularly significant when compared to the
total levels of nitrogen being added across most of Europe through fossil
fuel emissions and agriculture, which range from 5 to 25kg of nitrogen
per hectare.

Professor Pieter De Frenne of Ghent University and lead author of the
research said: "We were surprised by how high nutrient inputs from dogs
could be.

Atmospheric nitrogen inputs from agriculture, industry and traffic
rightfully receive a lot of policy attention, but dogs are entirely
neglected in this respect." The researchers call for land managers,
especially in low nutrient ecosystems, to emphasise the negative
fertilisation effects of dogs to visitors, encouraging them to remove
their dogs' faeces. They also call for leash use to be enforced more stringently and the establishment of more off-leash dog parks to reduce
the pressure on nature reserves.



==========================================================================
Dogs on leashes and owners removing faeces have big impacts In the
experiment, which calculated the amount of nutrients dogs were adding to
the environment by recording the number of dogs present in four nature reserves, the researchers modelled different scenarios including if the
dogs were on or off leashes and if owners picked up dog faeces.

When the researchers modelled a scenario where all dogs were kept on
leashes (legally required in all these reserves) they found that this
reduced the fertilisation rates in the largest part of the reserves
but strongly increased fertilisation rates in the small areas around
paths. Over a year this input was as high as 175 kg of nitrogen and 73
kg of phosphorus per hectare.

Professor De Frenne said: "In our scenario where all dogs were kept
on leashes, we found that in these concentrated areas around paths,
nutrient inputs of both nitrogen and phosphorus exceeded legal limits
for fertilization of agricultural land. Which is quite staggering as
our study concerned nature reserves!" In a scenario where dogs were on leashes, but all owners picked up their dogs' faeces, the researchers
found that this reduced fertilisation levels by 56% for nitrogen and
97% for phosphorus. This is due to dog faeces accounting for nearly all phosphorus being deposited whereas nitrogen is deposited equally by both
faeces and urine.



========================================================================== Increased nutrients a problem for nature reserves The addition of
nutrients to nature reserves might sound beneficial as these lead
to increased plant growth, however, this mostly occurs in a limited
number of nutrient demanding species that outcompete rarer specialists, reducing biodiversity.

"In many nature reserves, the management is specifically directed
towards lowering soil nutrient levels to enhance plant and animal
biodiversity. This can be done through methods like mowing and hay
removal." Explains Professor De Frenne. "Our findings suggest that
the currently neglected inputs of dogs in nature reserves could delay restoration goals." Calculating nutrient levels To estimate the amount
of nutrients dogs were adding to the environment, the researchers first calculated dog abundance per hectare, per year, by counting dogs in
four nature reserves close to the city of Ghent, Belgium. These counts
were performed on 487 occasions over 18 months. They then performed a literature search of nutrient concentrations in dog urine and faeces to
model different scenarios.

While this method meant that researchers could accurately calculate the abundance of dogs in the nature reserves, estimations had to be made
based on the average dog and average volumes of urine and mass of faeces,
as well as estimates of nitrogen and phosphorus concentrations.

The researchers say that their data could be improved by recording breeds
of dogs, as well as their size, weight and the number of urine and faecal deposits, for instance, by asking owners. The researchers also suggest
that georeferencing dog faeces and urine locations could further help
to detect fertilisation 'hot spots'.

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always get wrong about diet and exercise. Claim_yours_now_>>> ========================================================================== Story Source: Materials provided by British_Ecological_Society. Note:
Content may be edited for style and length.


========================================================================== Journal Reference:
1. Pieter De Frenne, Mathias Cougnon, Geert P. J. Janssens, Pieter
Vangansbeke. Nutrient fertilization by dogs in peri‐urban
ecosystems. Ecological Solutions and Evidence, 2022; 3 (1) DOI:
10.1002/ 2688-8319.12128 ==========================================================================

Link to news story: https://www.sciencedaily.com/releases/2022/02/220207083438.htm

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