Chaotic summer weather patterns have heightened concerns that climate change could have a serious impact on Scotland's wildlife, flora and fauna, it emerged yesterday.

Arthur Martin, head of countryside and nature conservation services at the National Trust for Scotland (NTS), said the unpredictable weather had started to take its toll on the delicate balance of the country's natural landscape.

A number of species have appeared in Scotland for the first time, while the survival of some montane plants and birds are at greater risk given a general rise in temperature.

Nuthatches, which have in the past been restricted to England, bred this summer at the NTS's Harmony Gardens in Melrose and another property in East Lothian.

Mr Martin said: "We cannot be certain that this is due to climate change but warning bells are ringing very loudly.

"We are particularly concerned for montane species such as the mountain-top living birds such as ptarmigan or the rare alpine plants that are found at some of our upland properties, such as Ben Lawers National Nature Reserve in Perthshire or the Grey Mare's Tail in the Scottish Borders close to Moffat."

The Ben Lawers reserve is a world interest site for arctic and sub-alpine plant species, which include mountain pansy, alpine forget-me-not and a variety of willow scrub.

"Upward changes in temperature could result in the loss of these species from Scotland," Mr Martin said.

A reduction in snow cover has been noted at the most northerly NTS properties, indicating significant temperature change, and as footpaths become exposed for longer each year it puts them at risk of accelerated erosion.

Mr Martin said: "Over the past 10 years, working in partnership with Scottish Natural Heritage and the Heritage Lottery Fund, the NTS has spent about £2m on the repair and maintenance of these paths, but the loss of the protective snow cover and increased heavy rain storms, which are associated with climate change, could be particularly damaging to footpaths and demand much higher levels of maintenance just to achieve the status quo."

Similar worries have been expressed by the National Trust which serves England, Wales and Northern Ireland.

Many species emerged or bred earlier because of warm weather in the first few months of the year, while the heavy rain and low temperatures in the summer caused problems for insects, birds and bats.

The National Trust's nature conservation adviser, Matthew Oates, said a male goldeneye duck was displaying in Northern Ireland in January, months earlier than usual, while bats were on the wing in late March, long before the usual time.

Ladybirds, bumblebees, peacock butterflies and frogspawn all had an early start in February, and the good weather in April saw adonis blue and marsh fritillary butterflies on the wing "radically" early.

And in October, basking sharks were spotted for the first time off the Farne Islands - the plankton they feed on is not normally found in the North Sea at that time of year.